Abstract
Background: Thrombotic microangiopathies (TMAs) is characterized by microvascular thrombosis associated with thrombocytopenia and microangiopathic hemolytic anemia (MAHA), evidenced by schistocytes in the blood. Autoimmune thrombotic thrombocytopenic purpura (TTP) is an acquired condition in which autoantibodies against ADAMTS13 leading to severe ADAMTS13 deficiency with clinical menifestation of neurologic, kidney dysfunction along with thrombocytopenia and MAHA. Multiple studies have demonstrated increased risk of acquired TTP by multiple folds in HIV infected population in the past. This study aimed to uncover current incidence and outcomes of TMA in HIV population.
Methods: This is a retrospective cohort study from TMA hospitalizations between January 1, 2016, and December 31, 2019, using the 2016-2019 National Inpatient Sample (NIS). Our study sample included TMA hospitalizations with valid information on HIV, with age 18 years or older, using the ICD 10 diagnosis codes validated in previous studies.
Results: From 2016 to 2019, a total of 5311 (weighted N =) hospitalizations with TMA hospitalizations were identified. Among them, 61.47% (n= 3264) were females, and 1.53 % (n=81) had HIV as secondary diagnosis. Mean age was 51.5 ± 17.4 years. Moreover, 49.2% of total TMA were Whites, 33.9% were Blacks, 10.3% were Hispanics, and 3.4% were Asians. The in hospital mortality for adult with TMA was 9.9% (N=525). A total of 2494(47%) hospitalizations had a Charlson Comorbidity index (CCI) of three or higher. Compared to non-HIV, those who had HIV, were similar in age (mean age: 48 vs. 52; p=0.108), were less females (45.7% vs 61.7%, p=0.004), higher incidence of Cerebro-vascular disease (24.7% vs 14.8%, p=0.018), higher mild liver disease (14.8% vs 5.5%, p=0.002), had higher CCI of three or higher (82.7% vs. 46.4%, p<0.001), but similar in-hospital mortality (7.4% vs 9.9%, p=0.574) and similar length of stay (14.7 days vs 12 days, p=0.146), had a lower annual income of $79000+ (2.6% vs 19.6%). Multivariate regression analysis showed that, compared with non-HIV, HIV had similar in-hospital mortality (aOR: 1.03; 95% CI: 0.44, 2.45; p=0.943) after controlling for age, race, gender, regional location of the hospital, income, and insurance. African Americans have lower in hospital mortality from TMA compared to whites (aOR: 0.62; 95% CI: 0.48, 0.80; p<0.001). From 2016-2019, the annual incidence of TMA per 100,000 hospitalizations has been increasing at 17 in 2016, 18 in 2017, 20 in 2018 and 20 in 2019 (p-trend<0.001).
Conclusion: There was no difference in in-hospital mortality and length of stay in TMAs with and without HIV. The annual incidence of TMA has been increasing over the years.
Disclosures
No relevant conflicts of interest to declare.
Author notes
Asterisk with author names denotes non-ASH members.
