LAUSR

Aim Antibodies against the angiotensin II type 1 receptor (AT1R-Abs) have been implicated in a number of disease processes, including development of fibrosis in cystic fibrosis and systemic sclerosis, antibody mediated rejection in solid organ transplantation and more recently frailty in an aging population. AT1R-Abs were originally isolated in women with preeclampsia characterized by development of hypertension during pregnancy. Hemolysis, elevated liver enzymes, and low platelets (HELLP) syndrome has been recognized as a complication of preeclampsia in pregnant women. Diagnostic tools are needed to distinguish women who develop HELLP syndrome from preeclampsia. In this study we determined the prevalence of AT1R-Ab in patients with HELLP syndrome. Methods Sera from 45 women (11 controls defined as having normal pregnancies, 19 HELLP or partial HELLP, 15 preeclampsia) were tested for presence of AT1R-Ab. The average gestational age was 31.9 weeks. The group included 21 Caucasian, 19 African American and 5 non-Caucasian, non-African American women. AT1R-Ab testing was performed using quantitative ELISA (One Lambda, ThermoFisher). A concentration >17 Units/ml was considered positive for AT1R-Ab. Results Three of the 19 HELLP patients (16%) and 1 of the 15 preeclampsia patients (6%) were positive for AT1R-Ab. None of the patients in the control group had AT1R-Ab >17 Units/ml. Overall, there was no significant difference in the mean AT1R-Ab concentration between the control group and the diseased group (preeclampsia and HELLP; 11.39 Units/ml versus 9.48 Units/ml respectively; p = 0.2). Conclusions In this small study, we did not find a significant difference in the concentration of AT1R-Ab in the disease population compared to the control group. Interestingly, while none of the patients in the control group had concentrations >17 Units/ml, 4 patients in the diseased group had strong antibody. A larger patient population may be needed to determine significance. Evaluation of the AT1R-Ab ELISA for detection of AT1R-Ab in populations other transplant patients can be beneficial.