Modification of the HCMV-specific IFN-γ release test (QuantiFERON-CMV) and a novel proposal for its application

Human cytomegalovirus (HCMV) is universally distributed among humans without any adverse effects; however, it induces severe diseases in immunocompromised patients such as organ transplant recipients and AIDS patients. To manage these immunocompromised patients, an easy clinical examination for the monitoring of disease risk is required. In this study, we modified the interferon-γ (IFN-γ) release test (QuantiFERON^®-CMV) using HCMV immediate early-1 (IE-1) or pp65 whole proteins, or UV-inactivated HCMV particles as an antigen. The response of heparinized peripheral blood from healthy volunteers to the pp65 protein showed an obvious dose-dependent sigmoid curve, although no correlation was observed between results of this assay and an ELISPOT assay. The addition of pp65 to the blood samples at a final concentration of 1×10³ to 1×10⁵ pg/ml was found to be optimum. Using this assay, we observed a significant enhancement in cellular immunity in volunteers after the daily ingestion of yogurt for 8 weeks, which suggested a novel application of the assay in addition to monitoring HCMV infection risk. IFN-γ secretion from peripheral blood cells on HCMV-antigen stimulation differed significantly between individuals; therefore, the assay could not be normalized. Nevertheless, it was found to be particularly useful for observing fluctuations in cellular immune activity on an individual level.

Cytomegalic inclusion disease in the adult

The distribution of infected cells in 13 necropsies on adults with cytomegalovirus disease is reported and discussed in relation to the local damage caused by the infection and predisposing factors. The distribution, with lung as the most common site, but other organs such as thyroid, liver, and colon not infrequently involved, agrees fairly well with other series. No heavy infection confined to one organ was found, and it is concluded that a truly localized infection in the adult probably does not occur. Evidence of destructive inflammatory changes attributable to the virus was scanty; a lymphocyte and plasma cell infiltrate was sometimes found, and microglial nodules were found in a case with inclusions in the brain. In one case heavy cytomegalovirus infection in the colon was associated with, and probably caused, marked colonic ulceration which led to the death of the patient. THE MAJOR PREDISPOSING FACTOR TO INFECTION IN THIS SERIES WAS CORTICOSTEROID THERAPY: eight of the 13 patients had been treated with steroids and one had Cushing's syndrome associated with a bronchial carcinoma. Three of the other four patients had a very few inclusions only. Adrenal involvement was not found in any of the steroid-treated patients but was present in two of the four patients not treated with steroids where adrenal sections were available. It is concluded that most adult patients with cytomegalovirus infection have impaired immune mechanisms, and that heavy infection may rarely lead to a clinically serious disease.