A comparison of delayed hyper-sensitivity (DHT) in adult Cystic Fibrosis with sarcoidosis and HIV infected patients

As more Cystic Fibrosis patients are surviving into adulthood, aspects of this disease remain unknown to us including the immune status of the cystic fibrosis patient. This is particularly relevant to a patient group vulnerable to infection and where treatment may include lung transplantation. The aim of this study was to assess the immune status of an adult cystic fibrosis group (n=7) by studying delayed hypersensitivity (DHT) and to compare the DHT response in this group with that of control volunteers (n=10), sarcoidosis (n=10) and HIV infected patients (n=7). DHT was assessed by recording the skin test (Merieux Multitest) response to diphtheria, tetanus, streptococcus, candida, tuberculin, tricophytan and proteus miribalis antigens, and by in-vitro lymphoblastogenesis to tuberculin antigen. It was hypothesised that the DHT profile of the adult cystic fibrosis group might be unique to this condition and that further information about this might help in the assessment and treatment of infections like invasive pulmonary aspergillosis and pulmonary aspergillomas, especially in those who undergo lung transplantation. In this study, the degree of reactivity to skin testing to all the antigens and the lymphoblastogenesis response to tuberculin antigen was found to be significantly greater in the cystic fibrosis group (p<0.05) compared to controls, sarcoidosis and HIV infected patients. No significant relationship however was found between positive reactors to tuberculin skin testing and the size of the lymphoblastogenesis response. Finally, in keeping with current concepts, sarcoidosis and all HIV infected patients with CD4 count < 400 were found to be anergic to tuberculin on skin testing. These results suggest that DHT in the adult cystic fibrosis patient is unique and predominantly intact, a factor which may prove relevant, in the future, in the assessment and treatment of infections in cystic fibrosis particularly in those undergoing lung transplantation.