A case of paroxysmal cold haemoglobinuria following chickenpox.

Investigations showed a very low Hb of 2.3 g/dl, platelet count of 3.89 x 109/l, and white cell count of 11.8 x 109/l (neutrophils 85%). Blood picture showed cold type HA, but failed to show any erythro-phagocytic neutrophils. She had a high ESR (125mm/hr) and high ferritin (312 nmol/l [ref. 0.27 0.337 nmol/l]) levels. Serum iron was 178 μmol/l, TIBC was 240 μmol/l and transferrin saturation was 74%. Liver function tests showed increased serum bilirubin levels (total 25.6 mmol/l, direct 5.2 mmol/l) with normal enzyme levels. She had normal abdominal ultra sonography. Renal function tests, urine analysis and culture were normal. Direct Coomb’s test was weakly positive with poly-specific anti-human globulin, and the indirect test was negative. Cold agglutinins were negative after screening at 4 oC against adult (I), cord (i) and autologous erythrocytes. Donath-Landsteiner antibody was positive, confirming the diagnosis. However, anti-P antigen specificity was not tested. Mycoplasma antibodies, HIV screening, VDRL, hepatitis B antibodies, Rheumatoid Factor and Anti Nuclear Antibodies were negative. G6PD assay, Epstein-Barr serology and osmotic fragility were not performed.