[Usefulness of MT-2 assay to decide when to start anti-HIV therapy]

It is well known that the emergence of syncytium inducing (SI) variant correlates accelerated CD4 decline and disease progression during the course of HIV infection. We have conducted a clinical study to investigate whether or not detection of SI by MT-2 cells (MT-2 assay) can be a clinical marker to decide when to start anti-HIV therapy since 1995. We examined 483 blood samples obtained from 172 HIV-infected patients by the MT-2 assay. SI was detected from 20 patients. There were five untreated patients whose CD4 counts were 300/microliter or more. Anti-HIV combination therapies were started soon after detection of SI in all of them. We have followed their clinical courses for more than 4 years, so far, in three of them. Their CD4 counts and clinical courses were both stable. In contrast, in another patient who could not receive any anti-HIV therapy even though SI positive, decline of CD4 was very rapid (200/microliter/year) and the disease progressed to AIDS within one year as like other SI positive cases before the era of several approved anti-HIV drugs. According to these distinct prognosis, the MT-2 assay might be a useful clinical marker for deciding anti-HIV therapy at least in our limited cases.