Clinical Experience of Therapeutic Plasma Exchange (TPE) in Severe Leptospirosis: A Case Series from Sri Lanka.

Leptospirosis is a globally prevalent zoonosis with significant morbidity and mortality, especially in tropical regions like South Asia. In its severe form, the disease often leads to multiorgan dysfunction, with pulmonary haemorrhage being a major cause of death. Evidence supporting specific treatments for severe leptospirosis with pulmonary involvement remains limited. Recent studies suggest that immunomodulatory therapies, such as therapeutic plasma exchange (TPE), may offer survival benefits. This case series explores the application and outcomes of TPE in patients with severe leptospirosis at a tertiary care hospital in Sri Lanka. We studied a case series involving nine patients with confirmed severe leptospirosis and multiorgan involvement from September 2021 to October 2022. All patients received standard care, including intravenous antibiotics and methylprednisolone. TPE was initiated in all nine patients based on clinical severity, particularly in the presence of pulmonary haemorrhage. Clinical, laboratory, and radiological data were collected from patient records and follow-up. Leptospirosis diagnosis was confirmed through ELISA IgM testing. TPE decisions were made by a multidisciplinary team. Of the nine patients who received TPE, seven survived (78%). Pulmonary haemorrhage was the primary indication for TPE in all cases. All patients had multiorgan involvement: renal failure (89%), hepatic dysfunction (55%), and myocarditis (67%). Mortality was associated with inotropic-dependent myocarditis and mechanical ventilation at TPE initiation. Patients requiring intubation had a 50% mortality rate, compared to 14% in those who were not intubated. Non-survivors also had significantly elevated lactate levels (>4 mmol/L) and worsening acid-base status. Four patients required dialysis: three survived. Early initiation of TPE may be safe and beneficial in severe leptospirosis, and future randomised controlled studies are necessary to examine its benefits further. These findings are hypothesis-generating for further research, particularly on patient selection for TPE.