Validation of the East London Retinopathy of Prematurity algorithm to detect treatment-warranted retinopathy of prematurity: a cohort study.

AIM: To validate the East London Retinopathy of Prematurity algorithm (EL-ROP) in a cohort of infants at risk of developing retinopathy of prematurity (ROP). METHODS: The EL-ROP algorithm was applied retrospectively to routinely collected data from two tertiary neonatal units in England on infants eligible for ROP screening. The EL-ROP recommendation, to screen or not, was compared with the development of treatment-warranted ROP (TW-ROP) for each infant. The main outcome measures were (1) EL-ROP's sensitivity for predicting the future development of TW-ROP and (2) potential to reduce ROP screening examinations. RESULTS: Data from 568 infants were included in the trial. The median (IQR) birth weight (g) was 875 (704 - 1103) and gestational age (weeks) was 27.0 (25.4 - 29.0). Maternal ethnicity was black (33%) and non-black (67%). 58(10%) developed TW-ROP and in every case this was predicted by the EL-ROP algorithm. It's sensitivity was 100% (95% CI 94-100%) specificity: 44% (95% CI 39-48%) positive predictive value: 17% (95%CI 16-18%), negative predictive value: 100%. CONCLUSIONS: EL-ROP has been validated in a cohort of infants from two tertiary neonatal units in England. Further validation is required before its clinical usefulness can be assessed.

Pharmacologic HIV-1 Nef blockade promotes CD8 T cell-mediated elimination of latently HIV-1-infected cells in vitro.

Eradication of the HIV-1 latent reservoir represents the current paradigm to developing a cure for AIDS. HIV-1 has evolved multiple mechanisms to evade CD8 T cell responses, including HIV-1 Nef-mediated downregulation of MHC-I from the surface of infected cells. Nef transcripts and protein are detectable in samples from aviremic donors, suggesting that Nef expression in latently HIV-1-infected CD4 T cells protects them from immune-mediated clearance. Here, we tested 4 small molecule inhibitors of HIV-1 Nef in an in vitro primary CD4 T cell latency model and measured the ability of autologous ex vivo or HIV-1 peptide-expanded CD8 T cells to recognize and kill latently infected cells as a function of inhibitor treatment. Nef inhibition enhanced cytokine secretion by autologous CD8 T cells against latently HIV-1-infected targets in an IFN-γ release assay. Additionally, CD8 T cell-mediated elimination of latently HIV-1-infected cells was significantly enhanced following Nef blockade, measured as a reduction in the frequency of infected cells and Gag protein in cultures following viral outgrowth assays. We demonstrate for the first time to our knowledge that Nef blockade, in combination with HIV-specific CD8 T cell expansion, might be a feasible strategy to target the HIV-1 latent reservoir that should be tested further in vivo.

HIV-Specific Granzyme B-Secreting but Not Gamma Interferon-Secreting T Cells Are Associated with Reduced Viral Reservoirs in Early HIV Infection.

A major barrier to a human immunodeficiency virus type 1 (HIV-1) infection cure is the establishment of a viral reservoir in spite of combined antiretroviral therapy (cART). It is unclear how HIV-specific cytotoxic T lymphocytes (CTLs) influence the size of the reservoir in early HIV infection. Twenty-eight subjects with early HIV infection were recruited to receive cART and followed for 48 weeks. HIV reservoirs in peripheral CD4+ T cells measured by cell-associated proviral DNA and viral outgrowth cultures were determined at baseline and after 48 weeks of cART. At baseline, granzyme B and gamma interferon (IFN-γ) enzyme-linked immunosorbent spot (ELISpot) assays were performed with peptides spanning the HIV proteome. All subjects had detectable HIV-specific granzyme B and IFN-γ responses at baseline. The quantity and specificity of granzyme B responses did not correlate with IFN-γ responses. For granzyme B, Tat/Rev was the most dominant whereas for IFN-γ, Gag predominated. HIV-specific granzyme B T cell responses negatively correlated with HIV proviral loads at baseline and at 48 weeks and with replication-competent viral infectious units per million (IUPM) CD4+ T cells at baseline but not significantly at 48 weeks. Tat/Rev-, Env-, Gag-, and Vif-specific granzyme B responses correlated most strongly with reservoir control. There was no correlation of HIV-specific IFN-γ responses with reservoir size at baseline or at 48 weeks. The majority of granzyme B responses were contributed by CD8+ T cells. Thus, our findings suggest that the induction of potent granzyme B-producing CTLs to Tat, Rev, Env, Gag, and Vif during early infection may be able to prevent the establishment of a large viral reservoir, thereby facilitating a reduced HIV burden.IMPORTANCE A major barrier to the cure of human immunodeficiency virus type 1 (HIV-1) infection is the establishment of a viral reservoir that must be significantly reduced or eradicated entirely to enable a cure. Combined antiretroviral therapy (cART) alone is unable to clear this viral reservoir. It has been shown that CD8+ cytotoxic T lymphocytes (CTLs) are important in controlling early HIV infection by reducing plasma viremia. However, it is not known if these HIV-specific CTLs influence the establishment of the viral reservoir in early HIV infection. We show that HIV-specific granzyme B responses targeting HIV Tat/Rev, Env, Gag, and Vif, but not IFN-γ responses, are associated with reduced virus reservoirs at baseline and at 48 weeks of cART. These findings shed light on the nature of the effector CTL response that might limit reservoir size with implications for cure research and HIV vaccines.