The relationship between natural killer cell activity and delayed-type hypersensitivity reaction to 2,4-dinitrochlorbenzene in the spectrum of chronic, intractable pulmonary tuberculosis.

We examined natural killer (NK) cell activity and delayed-type hypersensitivity reaction to 2,4-dinitrochlorbenzene (DNCB) in the spectrum of chronic, intractable pulmonary tuberculosis. A high reactive group as defined by high NK cell activity and positive reaction to DNCB were characterised by stable clinical courses assessed by radiographical and clinical changes. A low reactive group defined by non-augmented NK cell activity and negative reaction to DNCB were characterised by progressive clinical courses. Although far advanced radiographic lesions were observed more frequently in the low reactive group and moderately advanced lesions more frequently in the high reactive group, there was not a significant statistical trend.