An open clinical trial of
thymopentin was conducted on 16 children with severe
atopic dermatitis. The patients were treated with
injections three times a week of 50 mg
thymopentin for six weeks. They were then divided randomly into two groups: group A continued
thymopentin for an additional six weeks, and group B were treated with
normal saline. Clinical parameters and immunological function were evaluated serially. The total severity score started to decline from baseline significantly three weeks
after treatment, and continued throughout the study period in group A but began to flare up in group B two weeks after stopping
thymopentin. All the eight patients in group A completed the trial but three out of eight in group B dropped out because of flaring up of skin lesion. In vitro production of
interleukin-4 tended to decrease and that of
interferon gamma tended to increase, but total serum
IgE, in vitro
IgE synthesis, and abnormally low CD8+ CD11b+ suppressor T cells remained unchanged.
Histamine releasing factor (HRF), plasma
histamine, and respiratory burst activities of polymorphonuclear leucocytes were appreciably decreased after
thymopentin treatment. It is concluded that the clinical efficacy of short term
thymopentin treatment very possibly results from the decreased production of HRF and decreased release of polymorphonuclear leucocyte derived inflammatory mediators and may have no relation with
antigen-
IgE immune reaction.