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Hemoglobin
Hemoglobin (Hb, HbA) is the tetrameric heme protein in red blood cells carrying oxygen and CO2; key facts: cooperative binding, Bohr effect, HbF switch, sickle/thalassemia variants, HBOCs unapproved.
Hemoglobin Bart's fetalis syndrome
Hemoglobin Bart's fetalis syndrome, also called hemoglobin Bart's hydrops fetalis or alpha-thalassemia major, is the most severe form of alpha-thalassemia, caused by deletion of all four alpha globin genes and usually fatal without intrauterine transfusions.
Hemoglobin C
Hemoglobin C (HbC, HBB Glu6Lys) is a beta-globin variant causing red cell dehydration and crystals. HbAC trait is asymptomatic; HbCC causes mild anemia; HbSC is sickle cell disease with prominent retinopathy.
Hemoglobin C disease
Hemoglobin C disease (HbCC) is an autosomal recessive hemoglobinopathy from a beta-globin Glu6Lys mutation, causing mild hemolytic anemia, splenomegaly, and gallstones with normal life expectancy; distinct from HbC trait and HbSC disease.
Hemoglobin C-beta-thalassemia syndrome
Hemoglobin C-beta-thalassemia (HbC-BT, C-beta-thalassemia) is a compound heterozygous hemoglobinopathy combining HbC and a beta-thalassemia mutation, causing mild to moderate microcytic hemolytic anemia with splenomegaly, mainly in people of African descent.
Hemoglobin D disease
Hemoglobin D disease (Hb D-Punjab, Hb D-Los Angeles) is a beta-globin variant (β121 Glu→Gln, HBB c.364G>C) common in Punjab, India; benign alone, severe with Hb S.
Hemoglobin E
Hemoglobin E (HbE, Glu26Lys, HBB c.79G>A) is a common Asian beta-globin variant that is both a structural hemoglobin change and a mild beta-thalassemia mutation; HbE/β-thalassemia causes about half of severe beta thalassemia.
Hemoglobin E disease
Hemoglobin E disease (Hb EE), a benign hemoglobinopathy from a codon 26 beta-globin mutation common in Southeast Asia; trait is asymptomatic, but Hb E/beta-thalassemia causes about half of severe beta-thalassemia worldwide.
Hemoglobin E-beta-thalassemia syndrome
Hemoglobin E-beta-thalassemia (HbE-BT, E-beta-thalassemia) is an autosomal recessive beta-thalassemia of compound heterozygotes for HbE and beta-thalassemia, predominant in Southeast Asia, ranging from mild intermedia-like anemia to thalassemia major.
Hemoglobin electrophoresis
Hemoglobin electrophoresis is a blood test that separates and measures hemoglobin types (HbA, HbA2, HbF, HbS, HbC, HbE) by electric charge to diagnose sickle cell disease, thalassemia, and other hemoglobinopathies.
Hemoglobin H disease
Hemoglobin H disease (HbH disease, alpha-thalassemia intermedia): inherited anemia from inactivation of three of four alpha-globin genes; excess beta chains form unstable HbH tetramers; non-deletional forms are more severe.
Hemoglobin M disease
Hemoglobin M disease (M hemoglobinopathy; methemoglobinemia, beta type) is an autosomal dominant congenital methemoglobinemia from His-to-Tyr globin variants (Hb M-Boston, M-Iwate, M-Saskatoon, M-Milwaukee) causing benign lifelong cyanosis needing no treatment.
Hemoglobin variants
Hemoglobin variants, also called Hb variants, are abnormal forms of hemoglobin produced by globin gene mutations; more than 1000 are known, some causing erythrocytosis or cyanosis.
Hemoglobin, beta-type
Hemoglobin, beta-type (beta-globin, HBB gene, 11p15.4) is the beta chain of the α2β2 hemoglobin tetramer, one of the developmentally regulated beta-like globin genes; mutations cause sickle cell disease and beta-thalassemia.
Hemoglobinometry
Hemoglobinometry (haemoglobinometry): measurement of blood hemoglobin concentration to screen and diagnose anemia. Cyanmethemoglobin method and automated analyzers are reference standards; HemoCue dominates point-of-care field testing; WHO 2024 guidance favors venous blood.
Hemolymph
Hemolymph (haemolymph) is the blood-analogous circulatory fluid of mollusks, arthropods, and insects in open circulatory systems, combining blood and lymph roles, carrying hemocytes and often copper-based hemocyanin rather than red-cell hemoglobin.
Hemolysis
Hemolysis is premature red blood cell destruction with hemoglobin release, causing hemolytic anemia; covers intravascular vs extravascular mechanisms, lab markers (haptoglobin, LDH, DAT), hereditary and immune causes, complement inhibitors, and 2023 sickle cell gene therapies.
Hemolysis (microbiology)
Hemolysis in microbiology: bacterial lysis of red blood cells on blood agar, read as alpha (partial, green), beta (complete, clear), or gamma (none) patterns caused by hemolysins used to identify streptococci, staphylococci, and other pathogens.
Hemolysis assay
A hemolysis assay is a bench biology method that measures rupture of red blood cells by spectrophotometrically detecting the hemoglobin they release, reporting membrane damage as a hemolysis percentage.
Hemolytic anemia
Hemolytic anemia: premature red blood cell destruction (normal lifespan ~120 days) outpacing marrow production. Covers extravascular vs intravascular hemolysis, Coombs/DAT classification, warm/cold AIHA, G6PD deficiency, sickle cell, hereditary spherocytosis, and treatments including steroids, rituximab, eculizumab, and sutimlimab.
Hemolytic anemia due to glucophosphate isomerase deficiency
Hemolytic anemia due to glucophosphate isomerase deficiency, also known as GPI deficiency, is a rare inherited anemia beginning in infancy, caused by a faulty glycolytic enzyme.
Hemolytic anemia due to pyrimidine 5' nucleotidase deficiency
Hemolytic anemia due to pyrimidine 5' nucleotidase deficiency (P5N deficiency, UMPH1 deficiency, CNSHA8, OMIM 266120): rare autosomal recessive NT5C3A red cell enzymopathy with mild-moderate hemolytic anemia, basophilic stippling, and erythrocyte pyrimidine nucleotide accumulation; also mimicked by lead poisoning.
Hemolytic anemia from infection and toxins
Hemolytic anemia from infection and toxins is the accelerated destruction of red blood cells caused by infectious organisms, notably malaria, or by toxins including snake venom, copper, and lead.
Hemolytic disease of the newborn
Hemolytic disease of the newborn (HDFN, erythroblastosis fetalis): maternal IgG antibodies cross the placenta and destroy fetal red cells, mainly from RhD or ABO incompatibility; prevented by anti-D immunoglobulin, treated with phototherapy and transfusion.
Hemolytic disease of the newborn (ABO)
ABO hemolytic disease of the newborn (ABO HDN, ABO HDFN): neonatal hemolysis from maternal anti-A/anti-B IgG, almost always group O mother with A or B infant; usually mild jaundice treated with phototherapy.
Hemolytic Plaque Technique
Hemolytic plaque technique (Jerne plaque assay, plaque-forming cell assay): 1963 Jerne and Nordin method counting single antibody-secreting cells by complement lysis of sheep red blood cells in agar; predecessor of ELISPOT.
Hemolytic–uremic syndrome
Hemolytic–uremic syndrome (HUS), also called atypical HUS (aHUS) in its complement-mediated form, is a thrombotic microangiopathy with thrombocytopenia, hemolytic anemia, and kidney injury; STEC-HUS follows Shiga toxin E. coli, aHUS follows complement dysregulation treated with eculizumab or ravulizumab.
HEMOPEC trial
HEMOPEC (NCT07070973) is a pilot trial at Gemelli in Rome testing AI-guided Assisted Fluid Management and Hypotension Prediction Index against goal-directed therapy during cytoreductive surgery with HIPEC for ovarian cancer, 52 women, 2025-2027.
Hemoperfusion
Hemoperfusion is an extracorporeal treatment that passes anticoagulated blood through a column of activated charcoal or resin beads to remove poisons, toxins, and inflammatory mediators.
Hemopericardium
Hemopericardium, or hemorrhagic pericardial effusion, is blood accumulating in the pericardial sac, risking cardiac tamponade. Leading causes: invasive cardiac procedures (~31%), aortic dissection, trauma, malignancy, infection, anticoagulants; diagnosed by echocardiography and high-attenuation CT fluid.