In vitro lymphoblastoid transformation in the presence of tuberculin as a diagnostic aid in tuberculous meningoencephalitis.

Abstract

Precise diagnosis of tuberculous meningoencephalitis is often not possible because of the poor rate of isolation of acid-fast bacilli from cerebrospinal fluid and the negative response to intradermal tuberculin in a large number of patients. A tissue culture test measuring blastoid transformation of peripheral blood lymphocytes in the presence of tuberculin purified protein derivative was eval­ uated as a diagnostic approach in 24 patients with meningoencephalitis. An in vitro response to purified protein derivative was obtained in 20. Demonstration of tuberculin sensitivity in these patients provided confirmatory evidence of infection with Mycobacterium tuberculosis. Only in 6 of these 20 patients could the diagnosis be made confidently from other data. It was concluded that the in vitT,) lymphoblastoid transformation in the presence of purified protein derivative may be a useful diagnostic aid in patients suspected of having tuberculous meningoencephalitis.