Massive intravascular haemolysis with T‐activation and disseminated intravascular coagulation due to clostridial sepsis

Abstract

An 80-year-old man presented to the emergency department with acute onset of rigors, dyspnoea and delirium, after 2 d of abdominal pain. He had a past history of cholecystectomy and type II diabetes mellitus. On arrival he was febrile and jaundiced with a tender abdomen. Spun blood samples revealed bright red plasma consistent with intravascular haemolysis (top left). The total haemoglobin was 8.7 g/dl, of which 6.7 g/dl was free plasma haemoglobin. The blood film demonstrated severe anaemia with microspherocytes and red cell fragments, toxic vacuolation, phagocytosed bacilli and marked thrombocytopenia (top right). Coagulation studies were consistent with disseminated intravascular coagulation (DIC). The results of a lectin panel were consistent with red cell T-activation. The source of sepsis was demonstrated by an abdominal computed tomography scan, which showed a gascontaining liver abscess with pneumobilia (bottom). Together these findings were characteristic of clostridial sepsis with massive intravascular haemolysis. In this case, despite recognition of the diagnosis on presentation, the patient did not respond to aggressive directed therapy and died within 3 h of admission. Blood cultures later revealed Clostridium perfringens. In adults, clostridial sepsis typically occurs in patients with gastrointestinal or genitourinary abscesses or following recent abdominal surgery. The patients often have an underlying malignancy or diabetes mellitus. Although infrequent, massive intravascular haemolysis is a classic complication of clostridial sepsis. It has a high mortality rate, despite prompt treatment with appropriate antibiotic and supportive therapy. Intravascular haemolysis results from the enzymes produced by Clostridia species. Alpha-lecithinase directly causes red cell membrane disruption and is likely to be the most significant cause of haemolysis. Neuraminidase acts on red cell membranes, cleaving off N-acetyl-neuraminic acid to expose the normally hidden T-cryptantigen (T-activation). Exposed T-antigen is then the target of anti-T, a naturally occurring haemolytic antibody present in all adult plasma. However, the contribution of T-activation to haemolysis is likely to be minor. In addition to the effects of clostridial enzymes, microangiopathy from associated DIC may contribute to intravascular haemolysis.