Retinal microvasculopathy in human immunodeficiency type 1 (HIV)-infected children

Ophthalmic manifestations of perinatally acquired HIV in a US cohort of long-term survivors

BACKGROUND/AIMS

To determine the ophthalmic manifestations of HIV in a cohort of long-term survivors of perinatally acquired HIV.

METHODS

Twenty-two patients with perinatally acquired HIV who were aged ≥12 years were prospectively studied at a university clinic. They underwent complete ophthalmic examinations and fundus photography. Their medical histories, medications and CD4 counts were abstracted from the medical records. To evaluate for keratoconjunctivitis sicca, both HIV patients and 44 healthy controls (matched by age, gender and contact lens wear) underwent Schirmer testing and ocular surface staining.

RESULTS

Nine male and 13 female HIV patients with mean age of 16.6 years (SD, 3.4) were examined. Of the 22 HIV patients, 21 had been treated with highly active antiretroviral therapy (HAART). Only one patient had a CD4 count nadir of <200 cells/µL. The mean visual acuity of the eyes of the HIV subjects was 20/22 (SD, 1.6 lines). No patient had cytomegalovirus retinitis. Four of the 22 (18%) HIV patients had strabismus. HIV subjects and controls had similar rates of abnormal Schirmer (9% and 14%, p=0.62) and ocular staining scores (p=0.29).

CONCLUSIONS

In the post-HAART era, long-term survivors of perinatally acquired HIV exhibited little vision-threatening disease, but had a high prevalence of strabismus.

HIV-1 Tat-mediated apoptosis in human blood-retinal barrier-associated cells

HIV-1-associated ocular complications, such as microvasculopathies, can lead to the loss of vision in HIV-1-infected patients. Even in patients under highly active antiretroviral therapy, ocular lesions are unavoidable. Ocular complications have been demonstrated to be closely related to the breakdown of the blood-retinal-barrier (BRB); however, the underlying mechanism is not clear. The data from this study indicated that the HIV-1 Tat protein induced the apoptosis of human retinal microvascular endothelial cells (HRMECs) and retinal pigmen epithelium (RPE) cells, which compose the inner BRB and the outer BRB, respectively. In addition, this study found that the activation of N-methyl-D-aspartate receptors (NMDARs) was involved in the apoptosis of RPE cells, but it caused no changes in HRMECs. Furthermore, both cell types exhibited enhanced expression of Bak, Bax and Cytochrome c. The inhibition of Tat activity protected against the apoptosis induced by NMDAR activation and prevented the dysregulation of Bak, Bax and Cytochrome c, revealing an important role for the mitochondrial pathway in HIV-1 Tat-induced apoptosis. Together, these findings suggest a possible mechanism and may identify a potential therapeutic strategy for HIV-1-associated ocular complications.