Immunological profiles in patients with acute retinal necrosis

Acute retinal necrosis (ARN) is a newly recognized disease caused by human commensal viruses of the herpes family (herpes simplex virus, varicella-zoster virus and cytomegalovirus) occurring in apparently immunocompetent patients. As at least three viruses can cause ARN, the modification in the host-virus interaction at the origin of the disease most probably comes from the host. A review of 216 reported cases of ARN showed that there were signs of impaired cellular immunity in 16% of these cases. The purpose of this study was to investigate immune parameters in ARN.

In nine HIV-negative ARN patients who were not under steroid or immunosuppressive therapy, the following prospective immunological investigations were performed: (1) skin testing for delayed-type hypersensitivity to seven common antigens (Candida, diphtheria, purified protein derivative tuberculin Proteus, Streptococcus, tetanus, Trichophyton); (2) lymphocytic proliferative responses in vitro to these antigens and to three mitogens; (3) determination of blood lymphocyte sub-populations by flow cytometry.

Cutaneous anergy was found in five of seven tested cases. The lymphocyte proliferative index was less than 20% of the index of a control group for all antigens in three of nine cases, and for three or more antigens in eight of nine cases. In eight of nine cases there was a relative increase of B-lymphocytes, and in seven of nine cases B-lymphocytes were also increased in absolute numbers. In all nine cases one or more of these parameters were abnormal.

Our findings suggest that ARN may develop in association with an imbalance of the immune system characterized by an impaired cellular response and/or a maintained or increased humoral response.