Beware Of Temperature Changes: A Case Report Of Paroxysmal Cold Haemoglobinuria

Paroxysmal cold haemoglobinuria is an immune haemolytic syndrome characterized by the presence of autoantibodies reactive against specific red blood cell antigens. At low temperatures, these antibodies and the complement fix to the red blood cells, leading to haemolysis upon warming up. We present the case of a twenty-one months old male child, who presented with a six-day history of malaise, productive cough and fe -ver, already medicated with amoxicillin and clavulanic acid two days before. On physical examination, the child was prostrated, severe ly pale, but with no hemodynamic instability or difficulty breathing. Blood tests revealed the presence of severe anaemia (Hb 5.4 g/dL), leucocytosis (19.90 x 10 9 /L), without immature cells in the blood film; reticulocytosis (89.7 x 10 6 /L) and evidence of hemolysis (haptoglo-bin <8 mg/dL; LDH 1328 UI/L; bilirubin 1 mg/dL and unconjugated bilirubin 0.6 mg/dL), C-reactive-protein 56.7 mg/L. He received a transfusion of red blood cells, initiated treatment with oral clarithro mycin and reinforced the rewarming of the extremities with good re - sults (Hb 9.6 g/dL). Regarding serological investigation, the results revealed a positive IgM for Mycoplasma pneumoniae ; positive Direct Antiglobulin Test with specificity for CD3, and positive Donath Land steiner test, leading to the diagnosis. This case report represents a syndrome that even though rare, is important to bear in mind when facing a case of severe haemolysis. Despite the favorable outcome, additional follow-up must be placed in outpatient setting, with periodic clinical and laboratorial revalua -tions.