The loss of retinal pericytes (RPCs) is a hallmark of early stage diabetic retinopathy (DR), but the mechanism underlying RPC death is unclear. Although it was postulated in previous studies using bovine RPCs that autoantibodies against RPCs might develop and induce RPC death, it is unknown whether autoantibodies against cell-surface antigens on human RPCs exist in DR patients, whether such autoantibodies contribute to RPC damage/loss, and if they do, through which mechanism. We screened serum samples from DR patients and controls using primary human RPCs and found that that levels of IgGs reactive to RPCs were significantly higher in the DR group than the control group. Serum samples with higher RPC-reactive IgG levels induced more severe complement-mediated RPC damage than those with lower RPC-reactive IgG levels. We also assessed levels of the complement-activation products C3a, C4a and C5a in these serum samples, and found that serum levels of C3a and C5a, but not C4a, were higher in the DR group than control group. These data provide evidence the first time showing that autoantibodies against RPCs can develop in DR patients, and that these autoantibodies could contribute to pericyte damage through complement activation.

Background

In this report, we examine the surgical safety and complications (SC) among 125 liver (L) and 150 kidney (K) HIV+ transplantation (TX) recipients in a prospective nonrandomized U.S. multicenter trial.

Methods

Subjects were required to have CD4+ T-cell counts >200/100 cells/mm3 (K/L) and undetectable plasma HIV-1 RNA (Viral Load [VL]) (K) or expected posttransplantation suppression (L). Impact of SCs (N ≥ 7) was evaluated by use of the proportional hazards models. Baseline morbidity predictors for SCs (N ≥ 7) were assessed in univariate proportional hazards models.

Results

At median 2.7 (interquartile range 1.9-4.1) and 2.3 (1.0-3.7) years after TX, 3-month and 1-year graft survival were [K] 96% (95% CI 91%-98%) and 91% (95% CI 85%-94%) and [L] 91% (95% CI 85%-95%) and 77% (95% CI 69%-84%), respectively. A total of 14 K and 28 L graft losses occurred in the first year; 6 K and 11 L were in the first 3 months. A total of 26 (17%) K and 43 (34%) L experienced 29 and 62 SCs, respectively. In the liver multivariate model, re-exploration was marginally associated (hazard ratio [HR] 2.8; 95% CI 1.0-8.4; P = .06) with increased risk of graft loss, whereas a greater MELD score before transplantation (HR 1.07 per point increase; 95% CI: 1.01-1.14; P = .02), and detectable viral load before TX (HR 3.6; 95% CI 0.9-14.6; P = .07) was associated with an increased risk of wound infections/dehiscence.

Conclusion

The rates and outcomes of surgical complications are similar to what has been observed in the non-HIV setting in carefully selected HIV-infected liver and kidney TX recipients.

Hepatitis C virus (HCV) is a controversial indication for liver transplantation (LT) in human immunodeficiency virus (HIV)-infected patients because of reportedly poor outcomes. This prospective, multicenter US cohort study compared patient and graft survival for 89 HCV/HIV-coinfected patients and 2 control groups: 235 HCV-monoinfected LT controls and all US transplant recipients who were 65 years old or older. The 3-year patient and graft survival rates were 60% [95% confidence interval (CI) = 47%-71%] and 53% (95% CI = 40%-64%) for the HCV/HIV patients and 79% (95% CI = 72%-84%) and 74% (95% CI = 66%-79%) for the HCV-infected recipients (P < 0.001 for both), and HIV infection was the only factor significantly associated with reduced patient and graft survival. Among the HCV/HIV patients, older donor age [hazard ratio (HR) = 1.3 per decade], combined kidney-liver transplantation (HR = 3.8), an anti-HCV-positive donor (HR = 2.5), and a body mass index < 21 kg/m(2) (HR = 3.2) were independent predictors of graft loss. For the patients without the last 3 factors, the patient and graft survival rates were similar to those for US LT recipients. The 3-year incidence of treated acute rejection was 1.6-fold higher for the HCV/HIV patients versus the HCV patients (39% versus 24%, log rank P = 0.02), but the cumulative rates of severe HCV disease at 3 years were not significantly different (29% versus 23%, P = 0.21). In conclusion, patient and graft survival rates are lower for HCV/HIV-coinfected LT patients versus HCV-monoinfected LT patients. Importantly, the rates of treated acute rejection (but not the rates of HCV disease severity) are significantly higher for HCV/HIV-coinfected recipients versus HCV-infected recipients. Our results indicate that HCV per se is not a contraindication to LT in HIV patients, but recipient and donor selection and the management of acute rejection strongly influence outcomes.