Spontaneous regression of human melanoma/nonmelanoma skin cancer: association with infiltrating CD4+ T cells.

Spontaneous regression occurs in some human malignant melanomas and basal cell carcinomas (BCCs). We have compared the cellular infiltrate in regressing and nonregressing tumors in order to analyze the mechanism by which regression occurs. Regressing primary melanomas and BCCs were infiltrated with a larger number of CD4+, but not CD8+, T lymphocytes than were seen in nonregressing tumors. The number of interleukin 2 receptor-positive (early activation marker) but not transferrin receptor-positive (intermediate activation marker) T cells was increased, indicating that the infiltrating T cells were activated. Large numbers of Langerhans cells, macrophages, and other class II major histocompatibility complex (MHC)-expressing cells were present but were not increased in the regressing tumors. There were no detectable B lymphocytes, and the regressing tumor cells displayed levels of HLA-DR expression similar to those of the nonregressing tumors. Comparison of squamous cell carcinoma (SCCs) with keratoacanthomas (KAs), which are likely to be a spontaneously regressing form of SCC, also showed increased infiltration of activated CD4+, but not CD8+, T cells within the KA. A murine ultraviolet (UV)-induced squamous tumor that spontaneously regresses when transplanted into immunocompetent syngeneic mice was also infiltrated with increased numbers of activated CD4+, but not CD8+, T cells prior to and during rejection. These results indicate that spontaneous regression of human skin tumors is likely to be immunologically mediated, and that CD4+ T lymphocytes seem to mediate this regression.

Immunocytochemical analysis of the cellular infiltrate in primary regressing and non-regressing malignant melanoma.

Spontaneous regression occurs in a small proportion of malignant melanomas, and it is important to understand the processes involved in its induction as this may give a guide to future therapies for this disease. We have examined 36 primary malignant melanomas (19 regressing, 17 non-regressing) and identified the cellular phenotypes and activation states of the cells infiltrating regressing and non-regressing primary melanomas by immunochemistry. We have found a significantly increased number of CD3-positive cells and an increased ratio of CD4/CD8-positive cells infiltrating regressing compared to non-regressing tumors. In addition, the expression of the interleukin 2 receptor, an activation marker for T cells, was increased. However, there were no significant differences in class II MHC, CD1, intercellular adhesion molecule 1 (ICAM1), or melanoma-associated differentiation-antigen expression in these tumors. These data are consistent with melanoma regression being induced by activated CD4 T cells and do not seem to be related to the differentiation markers we have examined on these tumors.

A neutrophilic reaction of Sweet's syndrome type associated with the oral contraceptive.

A case is presented of a Sweet's syndrome-like eruption in association with the oral contraceptive. A 46 year old caucasian woman developed recurrent episodes of erythematous tender plaques on her trunk six weeks after commencement of the oral contraceptive (OC). Her condition clinically and histologically resembled Sweet's dermatosis. On cessation of the OC there was complete resolution of her lesions and she remains well 12 months later. This is the first report, to our knowledge, of a neutrophilic reaction to the oral contraceptive, and we believe that drugs may be implicated in the aetiology of atypical neutrophilic reactions simulating Sweet's syndrome in patients who are otherwise well.

PIP: Physicians examined a 46 year old woman who came to Lidcombe Hospital in Lidcombe, New South Wales in Australia experiencing recurrent painful eruptions on the skin of her back, chest, and shoulders. General malaise and fever accompanied these eruptions of 2-3 week duration. Due to menstrual irregularities, she began taking the phasic oral contraceptive (OC). Triphasil 6 weeks before the 1st eruption occurred. The findings of laboratory investigations suggested Sweet's syndrome. She then took oral prednisone for 6 months and the lesions disappeared. Upon completion of prednisone, she again suffered from recurrent episodes. This time she did not have a fever. Her ESR levels had fallen from 40-17 mm between initial examination and examination after prednisone use. Neutrophilia was 76% . The physicians then made a diagnosis of Sweet's like dermatosis or drug eruption secondary to the OC. They suggested to the women to cease taking the OC. She then experienced no more lesions. 12 months later her blood count was normal and no more painful episodes occurred. The physicians suggested that the woman had a hypersensitive reaction to the OC. 2 other drugs have also been implicated to cause Sweet's syndrome--hydralazine and trimethoprim-sulphamethoxazole.

Oysters, iron overload and Vibrio vulnificus septicaemia.

A case of Vibrio vulnificus septicaemia complicated by cutaneous leg ulceration is described. A 74 year old man with haemochromatosis and sideroblastic anaemia developed an acute febrile illness with cutaneous manifestations 24 hours after ingesting raw oysters. The presence of blistering should be considered an important clue to the diagnosis of Vibrio vulnificus septicaemia, and this can facilitate prompt effective antimicrobial therapy. Clinicians should be aware of this infection because of its high case fatality rate, especially in patients with iron overload states.