PA H6 | Aplastic Anemia & Bone Marrow Failure — Glossary

A syndrome of pancytopenia caused by failure of the bone marrow to produce blood cells, characterised by hypocellular marrow devoid of abnormal cells, fibrosis, or infiltration.

A sample of liquid marrow withdrawn by syringe; used to assess individual cell morphology, perform cytochemistry, immunophenotyping, and cytogenetics.

Severity classification for aplastic anaemia based on peripheral blood counts and marrow cellularity; distinguishes non-severe, severe (SAA), and very severe (vSAA) disease to guide treatment decisions.

A broad-spectrum antibiotic associated with two forms of marrow toxicity: predictable dose-dependent suppression and rare idiosyncratic aplastic anaemia that is irreversible.

An activated CD8+ T cell that destroys haematopoietic stem cells in immune-mediated aplastic anaemia via Fas–FasL signalling, perforin/granzyme release, and pro-inflammatory cytokines.

Failure to obtain marrow by aspiration despite correct needle placement, indicating either marrow fibrosis (as in myelofibrosis) or tightly packed cellular infiltration.

An inherited marrow failure syndrome caused by telomerase gene mutations, characterised by the clinical triad of nail dystrophy, oral leucoplakia, and abnormal skin pigmentation.

An autosomal recessive inherited marrow failure syndrome caused by defects in DNA repair genes (FANC family), presenting with physical anomalies (absent thumbs, café-au-lait spots) and a high risk of leukaemia.

A CD34+ multipotent progenitor cell in the bone marrow capable of self-renewal and differentiation into all blood cell lineages.

A subtype of myelodysplastic syndrome with reduced marrow cellularity that closely mimics aplastic anaemia; differentiated by the presence of dysplastic cells and cytogenetic abnormalities.

Aplastic anaemia for which no causative agent or inherited defect is identified, accounting for approximately 70% of cases and presumed autoimmune in mechanism.

The proportion of the bone marrow space occupied by haematopoietic cells versus fat cells; normally approximated as 100 minus the patient's age (in percentage terms).

The ratio of myeloid (granulocytic) to erythroid precursors assessed on a bone marrow aspirate; normally 3:1 to 4:1 in adults.

Simultaneous reduction in red blood cells, white blood cells (particularly neutrophils), and platelets in the peripheral blood.

The preferred site for bone marrow aspiration and trephine biopsy in adults; safe, accessible, and contains abundant marrow away from vital structures.

Selective absence of erythroid precursors in an otherwise normal marrow, as caused by Parvovirus B19; distinct from aplastic anaemia which affects all cell lines.

An increase in the proportion of lymphocytes in the differential count seen in aplastic anaemia, because lymphocytes are mature cells not stem-cell–dependent and are relatively preserved when granulopoiesis and erythropoiesis fail.

Abnormally low reticulocyte count, indicating failure of new red cell production by the bone marrow; a key finding distinguishing aplasia from haemolysis.

A hepatitis syndrome negative for hepatitis A, B, and C serological markers; strongly associated with subsequent severe aplastic anaemia, especially in young males.

Removal of an intact core of bone and marrow tissue using a hollow Jamshidi needle; provides histological assessment of marrow architecture and cellularity.