Presentation of HIV‐Associated Thrombotic Microangiopathy and Response to Therapeutic Plasma Exchange: A 10‐year Retrospective Single‐Centre Cohort Study

ABSTRACT Background HIV is a significant aetiological factor in thrombotic microangiopathy (TMA) in regions of high seroprevalence, but description of HIV‐associated TMA (HIV‐TMA) remains limited to small case series. We sought to describe the presentation, complications of TPE, and mortality and renal outcomes of HIV‐TMA. Methods We retrospectively reviewed 98 cases of HIV‐TMA treated with therapeutic plasma exchange (TPE) between 1/1/2010 and 31/12/2020. The effect of HIV infection and clinical presentation on mortality, TPE complications, and renal outcomes were analysed using regression analysis. Results TMA is associated with advanced HIV infection (median CD4 count 151 × 106/mm 3 cells and median viral load 117500 copies/mL), usually occurs in the absence of antiretroviral therapy (ART), and shows a predilection for young Black women, reflecting TMA risk factors and local demographics of the HIV pandemic. Neurological deficit is the most common presenting feature (54.1%). HIV‐TMA mortality is high despite TPE (49% of cases); better renal function reduces risk of TMA‐attributable death (HR 0.97, 95% CI 0.96–0.99, p < 0.001); use of FFP as infusant is associated with increased risk of mortality (HR 3.96, 95% CI 1.60–9.84, p = 0.003). Sepsis frequently complicates TPE (16.3% of courses) and contributes to excess mortality (20.7% of deaths); risk of infection increases with duration of TPE (OR 1.21, 95% CI 1.07–1.37, p = 0.002), implicating augmented immunosuppression in mortality. HIV infection parameters do not significantly affect risk of mortality or sepsis. Residual renal dysfunction is relatively rare in survivors at follow‐up. Conclusion Mortality remains high in HIV‐TMA treated with TPE, and sepsis‐related complications are of concern. Randomized prospective studies are needed to evaluate the use of TPE versus plasma infusion (PI) and infusant choice in HIV‐TMA. Longer duration follow‐up studies are needed to evaluate residual renal dysfunction in survivors of HIV‐TMA.