IM9.1-17 | Anaemia — Glossary

The most dangerous transfusion reaction; typically caused by ABO incompatibility from patient identification error; presents within minutes with fever, rigors, loin or back pain, haemoglobinuria, and haemodynamic collapse; treatment is immediate cessation of transfusion, supportive care, and investigation; potentially fatal from DIC and AKI.

A reduction in haemoglobin concentration below WHO thresholds: <13.0 g/dL in adult males, <12.0 g/dL in non-pregnant women, <11.0 g/dL in pregnant women; results in reduced oxygen-carrying capacity.

India's national strategy launched in 2018 to reduce anaemia across all life stages; part of POSHAN Abhiyaan; uses a 6×6×6 framework targeting six population groups through six interventions at six institutional platforms; includes WIFS, antenatal IFA, deworming, and dietary behaviour change.

Also called anaemia of inflammation; normocytic (occasionally microcytic) anaemia associated with chronic infection, inflammation, or malignancy; caused by hepcidin-mediated iron sequestration in macrophages; ferritin is normal or elevated, TIBC is normal or low.

Cracking, erythema, and maceration at the corners of the mouth; a mucocutaneous sign of iron deficiency anaemia and B12/folate deficiency; may also be caused by Candida infection, especially if immunocompromised.

A soft mid-systolic murmur at the cardiac apex caused by turbulent, high-velocity blood flow through a normal mitral orifice in the hyperdynamic circulation of significant anaemia; not a structural lesion; disappears with correction of anaemia.

Pancytopenia caused by bone marrow failure; most commonly acquired and autoimmune (T-cell-mediated destruction of haematopoietic stem cells); hypocellular marrow on biopsy; treatment is allogeneic haematopoietic stem cell transplant or immunosuppressive therapy.

Autosomal recessive reduction or absence of β-globin chain synthesis; trait (minor) is asymptomatic with mild microcytosis and elevated HbA2 >3.5% on HPLC; major (Cooley's anaemia) causes transfusion-dependent haemolytic anaemia from infancy; India has the world's largest thalassaemia burden.

Sampling of bone marrow cells from the posterior superior iliac spine by aspiration needle; used to examine marrow cellularity, erythroid and myeloid maturation, and abnormal cell populations; essential for diagnosis of aplastic anaemia, haematological malignancy, MDS, and sideroblastic anaemia.

Pallor of the palpebral conjunctiva (lower eyelid everted) reflecting reduced haemoglobin in the subepithelial capillaries; the most sensitive and reproducible examination sign for anaemia; sensitivity ~85–90% for Hb <9 g/dL.

A blood component prepared from FFP by cold precipitation; rich in fibrinogen, Factor VIII, von Willebrand factor, and Factor XIII; used for hypofibrinogenaemia with active bleeding, haemophilia A, and von Willebrand disease where recombinant factors are unavailable.

Synthetic forms of vitamin B12 used for parenteral replacement of B12 deficiency; hydroxocobalamin is preferred in the UK (longer half-life); standard loading regimen: 1000 µg IM daily for 7 days, then weekly for 4 weeks, then monthly for life in absorptive failure (pernicious anaemia, gastrectomy).

A test that detects IgG antibodies or complement (C3d) bound to the surface of red blood cells in vivo; positive in autoimmune haemolytic anaemia (warm and cold AIHA), drug-induced haemolysis, and haemolytic disease of the newborn.

Direct Antiglobulin Test; detects IgG antibody or complement deposited on the surface of the patient's red cells; positive in autoimmune haemolytic anaemia (AIHA); a negative DAT directs toward non-immune haemolytic causes.

The actual iron content available for absorption from an oral iron supplement; ferrous sulphate 200 mg provides approximately 65 mg elemental iron; ferrous gluconate and ferrous fumarate provide less per tablet; the standard treatment dose is 150–200 mg elemental iron per day.

Recombinant human erythropoietin (epoetin alfa or darbepoetin alfa) used to stimulate red cell production in anaemia of CKD and other hypoproliferative states; target Hb 10–11.5 g/dL per KDIGO guidelines; avoid Hb >13 g/dL (associated with cardiovascular events); requires concurrent iron supplementation.

The most common transfusion adverse reaction; temperature rise >1°C with chills during or within 4 hours of transfusion; caused by cytokines in stored blood or anti-leukocyte antibodies; managed with paracetamol and slowing the infusion; leucodepleted blood products reduce recurrence.

The primary iron storage protein; serum ferritin reflects total body iron stores; low ferritin (<15–20 µg/L) is the most specific single test for iron deficiency; elevated ferritin in ACD (acute-phase reactant) can mask concurrent IDA.

The only known cellular iron export channel, expressed on duodenal enterocytes, macrophages, and hepatocytes; targeted by hepcidin for degradation; its inhibition traps iron inside cells, causing anaemia of chronic disease.

The standard oral iron supplement for treatment of iron deficiency anaemia; one tablet of 200 mg contains approximately 65 mg of elemental iron; taken on an empty stomach with vitamin C to maximise absorption; causes dark stools and constipation as common side effects.

Periconceptional folic acid (400 µg/day for low-risk women; 5 mg/day for women with prior NTD-affected pregnancy) prevents neural tube defects; treatment of folate deficiency: 5 mg/day for 4 months; must NEVER be given alone without excluding B12 deficiency, as it corrects haematological abnormalities while allowing neurological B12 deficiency to progress.

A blood component containing all clotting factors, prepared from whole blood or apheresis and frozen within 8 hours; used for coagulopathy with active bleeding, DIC, reversal of warfarin toxicity, TTP (plasma exchange), and liver disease factor deficiency; not indicated for volume replacement alone.

X-linked recessive deficiency of glucose-6-phosphate dehydrogenase, the enzyme generating NADPH in the hexose monophosphate shunt; NADPH is the primary antioxidant defence of RBCs; oxidative stress (drugs — primaquine, dapsone; infections; fava beans) triggers acute haemolysis and Heinz body formation.

Formula for calculating total parenteral iron dose: Total iron deficit (mg) = body weight (kg) × (target Hb − actual Hb) × 2.4 + 500 mg (for storage iron); used to guide total IV iron replacement in iron deficiency anaemia.

Inflammation and atrophy of the tongue; in IDA produces a smooth, pale, atrophic tongue with loss of filiform papillae; in B12 deficiency produces a smooth, beef-red, painful tongue; in both conditions associated with angular stomatitis.

The presence of free haemoglobin in the urine, producing dark red-brown ('Coca-Cola') discolouration; occurs in intravascular haemolysis when free haemoglobin in plasma exceeds the renal tubular reabsorptive capacity; indicates severe acute haemolysis.

A 25-amino-acid peptide hormone secreted by the liver in response to inflammation (IL-6) and iron loading; binds to ferroportin causing its degradation, thereby blocking intestinal iron absorption and macrophage iron release; the master regulator of iron homeostasis and key mediator of ACD.

Autosomal dominant disorder of RBC membrane proteins (spectrin, ankyrin, band 3); produces spherical erythrocytes that are destroyed in the spleen; diagnosed by peripheral film (spherocytes + reticulocytosis) and EMA binding test; treated by splenectomy in severe cases.

Infection with Ancylostoma duodenale (common in India) acquired by percutaneous penetration of larval-stage hookworms through bare feet; adults attach to small intestinal mucosa and cause chronic blood loss (2–5 mL per 100 worms per day), a major preventable cause of IDA in rural India.

The compensatory cardiovascular state in moderate-to-severe anaemia: tachycardia, bounding pulses, wide pulse pressure, raised JVP, apical systolic flow murmur, and cardiomegaly in chronic severe cases; results from increased cardiac output driven by tissue hypoxia.

A neutrophil with ≥5 lobes in ≥5% of neutrophils, or any neutrophil with ≥6 lobes; the most sensitive peripheral blood film marker of megaloblastic haematopoiesis; caused by B12 or folate deficiency.

The most common nutritional deficiency globally; caused by inadequate intake, increased demand, chronic blood loss, or malabsorption; characterised by microcytic hypochromic RBCs, high RDW, low ferritin (<15–20 µg/L), high TIBC, and pencil cells on film.

Spoon-shaped (concave) deformity of the fingernails, most prominent in the index and ring fingers; a clinical sign of chronic severe iron deficiency anaemia; reflects brittle, soft nails that deform under pressure.

The average volume of a red blood cell in femtolitres (fL); calculated as haematocrit ÷ RBC count × 10; normal range 80–100 fL; forms the primary axis of morphological anaemia classification.

Anaemia caused by impaired DNA synthesis due to B12 or folate deficiency; characterised by macro-ovalocytes, hypersegmented neutrophils, MCV >100 fL; B12 deficiency additionally causes subacute combined degeneration of the spinal cord.

Black, tarry, foul-smelling stools caused by digestion of blood from an upper GI source (proximal to the ligament of Treitz); indicates significant upper GI bleeding (haematemesis source or rapid small intestinal bleeding); must not be dismissed as haemorrhoids in any adult.

MCV ÷ RBC count; a ratio used to screen for thalassaemia trait vs IDA in microcytic anaemia: index >13 suggests IDA; index <13 suggests thalassaemia trait; a useful bedside discriminator but not definitive.

A metabolic intermediate whose conversion to succinyl-CoA requires vitamin B12 (adenosylcobalamin); elevated serum MMA is specific to B12 deficiency and distinguishes it from folate deficiency (folate does not affect MMA metabolism).

Mechanical fragmentation of red blood cells in narrowed or thrombosed small vessels; produces schistocytes and helmet cells on peripheral blood film; causes include TTP, HUS, DIC, malignant hypertension, and HELLP syndrome.

The standard blood component for treatment of anaemia; each unit contains approximately 200–250 mL of red cells in additive solution with haematocrit 55–65%; expected haemoglobin rise of 1–1.5 g/dL per unit in a 70 kg adult; stored at 2–6°C for up to 35–42 days.

Simultaneous reduction of all three peripheral blood cell lines — red cells (anaemia), white cells (leucopenia), and platelets (thrombocytopenia); clinically manifest as pallor + increased susceptibility to bleeding (purpura, petechiae) + increased infections; indicates bone marrow failure or infiltration.

Intravenous iron preparation used when oral iron is not tolerated or absorbed, or when rapid repletion is required; formulations include iron sucrose, ferric carboxymaltose (allows large single doses), and low-molecular-weight iron dextran; total dose calculated by Ganzoni formula; risk of anaphylaxis requires test dose and resuscitation readiness.

Elongated, thin red cells on peripheral smear, characteristic of iron deficiency anaemia; arise because iron-deprived red cells lose haemoglobin content and become deformed during passage through the microcirculation.

Autoimmune atrophic gastritis causing destruction of gastric parietal cells and failure of intrinsic factor secretion; the most common autoimmune cause of B12 deficiency; associated with anti-parietal cell antibodies (90%) and anti-intrinsic factor antibodies (50–70%).

The compulsive craving for and ingestion of non-food substances (clay, mud, ice, chalk, paper); pathognomonic of iron deficiency anaemia; culturally recognised in India as 'mitti khana'; must be specifically asked about as patients rarely volunteer it.

A standardised validated tool for quantifying menstrual blood loss by charting pad/tampon soiling patterns and clot sizes; a PBAC score >100 correlates with measured blood loss >80 mL (heavy menstrual bleeding); used clinically to objectify menorrhagia.

A triad of dysphagia (from a post-cricoid oesophageal web), iron deficiency anaemia, and glossitis; seen in middle-aged women; clinically important because of an association with hypopharyngeal and oesophageal carcinoma.

Bluish-grey tinge to red cells on peripheral smear due to residual RNA in prematurely released reticulocytes; a visual marker of reticulocytosis, indicating active marrow response to haemolysis or haemorrhage.

A measure of anisocytosis (variation in RBC size); normal <14.5%; elevated in iron deficiency anaemia (early, sensitive marker) and normal in thalassaemia trait — key discriminator.

An evidence-based approach to blood transfusion that uses a lower haemoglobin threshold (Hb <7 g/dL for stable non-cardiac patients; <8 g/dL for cardiovascular disease) rather than transfusing to achieve a normal haemoglobin; supported by TRICC and FOCUS trials; reduces unnecessary transfusion exposure and its associated risks.

Corrected reticulocyte count adjusted for the degree of anaemia: RI = reticulocyte% × (patient haematocrit ÷ 45); RI >2.5 = hyperproliferative (haemolysis/blood loss); RI <2.0 = hypoproliferative (nutritional/aplastic/renal).

A corrected reticulocyte count that adjusts for the degree of anaemia and premature reticulocyte release; RPI <2 indicates hypoproliferative anaemia (marrow failing to respond adequately); RPI ≥2 indicates hyperproliferative anaemia (marrow compensating, as in haemolysis or blood loss).

Erythroblasts with ≥5 iron-laden mitochondrial granules visible on Prussian blue stain, arranged in a ring encircling ≥1/3 of the nucleus; pathognomonic of sideroblastic anaemia; represent defective haem synthesis causing mitochondrial iron overload.

Red cell fragments including helmet cells and triangle cells on peripheral smear; pathognomonic of microangiopathic haemolytic anaemia (MAHA) caused by mechanical red cell destruction in TTP, HUS, DIC, or malignant hypertension.

The most clinically useful single marker of iron stores; ferritin <30 ng/mL is highly specific for iron deficiency; however, ferritin is an acute-phase reactant and can be falsely normal or elevated in infection, inflammation, liver disease, or malignancy, masking concurrent iron deficiency.

A plasma protein that binds free haemoglobin released during intravascular haemolysis; consumed and falls to undetectable levels in intravascular haemolysis; the most sensitive single marker of intravascular haemolysis.

Autosomal recessive haemolytic anaemia caused by a point mutation in β-globin (Glu→Val at position 6), producing HbS that polymerises under deoxygenation; causes haemolytic anaemia, vaso-occlusive crises, and organ damage; prevalent in tribal populations of central India.

A small, round, densely staining red cell lacking central pallor; seen in hereditary spherocytosis (numerous and uniform) and autoimmune haemolytic anaemia; associated with elevated MCHC; arises from membrane loss with retained haemoglobin content.

Demyelination of the dorsal and lateral columns of the spinal cord caused by B12 (not folate) deficiency; presents with sensory ataxia, Romberg sign, vibration/proprioception loss, and upper motor neurone signs; can occur without significant anaemia.

Neurological complication of severe B12 deficiency affecting the posterior (dorsal columns) and lateral (corticospinal) spinal cord tracts; presents with loss of proprioception, vibration sense, sensory ataxia, Lhermitte's sign, and progressive paraparesis; partially or incompletely reversible with B12 treatment; occurs if folic acid is given without correcting B12 deficiency.

Pulmonary oedema and respiratory distress from volume overload during blood transfusion; risk highest in elderly, CKD, and heart failure patients; prevented by slow infusion rate and diuretic use between units; treated with frusemide and supplemental oxygen.

Red cells with a central dense area surrounded by a pale ring and a dense periphery (shooting-target appearance); seen in thalassaemia, liver disease, and post-splenectomy states; arise from excess membrane relative to haemoglobin content.

A proxy measurement of serum transferrin concentration; elevated in IDA (compensatory increase in transferrin to scavenge more iron) and reduced in ACD (transferrin synthesis suppressed by IL-6); used alongside ferritin and TSAT to distinguish IDA from ACD.

Acute respiratory distress syndrome occurring within 6 hours of transfusion; caused by donor anti-HLA or anti-neutrophil antibodies activating recipient neutrophils in pulmonary vasculature; non-cardiogenic pulmonary oedema on CXR; managed with supportive oxygen and ventilation if needed; usually resolves within 96 hours.

Calculated as (serum iron ÷ TIBC) × 100; normal range 20–45%; TSAT <16% indicates iron-restricted erythropoiesis, seen in both IDA and functional iron deficiency in ACD.

A component of Anaemia Mukt Bharat for adolescents aged 10–19 years; delivers weekly IFA tablets containing 100 mg elemental iron plus 500 µg folic acid, year-round through schools and AWC with supervised consumption; co-administered with biannual albendazole 400 mg deworming.