Kefei Kang

Thymopoietin pentapeptide (TP-5) improves clinical parameters and lymphocyte subpopulations in atopic dermatitis.

In a double-blind prospective study, eighteen patients with atopic dermatitis (AD) were treated with thrice-weekly injections of 50 mg thymopoietin pentapeptide (TP-5) or placebo for 6 weeks. Clinical parameters, lymphocyte subsets defined by monoclonal antibodies, and serum IgE were modified. Younger patients (age less than 34) responded to TP-5 with much greater improvement in severity scores than TP-5-treated patients of age greater than 34 or than placebo-treated patients of either age group (p less than 0.05). Both absolute lymphocytes and OKT8+ cytotoxic/suppressor cells were significantly increased (p less than 0.05) in the TP-5 group, whereas they were not significantly increased in the placebo group (p greater than 0.05). Conversely, Ia+ cells were significantly increased in the placebo group (p less than 0.05), but remained the same in the TP-5 group (p greater than 0.05). Serum IgE levels were not significantly altered in either group. Thus, TP-5 had a beneficial clinical effect in AD, especially in younger patients, and increased the reduced OKT8+ cytotoxic/suppressor T cells and prevented an increase of Ia+ cells during pollen season.

FcIgG Receptor-Bearing Lymphocytes and Monoclonal Antibody-Defined T Cell Subsets in Atopic Dermatitis: Effect of Treatment with Thymopoietin Pentapeptide (TP-5)

Lymphocyte subpopulations were determined in the blood of patients with atopic dermatitis (AD) before and after treatment with the thymopoietin pentapeptide TP-5. The relative and absolute numbers of lymphocytes bearing suppressor/cytotoxic cell markers (FcIgG+E+ and T8+ cells) were significantly decreased in the untreated patients and the T4+/T8+ cell ratio was increased, indicating an imbalance between lymphocyte subpopulations in AD. Patients who had been treated for 6 weeks with TP-5 displayed no significant abnormality of any of the lymphocyte subsets studied and comparison of pre- and posttreatment values revealed that there was a statistically significant increase in T8+ cell numbers, that by contrast did not take place in placebo-treated AD patients. The treatment had no demonstrable effect on IgE serum levels or on the spontaneous in vitro production of IgE by cultured lymphocytes from the patients.

Immunosuppression in a homosexual man with Kaposi's sarcoma

The occurrence of Kaposis sarcoma in young homosexual men is a recently reported condition. The same individuals are at risk for the development of Pneumocystis carinii pneumonia and other unusual infections. These associations suggest these persons are somehow immunocompromised. Evidence of current or prior cytomegalovirus (CMV) infection is seen in a high percentage of these and other homosexual men. CMV infections are known to induce alterations in the immunoregulatory suppressor and helper T lymphocyte populations. The CMV infection is suspect as the cause of immunosuppression in these individuals. We present a case of Kaposis sarcoma in a homosexual men with CMV cultured from his urine and semen. He showed a marked increase in his suppressor/cytotoxic cell (OKT8-positive) population, as well as a marked decrease in his helper cell (OKT4-positive) population. Mitogen and antigen studies demonstrated absent or markedly diminished response both in vitro and in vivo. Pokeweed mitogen (PWM)-induced IgG synthesis appeared normal. This patient, as well as the majority of other reported patients with this disease, manifested the HLA-Dr5 phenotype. The immunosuppression in this patient and possibly other similar men appears to be mediated by abnormalities in the immunoregulatory T lymphocytes.