EFFECTIVENESS OF THYMOSTIMULIN AND STUDY OF LYMPHOCYTE-DEPENDENT ANTIBACTERIAL ACTIVITY IN CHILDREN WITH RECURRENT RESPIRATORY-INFECTIONS

Recurrent respiratory infections (RRI) consist of more relapsing acute respiratory infections than the ones expected for the age [> 6 acute respiratory tract infections (RTI) per year if age is > 3 years, and > 8 acute RTI per year if age is < 3 years]. Concerning the pathogenesi s of RRI, several investigations report the important role of environm ental factors, early socialization and immunological dysfunctions, suc h as lymphocyte subpopulations alterations, IgG subclass deficiency an d phagocytosis and/or opsonization deficit during acute infections. In this framework, we have studied the lymphocyte-dependent antibacteria l activity (ABA) among 121 children affected by RRI. Results show a st atistically significant alteration of this function in 38 children (31 .4%): 19 of them exhibited an absent ABA (group 1), while in the other s same function was reduced (group 2). A bovine thymic extract, thymos timulin, was administered to both groups by intramuscular injections ( 1mg/kg) for a 3 month cycle. At the end of therapy we observed a stati stical significant rise of ABA only in group 1 and among children aged > 3 years. Among the same patients, 33 children (86.8%) improved in t erms of reduction of clinical score and better results were seen among children aged > 3 years. These data emphasize the beneficial role of thymostimulin in RRI-affected children, suggesting a transient immatur ity of the immune system as one of the possible pathogenetic factor.