Human mucosal-associated invariant T (MAIT) cells express the semi-invariant T cell receptor Vα7.2 and are restricted by the MHC-Ib molecule MR1. While MAIT cells share similarities with other innate T cells the extent to which MAIT cells are innate and their capacity to adapt is unknown. We evaluated the function of Vα7.2 + T cells from the thymus, cord blood, and peripheral blood. While antigen-inexperienced MAIT cells displayed a naive phenotype these had intrinsic effector capacity in response to Mycobacterium tuberculosis infected cells. Vα7.2 + effector thymocytes contained sjTREC suggesting limited replication and thymic origin. In evaluating the capacity of Mtb-reactive MAIT cells to adapt, we found that those from peripheral blood demonstrated a memory phenotype and had undergone substantial expansion suggesting they responded to antigenic stimulation. MAIT cells, an evolutionarily conserved T cell subset that detects a variety of intracellular infections, share features of innate and adaptive immunity.

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To determine prevalence of glaucoma subtypes and legal blindness in patients on their first visit to an ophthalmic center in the western region of Saudi Arabia a chart review analysis was carried out of new patients in 2006 with glaucoma diagnosis in our Glaucoma Unit. Diagnosis was confirmed clinically and by glaucoma workup. The main outcome was prevalence of glaucoma types and legal blindness from glaucoma. Of 2,354 new patients in 2006, 417 were glaucomatous. Mean age was 56.4 years and mean intraocular pressure (IOP) was 26.5 mmHg; 54.4% had prior glaucoma diagnosis. Prevalence of primary open-angle glaucoma was 30.5%, primary angle-closure 24.7%, neovascular 7.6%, surgically induced 6.5%, and exfoliative 5.2%. One-third of patients were unilaterally legally blind, whereas 11.3% were bilateral. Primary glaucoma represents two-thirds of glaucoma cases in Saudi Arabia. Approximately one-half of patients were legally blind in at least one eye at time of presentation.

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