Three families in the pediatric hematology clinic share a structural communication challenge: each family observes a positive clinical state — fourteen months without a pain crisis, a child who is not bleeding despite low platelets, four years of good health after a surgery that removed a disease — and each family reasons from that positive state toward reducing an intervention, not knowing that the positive state is either produced by the intervention working continuously or contingent on a protection that was permanently removed. Miguel’s fourteen crisis-free months are fetal hemoglobin at 32% preventing HbS polymerization in every red blood cell every day; the HbSS genotype is unchanged and the polymerization potential is restored within six to eight weeks of stopping hydroxyurea. Valentina’s current stability at 28,000 platelets does not call for steroids — steroid-induced remission in chronic ITP relapses in 80% of cases within weeks because T-cell-mediated dysregulation, not just autoantibodies, is the driver, and 28,000 without active bleeding is above the serious bleeding threshold where treatment benefit outweighs steroid side effects. Carlos’s four years of post-splenectomy health are possible because penicillin V is daily compensating for the marginal-zone IgM production and sinusoidal macrophage filtration that splenectomy permanently removed along with the disease-causing premature red cell destruction.
Miguel Orozco-Herrera, 9 years old, Houston, Texas — homozygous HbSS sickle cell disease on hydroxyurea, Hb F 32%, zero vaso-occlusive crises in fourteen months, mother requesting hydroxyurea discontinuation
Miguel was identified at three days of age through Texas newborn screening. HPLC and hemoglobin electrophoresis confirmed HbSS: the beta-globin gene c.20A>T p.Glu7Val variant is present on both alleles. No Hb A is produced. His childhood course was typical for HbSS: two hospitalizations for acute chest syndrome at ages four and six, vaso-occlusive pain crises requiring emergency department visits at an average of twice per year through age seven, hemolytic anemia with baseline hemoglobin 7.4–8.1 g/dL, and a single clinically silent cerebral infarct detected on brain MRI at age five years and four months. Hydroxyurea was started at age six years and seven months and titrated over fourteen months to 20 mg/kg/day. Current parameters: Hb F 32% by HPLC, MCV 101 fL (up from 80 fL pre-hydroxyurea), hemoglobin 9.8 g/dL, absolute reticulocyte count and LDH both reduced from pre-hydroxyurea baseline — markers of reduced hemolysis. In the thirty-one months on hydroxyurea, including the past fourteen, Miguel has had zero vaso-occlusive pain crises requiring emergency care and zero hospitalizations.
His mother, Graciela Orozco-Torres, thirty-four, hotel housekeeper, arrives today with a clear question: fourteen months without a single crisis, Miguel is in fourth grade and keeping up, and hydroxyurea is causing some GI discomfort and fatigue. She found a site suggesting some children can reduce medications when they are doing well. She wants to know if it is time to stop.
Nurse Carmen Fuentes-Espinoza knows that Graciela’s reasoning is coherent from her observation. The explanation begins with the molecular event hydroxyurea is preventing.
The c.20A>T p.Glu7Val substitution places a hydrophobic valine residue at the sixth position of the beta-globin chain in place of the hydrophilic glutamic acid normally present. In the oxygenated R-state, this substitution is accommodated without consequence. When the red blood cell delivers oxygen to tissue and hemoglobin transitions to the deoxygenated T-state, the valine-6 residue becomes exposed on the molecular surface and fits precisely into a hydrophobic acceptor pocket formed by phenylalanine-85 and leucine-88 on an adjacent HbS molecule in its T-state conformation. This intermolecular contact initiates fiber nucleation: the molecules stack into double-strand helical polymer fibers. Fiber formation is exquisitely sensitive to HbS concentration — the delay time before a nucleation event occurs drops exponentially with increasing HbS fraction. Even a modest reduction in HbS fraction through HbF dilution dramatically extends the delay time before polymerization begins, potentially beyond the transit time for a red blood cell to pass through tissue capillaries (approximately one to two seconds) and re-oxygenate in venous blood.
Fetal hemoglobin (Hb F, α2γ2) disrupts polymerization through two mechanisms operating simultaneously. First, the γ-globin chain carries threonine at position 6 rather than the valine that creates the intermolecular contact in HbS polymerization. A hybrid tetramer containing α-globin and γ-globin (an Hb F molecule) can engage in initial intermolecular contacts but cannot be incorporated into a growing HbS polymer fiber because the γ-globin chain lacks the complementary contact geometry required for fiber incorporation. Hybrid tetramers containing one γ-globin chain terminate fiber elongation at the point of contact. Second, Hb F molecules dilute the concentration of HbS tetramers available for nucleation events. At Hb F 32%, the polymerization kinetics in Miguel’s red blood cells are shifted far enough toward the safe range that under normal physiologic deoxygenation conditions — oxygen partial pressure of 30–50 mmHg in tissue capillaries — the polymerization delay time exceeds capillary transit time. His red blood cells traverse tissue capillaries and return to venous oxygen tension without polymerizing. The fourteen months without a crisis are not evidence that the HbSS disease has receded. The HbSS genotype is present in every erythroid precursor, every reticulocyte, and every circulating red blood cell today. What changed at the start of hydroxyurea treatment was the Hb F concentration — and the fourteen crisis-free months are that concentration working every minute in every red blood cell.
Hydroxyurea produces Hb F elevation by inhibiting ribonucleotide reductase, the enzyme that catalyzes the rate-limiting conversion of ribonucleotides to deoxyribonucleotides for DNA synthesis. This inhibition arrests dividing cells in S-phase, specifically the rapidly cycling erythroid progenitors in the bone marrow. The S-phase arrest activates hypoxia-inducible factor 1α (HIF-1α) in erythroid precursors. HIF-1α transactivates the γ-globin promoter — the same promoter that was actively expressed in fetal erythropoiesis and silenced after birth through CpG methylation of the promoter and repression by the BCL11A transcription factor. Hydroxyurea also generates nitric oxide as a metabolic byproduct that contributes to cGMP-mediated γ-globin gene activation in erythroid precursors. The combined effect is a shift from adult-pattern (β-globin dominant) to partial fetal-pattern (γ-globin re-expressed) erythropoiesis in bone marrow progenitors, producing new red blood cells with substantially elevated Hb F content.
This mechanism is pharmacodynamically dependent on continuous daily dosing. When hydroxyurea is stopped, ribonucleotide reductase returns to normal activity within days. The HIF-1α signal disappears. Over the following three to four weeks, the BCL11A repressor and CpG methylation re-establish progressive epigenetic silencing of the γ-globin promoter in erythroid progenitors. New red blood cells forming during this period contain progressively less Hb F. Because HbSS red blood cells have a shortened lifespan of approximately 17–25 days due to hemolysis (far shorter than the normal 120-day erythrocyte lifespan), the circulating Hb F level reflects the Hb F content of cells produced over the preceding few weeks. Hb F falls from 32% to the pre-hydroxyurea baseline of approximately 3–5% within six to eight weeks of stopping treatment. Once Hb F falls below the protective threshold, the polymerization delay time in tissue capillaries is no longer reliably sufficient to prevent sickling. Miguel’s next febrile illness — fever raises metabolic rate and increases tissue oxygen demand, lowering mixed venous oxygen tension — will encounter red blood cells in which HbS polymerization can occur under the resulting hypoxic conditions. Pain crises return not because the disease changed but because the molecular protection was removed.
Nurse Carmen addresses the fatigue and GI discomfort directly: these side effects are dose-related and manageable through dose adjustment and dietary counseling without stopping hydroxyurea. The slight hemoglobin decrease some families observe reflects the bone marrow suppression that is hydroxyurea’s mechanism of action — it is the S-phase arrest of erythroid progenitors that drives Hb F production. Hydroxyurea’s net effect on hemoglobin in HbSS is typically positive or neutral because reducing hemolysis (Hb F-containing red blood cells are more durable) offsets the mild marrow suppression. The fatigue is unlikely to be from anemia and most likely reflects a dose effect that can be titrated. Carmen offers Graciela the reframe: the fourteen-month diary of empty crisis rows is not evidence that Miguel has outgrown the need for hydroxyurea. It is evidence that hydroxyurea has been working every day for fourteen months, preventing the polymerization event that sent him to the emergency department twice a year before.
Valentina Morales-Cruz, 7 years old, San Antonio, Texas — chronic ITP with platelets 28,000/μL, no active bleeding, mother requesting steroid treatment
Valentina was first diagnosed with immune thrombocytopenia at age five years and two months following extensive bruising and petechiae after a viral upper respiratory illness. Initial platelet count was 8,000/μL. She received three courses of high-dose dexamethasone over the following fourteen months, achieving platelet responses of approximately 150,000–210,000/μL after each course and relapsing to 19,000–31,000/μL within six to eight weeks of each course completion. ITP was reclassified as chronic at sixteen months from diagnosis. Over the subsequent ten months without steroid treatment, her platelet count has ranged from 17,000 to 42,000/μL. She has had petechiae on her lower legs when counts fall below 20,000 but no mucosal bleeding, no purpura, no significant epistaxis, and no gastrointestinal bleeding.
Today’s platelet count is 28,000/μL. Her mother Rosa Morales-Torres, thirty-eight, school cafeteria worker, has printed a page from a patient ITP advocacy website describing steroids as first-line ITP treatment and listing prednisone and dexamethasone as standard medications. She wants to know why Valentina is not receiving steroids and whether the hematology team is “waiting for something bad to happen.”
Nurse Patricia Solano-Torres recognizes that Rosa’s concern is understandable given the information she found and that addressing it requires first validating that what she read is accurate for newly diagnosed ITP, then distinguishing why chronic ITP follows different management logic.
Immune thrombocytopenia results from autoimmune destruction of platelets. IgG autoantibodies directed against platelet surface glycoproteins — predominantly GPIIb/IIIa and GPIb–IX — bind to circulating platelets, which are then phagocytosed by Fcγ-receptor-bearing macrophages predominantly in the spleen. In some patients, autoantibodies also bind megakaryocytes — platelet precursors — reducing platelet production. In newly diagnosed ITP, within three months of diagnosis, the disease process is principally antibody-driven. A steroid course at this stage achieves a platelet response in 70–80% of patients through multiple mechanisms: lymphocyte apoptosis reducing autoantibody-producing B cell populations, inhibition of immunoglobulin synthesis, reduced Fc receptor expression on splenic macrophages, and alteration of platelet trafficking. In the newly diagnosed ITP context, steroids are appropriately first-line and the consumer health information Rosa found is accurate.
Chronic ITP — as in Valentina’s case, persisting for more than twenty-six months — has accumulated immunological changes that make steroid-induced remission transient and predictably temporary. Beyond the original antibody-mediated component, chronic ITP is sustained by T-cell-mediated immune dysregulation: cytotoxic CD8+ T cells directly lyse platelets through perforin-mediated pathways independent of antibody opsonization; Th1 and Th17 helper T cells maintain the proinflammatory cytokine environment that drives continued autoantibody production by B cells; and CD4+CD25+FoxP3+ regulatory T cells (Tregs) — the cells that normally suppress autoreactive effector T cells — are numerically reduced and functionally impaired in chronic ITP patients compared to age-matched controls. Steroid treatment suppresses the B-cell antibody production component through lymphocyte apoptosis. It does not eliminate the autoreactive T-cell clones driving the disease, does not correct the Treg deficiency, and does not resolve the underlying immune dysregulation. When steroids are stopped, the T-cell-mediated platelet attack resumes from the same baseline the steroids temporarily suppressed. This is the mechanism of the relapse pattern Valentina’s own history demonstrates: each dexamethasone course produced the same initial response and the same six-to-eight-week relapse.
Published pediatric chronic ITP cohort data confirm this pattern: approximately 80% of children with chronic ITP who achieve a platelet response to a steroid course relapse within twelve weeks of completing that course. Only 20–30% achieve durable remission from steroid courses alone. Each additional course adds cumulative side effect risk: growth velocity suppression from HPA axis feedback inhibition, Cushingoid features including central adiposity and striae, glucose intolerance, hypertension, bone mineral density loss increasing fracture risk, posterior subcapsular cataracts, and adrenal insufficiency risk during acute illness. For a seven-year-old in active growth, multiple steroid courses with predictably transient benefit carry a side effect profile that the 2019 American Society of Hematology ITP guideline specifically weighs against watchful waiting when there is no active serious bleeding.
The 2019 ASH ITP guideline recommends watchful waiting for children with chronic ITP without active bleeding and platelet counts above approximately 20,000 per microliter. This threshold is derived from the clinical evidence on bleeding risk: serious spontaneous bleeding events in otherwise healthy children with ITP — intracranial hemorrhage, severe gastrointestinal bleeding, severe mucosal bleeding — occur predominantly at counts below 10,000 to 20,000/μL. The platelet count alone is an imperfect predictor of bleeding: the same count of 28,000 in one patient is associated with daily petechiae while another patient is asymptomatic, because platelet function, thrombopoietin levels, and individual vessel fragility vary. What matters clinically is whether the patient is in a serious bleeding range. Valentina at 28,000 with no mucosal bleeding, no progressive purpura, no epistaxis beyond five minutes, and no GI bleeding is not in that range.
Nurse Patricia explains to Rosa that the team is not waiting for something bad to happen — they are actively choosing the evidence-based approach that avoids exposing Valentina to predictably temporary treatments with cumulative growth and endocrine side effects while she is clinically stable. The team will offer treatment when it is indicated: platelet count below 20,000 with mucosal bleeding, pre-surgical need for higher count, or any change in the bleeding risk assessment. Other treatment options available if the situation changes include IVIG for rapid short-term elevation before a procedure, and thrombopoietin receptor agonists (eltrombopag, romiplostim) that stimulate platelet production directly from megakaryocytes, bypassing the autoimmune attack on circulating platelets. None are indicated today given that watchful waiting at 28,000 without active bleeding is the appropriate management.
Carlos Cisneros-Vega, 10 years old, Dallas, Texas — hereditary spherocytosis four years post-splenectomy, penicillin V 250 mg twice daily, father requesting antibiotic discontinuation
Carlos was diagnosed with hereditary spherocytosis at age two years and one month after persistent pallor, intermittent jaundice, and fatigue. CBC showed hemoglobin 7.1 g/dL, MCHC 37.2 g/dL, and spherocytes on peripheral smear comprising approximately 30% of red blood cells. Osmotic fragility and EMA binding assay confirmed spectrin deficiency. Molecular testing identified SPTA1 heterozygous c.779T>C p.Leu260Pro, a pathogenic spectrin variant also present in his paternal grandmother. Between ages two and six Carlos required transfusions every six to ten weeks to maintain hemoglobin above 8.5 g/dL. Laparoscopic splenectomy was performed at age six years and two months. Hemoglobin stabilized at 12.4 g/dL post-operatively and has been stable for forty-eight months. He has required no transfusions since. He has been on penicillin V 250 mg twice daily since splenectomy, is current on PCV20 and meningococcal vaccines, and has had no serious infections.
Today Eduardo Cisneros-Torres, forty-two, warehouse supervisor, asks to stop the penicillin. Carlos is ten years old, four years post-splenectomy, healthy, active, and playing youth soccer. Eduardo researched online and found mixed information about antibiotic duration. A family at their church whose son had a splenectomy for a different reason stopped the antibiotic at age eight on different specialist advice. He asks whether the risk is still real after four years.
Nurse Lucia Vargas-Reyes needs to introduce a concept that is counterintuitive: that the same surgery removed two functions simultaneously, and the cured one was the visible one. The permanent loss was the invisible one.
Hereditary spherocytosis is caused by mutations in red blood cell membrane skeleton proteins. The SPTA1 c.779T>C p.Leu260Pro variant produces αI-spectrin chains with reduced self-association stability, impairing the tethering of the inner lipid bilayer leaflet to the membrane skeleton. As mature spherocytic red blood cells circulate repeatedly through the spleen’s sinusoids — narrow passages between adjacent endothelial cells with gaps of 1–2 microns — their weakened membrane skeleton cannot sustain the deformation required to squeeze through. Normal red blood cells deform elastically. Spherocytes lose membrane surface area through fragmentation at each failed passage attempt and are progressively entrapped and phagocytosed by splenic macrophages. The result is extravascular hemolytic anemia requiring transfusions. Splenectomy removes the site of premature destruction. Carlos’s SPTA1 variant still produces spherocytes — every red blood cell he makes is a spherocyte — but they now circulate until natural senescence because the splenic quality-control gate has been removed. His hemoglobin rose to 12.4 g/dL and has stayed there. Eduardo is correct: the spleen problem is fixed. The anemia is cured.
The immunological architecture of the spleen is anatomically intermingled with but functionally distinct from the red pulp quality-control function. The white pulp and marginal zone of the spleen house several immunologically specialized cell populations that have no relationship to hemolytic anemia or spherocyte clearance. Marginal zone B cells are a population of long-lived B lymphocytes positioned at the interface between the splenic marginal zone and the blood-borne antigen stream. They are specialized for T-cell-independent immune responses: because encapsulated bacteria including Streptococcus pneumoniae, Haemophilus influenzae type b, and Neisseria meningitidis express polysaccharide capsid antigens that cannot activate T cells (T cells require protein antigens for activation), the primary rapid defense against these organisms must bypass T-cell help. Marginal zone B cells recognize polysaccharide antigens directly and produce IgM antibodies within hours — faster than a classical T-cell-dependent B-cell response. This rapid IgM response opsonizes encapsulated bacteria in the bloodstream, marking them for phagocytosis by neutrophils and systemic macrophages. In addition, the splenic red pulp sinusoidal macrophages — which are different from the macrophages that phagocytose spherocytes — filter unopsonized bacteria directly from the bloodstream through non-specific phagocytosis, exploiting the unique hemodynamic architecture of the splenic red pulp where blood flow nearly stalls in the cord spaces before being forced through the 1–2 micron interendothelial slits into venous sinuses, bringing bacteria into prolonged macrophage contact. This sinusoidal filtration function requires the physical structure of the spleen and cannot be replicated elsewhere in the body.
Splenectomy removes both the quality-control mechanism (curing the anemia) and the immunological architecture (creating a permanent immune deficit for encapsulated organisms). The marginal zone B cells are gone. The sinusoidal macrophages are gone. There is no other organ that regenerates these functions. After splenectomy, when S. pneumoniae enters Carlos’s bloodstream — from a bacteremic episode during a respiratory illness, a dental procedure, or any other source — the bacteria encounter only circulating IgG antibodies from prior vaccination (present at lower titers than the splenic IgM response would have generated) and circulating neutrophils and monocytes, which are effective phagocytes but require opsonization that takes hours to reach maximum efficiency. If the organism multiplies faster than these non-splenic defenses can control, bacteremia progresses to septicemia.
Overwhelming post-splenectomy infection (OPSI) is the clinical syndrome that results. S. pneumoniae causes 50–70% of OPSI cases. The clinical course is distinctive in its rapidity: an initial presentation indistinguishable from any other febrile illness progresses to septic shock with disseminated intravascular coagulation within twelve to twenty-four hours. OPSI mortality once septic shock establishes is 50–70% — substantially higher than pneumococcal sepsis in immunocompetent patients, because the asplenic patient lacks both the marginal zone IgM that would have opsonized the organisms within hours of initial bacteremia and the sinusoidal filtration that would have cleared them before they reached systemic concentrations. The lifetime risk of OPSI in splenectomized children is approximately 1–2%, concentrated in the first two years post-splenectomy but measurably elevated for life compared to age-matched children with intact spleens.
This risk does not diminish with time because the structural loss is permanent. The splenic sinusoids that filtered bacteremia are absent and do not regenerate. Carlos at age ten has the same structural deficit for encapsulated organisms that he had at age six post-operatively. The four years of good health reflect the penicillin providing bactericidal coverage against the organisms his absent spleen can no longer intercept, combined with vaccination providing partial serotype-specific protection. The church family’s decision to stop antibiotics at age eight may reflect different underlying circumstances, a different specialist recommendation, or a different family risk tolerance; it does not change the OPSI risk calculation for Carlos.
Penicillin V 250 mg twice daily achieves bactericidal blood concentrations against S. pneumoniae within one to two hours of oral dosing. Current guidance from the American Society of Hematology and the Advisory Committee on Immunization Practices recommends antibiotic prophylaxis in children with functional asplenia for hereditary hemolytic anemias for at minimum through age five and for at least three to five years post-splenectomy, with many centers and guidelines recommending continuation through childhood and into adolescence or adulthood because the risk never fully returns to baseline.
Nurse Lucia gives Eduardo a concrete framework: two things were removed by the splenectomy. The first was the site where Carlos’s abnormal red blood cells were trapped and destroyed, causing the anemia — that is permanently cured and requires nothing. The second was the primary immune defense against certain bacteria in the bloodstream — that is permanently absent and requires the penicillin to compensate for it. The hereditary spherocytosis is cured. The immune deficit is structural and permanent. The penicillin is not for the spherocytosis. It is for the part of the immune system that left with the spleen.
The three scenarios in this post share a structural pattern across the pediatric hematology clinic: families who observe a positive clinical outcome — months without pain crises, a child who is not bleeding, years of health after a curative surgery — and reason from that outcome toward reducing the intervention, not knowing that the positive outcome is either produced by the intervention working continuously or dependent on a protection that has already been permanently removed. Miguel’s fourteen crisis-free months are Hb F at 32% preventing HbS polymerization every day, not a remission of the HbSS disease itself; stopping hydroxyurea removes the Hb F elevation and restores polymerization-driven sickling within six to eight weeks. Valentina’s current stability at 28,000 is not evidence for a steroid course — it is evidence that watchful waiting is working, and the 80% relapse rate of steroid-induced remission in chronic ITP means each course exposes her to cumulative side effects without durable benefit above the serious-bleeding threshold. Carlos’s four years of post-splenectomy health are contingent on penicillin V compensating for the permanently absent marginal-zone IgM and sinusoidal macrophage filtration; the surgery cured the anemia and removed the immune defense, and the structural immune deficit never resolves.
The nurse who understands these mechanisms can reframe each management decision from “excessive given the outcome” to “necessary because the outcome depends on the management.” Fourteen crisis-free months are not evidence that hydroxyurea is no longer needed — they are evidence that Hb F elevation is working daily and would be lost within six to eight weeks of stopping. Chronic ITP at 28,000 is not evidence for another steroid course — it is evidence that watchful waiting is the appropriate choice for a count above the serious-bleeding threshold when steroid remission in chronic ITP has an 80% relapse rate. Four years of healthy post-splenectomy life are not evidence that penicillin can stop — they are evidence that the bactericidal coverage is successfully compensating for the permanent structural immune deficit that splenectomy produces and that will not resolve.
Six key Spanish phrases for the pediatric hematology clinic
- La hemoglobina fetal del 32 por ciento ES la hidroxiurea funcionando — impide que la hemoglobina S se polimerice en los capilares y produzca las crisis de dolor. La mutación no cambió: los 14 meses sin crisis son el medicamento trabajando todos los días. Si dejamos la hidroxiurea, el gen de hemoglobina fetal se silencia de nuevo en tres a cuatro semanas, el nivel baja al 3–5 por ciento en seis a ocho semanas, y la próxima fiebre o esfuerzo desencadena la polimerización y la crisis regresa. — The 32 percent fetal hemoglobin IS the hydroxyurea working — it prevents hemoglobin S from polymerizing in capillaries and producing pain crises. The mutation did not change: the 14 months without crises are the medication working every day. If we stop hydroxyurea, the fetal hemoglobin gene silences again in three to four weeks, the level falls to 3–5 percent in six to eight weeks, and the next fever or exertion triggers polymerization and the crisis returns.
- La hemoglobina fetal bloquea la polimerización de dos maneras: diluye la hemoglobina S disponible para nuclearse y termina activamente el crecimiento de la fibra polímerica porque las cadenas gamma no se incorporan en el polímero de hemoglobina S. Estas dos acciones juntas desplazan la cinética de polimerización de Miguel fuera del rango peligroso bajo condiciones fisiológicas normales. Sin la hemoglobina fetal alta ese equilibrio desaparece. — Fetal hemoglobin blocks polymerization in two ways: it dilutes the available hemoglobin S for nucleation and actively terminates polymer fiber growth because gamma chains cannot be incorporated into the hemoglobin S polymer. These two actions together shift Miguel's polymerization kinetics out of the dangerous range under normal physiologic conditions. Without high fetal hemoglobin that balance disappears.
- El 80 por ciento de los niños con PTI crónica tienen recaída en pocas semanas después de terminar un curso de esteroides porque la PTI crónica también tiene un componente de células T que los esteroides no corrigen de forma duradera. A 28,000 plaquetas sin sangrado activo, Valentina está por encima del umbral donde ocurre el sangrado grave espontáneo en niños sanos. La guía de la Sociedad Americana de Hematología recomienda observación en esta situación. — 80 percent of children with chronic ITP relapse within weeks of finishing a steroid course because chronic ITP also has a T-cell component that steroids do not correct durably. At 28,000 platelets without active bleeding, Valentina is above the threshold where serious spontaneous bleeding occurs in otherwise healthy children. The American Society of Hematology guideline recommends watchful waiting in this situation.
- Cada curso de esteroides agrega riesgos acumulativos al crecimiento y los huesos de Valentina sin aumentar la probabilidad de remisión duradera en la PTI crónica. El objetivo del tratamiento de la PTI es prevenir el sangrado grave, no normalizar las plaquetas. A 28,000 sin sangrado, el riesgo del tratamiento excede el beneficio esperado. — Each steroid course adds cumulative risks to Valentina's growth and bones without increasing the probability of lasting remission in chronic ITP. The treatment goal in ITP is to prevent serious bleeding, not to normalize platelets. At 28,000 without bleeding, the treatment risk exceeds the expected benefit.
- La esplenectomía de Carlos eliminó dos cosas al mismo tiempo: el lugar donde sus glóbulos rojos esféricos se destruyen prematuramente — eso está curado — y los macrófagos de los sinusoides del bazo que filtran las bacterias encapsuladas de la sangre antes de que causen sepsis. Esa segunda función no regresa nunca porque la estructura que la realizaba ya no existe. La penicilina está reemplazando esa función, no tratando la esferocitosis hereditaria. — Carlos's splenectomy eliminated two things simultaneously: the place where his spherical red blood cells are destroyed prematurely — that is cured — and the macrophages in the splenic sinusoids that filter encapsulated bacteria from the blood before they cause sepsis. That second function never returns because the structure that performed it no longer exists. Penicillin is replacing that function, not treating the hereditary spherocytosis.
- La sepsis post-esplenectomía por neumococo puede ir de fiebre inicial a choque séptico y muerte en 12 a 24 horas con una mortalidad del 50 al 70 por ciento una vez establecida. Ese riesgo no desminuye con los años porque la arquitectura de filtrado del bazo no se regenera. Los cuatro años de buena salud de Carlos son los cuatro años que la penicilina ha estado haciendo el trabajo que su bazo ya no puede hacer. Sin la penicilina, Carlos no tiene la primera línea de defensa que los niños con bazo tienen contra esas bacterias. — Post-splenectomy sepsis from pneumococcus can go from initial fever to septic shock and death in 12 to 24 hours with 50 to 70 percent mortality once established. That risk does not diminish with years because the splenic filtration architecture is not regenerated. Carlos's four years of good health are four years that penicillin has been doing the work his spleen can no longer do. Without penicillin, Carlos does not have the first line of defense against those bacteria that children with a spleen have.
For related conditions in the pediatric hematology and oncology setting, see Spanish for pediatric sickle cell disease clinic nurses (covering annual transcranial Doppler surveillance, fever triage in functional asplenia, and pneumococcal vaccine plus prophylactic penicillin rationale), Spanish for pediatric immune thrombocytopenia clinic nurses (covering platelet transfusion inefficacy in ITP, watchful waiting threshold rationale, and thrombopoietin receptor agonist indications), and Spanish for pediatric benign hematology clinic nurses (covering ITP platelet transfusion versus IVIG, bone marrow biopsy in pancytopenia, and von Willebrand disease management).