A study of costimulatory factors in tonsils of pustulosis palmaris et plantaris

Abstract

Pustulosis palmaris et plantaris (PPP) is known to be closely related to tonsillar focal infections and tonsillectomy is quite effective. Hyper-immune response to alpha streptococci in patients with PPP was reported. On the other hand, costimulatory factors were studied on autoimmune disease. CD28 and cytotoxic T lymphocyte-associated 4 (CTLA4) participate in these factors. CD28 take part in T-cell activation, while CTLA4 take part in T-cell suppression. Therefore, we investigated CD28 and CTLA4 mRNA levels by reverse transcription-polymerase chain reaction (RT-PCR) in tonsillar tissues and CD3 positive lymphocytes from patients with PPP, recurrent tonsillitis (RT), and obstructive sleep apnea syndrome (OSAS). We also investigated the expression levels of CD28 and CTLA4 by flow cytometry analysis in tonsillar mononuclear cells stimulated with alpha streptococci in these patients. It was revealed that the CTLA4 mRNA in tonsillar CD3 positive lymphocytes from PPP patients was expressed at lower level than non-PPP patients. Then, the expression levels of CTLA4, comparison before and after stimulation, were lower level in PPP patients than non-PPP patients. These results suggest that the lower expression level of CTLA4 in PPP may cause hyper-immune response to alpha streptococci and abnormal regulation of T-cell activation.