Abstract
SUMMARY Present immunological methods do not regularly detect abnormalities in patients with chronic bronchitis, and no single parameter appears to be closely associated with the clinical findings. Of the many tests performed in the cited studies, the Merieux multitest procedure seems to offer the best findings in further studies, followed by determination of the OKT4/OKT8 ratio.The theoretical background for the use of an immunologic approach to prevent frequent recurrences of infections is discussed in depth, with particular emphasis on the pharmacologic efficacy profile of thymopentin. The safety of this drug is remarkably unproblematic.The present survey of 11 clinical studies shows that thymopentin treatment reduces the incidence of recurrent respiratory tract infections. The most frequently used dosing regimen is 50 mg SC three times a week for 6 weeks, which may be repeated after 3–6 months. The clinical effect appears long‐lasting, ie, 3–4 months after discontinuation of treatment.