Immunological profiles of HIV-positive recipients of liver transplant

Background: Scarce data are available about immune cell frequencies in HIV-positive recipients of liver transplant. Alterations in immune subsets can lead to persistent immune activation and disease progression or reduced HIV-specific responses. In liver transplantation, impaired immune tolerance can lead to organ rejection.

Methods: HIV-positive subjects with undetectable HIVRNA and CD4 > 100/mm³ were included. Control groups were non-transplanted HIV-positive patients with similar immunovirological parameters and healthy subjects. B cells (memory, transitional, and mature subsets), T cells (effector TH1, nonclassic TH1, TH17, TH1/17; T regulatory naïve and effector subsets and CD8⁺ T regulatory cells), and NK cells (CD56^dim and CD56^bright subsets) were analyzed by flow cytometry.

Results: A total of 56 patients, including 14 HIV-positive transplant recipients (HIV-LT), 14 HIV-positive controls, and 28 healthy controls were included. Median age of HIV-LT patients was 54.9 years with median time from transplant of 7.6 years. Eleven (79%) were HIV/HCV coinfected. Compared to nontransplanted patients, HIV-LT displayed significantly increased frequency of T CD8⁺ cells, lower percentage of T CD4+ cell, and lower number of nonclassic TH1, TH1/17 cells and naïve T CD4⁺ regulatory cells (Tregs). Healthy controls showed increased numbers of B cell subsets and decreased percentage of T effector subpopulations compared to HIV-LT. Compared to HIV-positive patients, healthy controls had higher B cells, NK cells, CD4⁺ T cells, naïve CD4+ Tregs but lower CD8⁺ T cells, effector Tregs, CD8⁺ Tregs, and all T effector cell subsets.

Conclusions: Immune cell subpopulations potentially associated with HIV progression and organ rejection were detected in HIV-positive transplant recipients. We confirmed altered frequencies of B, T, and NK cell populations in HIV-positive liver transplant recipients compared to healthy controls. The imbalance among immune cell subsets deserves further studies to identify markers of transplant outcome and potential therapeutic targets.