[Clinical characteristics of tuberculosis in the aged]

We prospectively studied the clinical characteristics of tuberculosis in the aged from July 1988 to March 1989. Twenty-five of 101 tubercle-bacilli positive patients were 70 years old or more. In these aged patients, decrease of body weight and of serum albumin was predominant. These findings suggest that undernutrition is remarkable in aged patients with tuberculosis, and it may influence their cellular immunity. In fact, the tuberculin reaction was significantly attenuated in the aged patients compared with patients less than 70 years old. Twelve percent of the aged patients showed a negative tuberculin reaction. In clinical diagnosis, it should be kept in mind that tuberculin reaction is sometimes negative in active tuberculosis patients particularly in the aged. The time required for negative conversion of tubercle bacilli was not retarded in the aged patients due to the use of potent chemotherapy regimens containing isoniazid and rifampicin.