Snakebite-associated thrombotic microangiopathy: an Australian prospective cohort study [ASP30].

Area of Science:

• Nephrology
• Hematology
• Toxicology

Background:

• Snakebite-associated thrombotic microangiopathy (TMA) is a complication of venom-induced consumption coagulopathy (VICC).
• Acute kidney injury (AKI) is the most frequent severe outcome of TMA following snakebite.
• Limited understanding exists regarding the epidemiology, diagnosis, outcomes, and treatment effectiveness for snakebite-associated TMA.

Purpose of the Study:

• To define snakebite-associated TMA using clinical and laboratory parameters.
• To investigate the incidence, clinical features, and outcomes of TMA in Australian snakebite patients.
• To evaluate the effectiveness of therapeutic plasma-exchange (TPE) in managing TMA-related AKI.

Main Methods:

• A prospective cohort study of 2069 patients with suspected or confirmed snakebite was conducted from 2004-2018.
• TMA was defined as the presence of anemia with schistocytosis.
• Data on VICC, TMA, AKI severity, dialysis requirements, and long-term renal outcomes were collected.

Main Results:

• Of 1158 systemically envenomed patients, 104 (12.4%) developed TMA, with higher incidence in taipan and brown snakebites.
• TMA patients were older and predominantly developed AKI (94%), with 34% requiring dialysis (D-AKI).
• Dialysis-free survival was high (97%) for D-AKI cases, but 52% developed stage 3 or higher chronic kidney disease (CKD) within 90 days; TPE showed no benefit.

Conclusions:

• Snakebite-associated TMA is characterized by anemia, schistocytosis, and thrombocytopenia or a significant platelet drop.
• While most patients with TMA-related AKI achieve dialysis-free survival, a substantial risk of long-term CKD exists.
• Therapeutic plasma-exchange is not effective in improving outcomes for dialysis-dependent AKI in snakebite-associated TMA.