Haematology Vignettes – 12

Clostridium perfringens induced haemolytic anaemia

A 56-year-old female presents with a perforated bowel secondary to metastatic ovarian cancer. She has acute abdominal pain and is passing dark-red urine.

A FBC is performed with the following results:

Hb 75 g/L, WBC 14.3 x 109/L and Platelet count 163 x 109/L

The blood film shows the presence of a marked number of micro spherocytes.

The following Clinical Chemistry tests are performed:

LDH 1936 IU/L NR 90-200
 Urea  11.1  mmol/L  NR 2.9-7.1
 Creatinine  206  umol/L  NR 60-110
 Bilirubin total  507  umol/L  NR 0-25
 ALP  48  U/L  NR 38-126
 GGT  10   U/L  NR 0-30
 AST  2550   U/L  NR <45
 ALT  590   U/L  NR <45

A diagnosis of haemolytic anaemia secondary to Clostridium perfringens infection is made.

Clostridium perfringens

Peripheral blood film showing a marked number of micro spherocytes

Peripheral blood film showing a marked number of micro spherocytes

Clostridium perfringens is an anaerobic Gram-positive bacillus associated with 3 distinct disease states, namely, gas gangrene or clostridial myonecrosis, enteritis necroticans and clostridium food poisoning. Clostridium perfringens is a saprophytic organism inhabiting the bowel and genital tract. It has no pathophysiological significance in the absence of clinical infection.

Clostridium perfringens produces at least 12 antigenic protein toxins, the most common of which is the alpha toxin. These toxins react with lipoprotein complexes on cell surfaces, liberating potent haemolytic substances known as lysolecithins resulting in cell lysis. This process leads to a haemolytic anaemia, which may be so severe, the end result is death. During this process of cell lysis, large amounts of CO2 and hydrogen are produced. This leads to intense abdominal swelling hence the term gas gangrene. A foul-smelling odour is given off from the necrotic tissue.

When a patient presents with bowel perforation, clostridia are released into the surrounding tissues, giving rise to tissue necrosis. This process is a rapid one proceeding up to 10cm per hour. The patient develops severe haemolytic anaemia. Haemoglobinemia and haemoglobinuria occur. The serum becomes a brilliant red colour resulting in dissociation between the haemoglobin and the haematocrit level. A leucocytosis with a left shift as well as a thrombocytopenia is present. Acute renal and hepatic failure develops leading to death in as short a period as 12 hours if not treated immediately.

There is no specific treatment available for Clostridium perfringens. The basis of treatment is surgical debridement of necrotic tissue and antibiotic therapy. In severe infections, hyperbaric oxygen is an important adjunct if available. Massive doses of benzylpenicillin are administered intravenously in cases of clostridial sepsis. Should the patient be allergic to penicillin, metronidazole is effective in high doses.

The above patient died 48 hours post admission to hospital.