Plasma exchange with immunosuppression in pulmonary alveolar haemorrhage due to leptospirosis.

ABSTRACT

Background & objectives: Pulmonary involvement due to leptospirosis carries high case fatality rate and is the commonest cause of death due to leptospirosis. Immune mechanisms play a key role in the pathogenesis of leptospiral pulmonary haemorrhage. As other immune pulmonary haemorrhages due to non leptospiral causes are treated with plasma exchange and cyclophosphamide we evaluated their efficacy in patient with leptospiral pulmonary haemorrhage. Methods: Of the 602 confirmed patients of leptospirosis, 236 (39.2%) had pulmonary haemorrhage. Of these,144 had mild haemorrhage (acute lung injury score < 2.5) and were included in the study. One hundred and fourteen patients were given two cycles of plasma exchange, 24 h apart, 25 ml/kg body weight of plasma was removed in each cycle. Cyclophosphamide (20 mg/kg body weight) was given after the first plasma exchange cycle. The remaining 30 patients were not given this treatment, and used as control. Results: In the control group only 5 (16.6%) patients survived while in the treatment group 70 (61.40%) patients survived. Thrombocytopenia was observed in 111 (77.08%) patients. Renal and hepatic involvement was seen but did not account for mortality. Minor complications were seen in group I patients after plasma exchange and cyclophosphamide treatment, but none were serious. Interpretation & conclusions: Our findings showed that plasma exchange with immunosuppression improved survival in patients of pulmonary alveolar haemorrhage due to leptospirosis, suggesting that immune mechanisms play a key role in the pathogenesis of the disease.