The use of gamma-irradiation and ultraviolet-irradiation in the preparation of human melanoma cells for use in autologous whole-cell vaccines.

BACKGROUND: Human cancer vaccines incorporating autologous tumor cells carry a risk of implantation and subsequent metastasis of viable tumor cells into the patient who is being treated. Despite the fact that the melanoma cell preparations used in a recent vaccine trial (Mel37) were gamma-irradiated (200 Gy), approximately 25% of the preparations failed quality control release criteria which required that the irradiated cells incorporate 3H-thymidine at no more than 5% the level seen in the non-irradiated cells. We have, therefore, investigated ultraviolet (UV)-irradiation as a possible adjunct to, or replacement for gamma-irradiation. METHODS: Melanoma cells were gamma- and/or UV-irradiated. 3H-thymidine uptake was used to assess proliferation of the treated and untreated cells. Caspase-3 activity and DNA fragmentation were measured as indicators of apoptosis. Immunohistochemistry and Western blot analysis was used to assess antigen expression. RESULTS: UV-irradiation, either alone or in combination with gamma-irradiation, proved to be extremely effective in controlling the proliferation of melanoma cells. In contrast to gamma-irradiation, UV-irradiation was also capable of inducing significant levels of apoptosis. UV-irradiation, but not gamma-irradiation, was associated with the loss of tyrosinase expression. Neither form of radiation affected the expression of gp100, MART-1/MelanA, or S100. CONCLUSION: These results indicate that UV-irradiation may increase the safety of autologous melanoma vaccines, although it may do so at the expense of altering the antigenic profile of the irradiated tumor cells.

Calciphylaxis and metastatic calcification associated with nephrogenic fibrosing dermopathy.

BACKGROUND: Calciphylaxis and metastatic calcification are known complications of chronic renal failure. Recently, a sclerosing condition of the skin termed nephrogenic fibrosing dermopathy (NFD) has been described in patients with renal disease, many of whom have undergone hemodialysis and/or renal transplantation. To our knowledge, the simultaneous occurrence of both conditions in the same patient, in the same lesion, has not been previously reported. CASE REPORT: We report the clinical, microscopic, and immunohistochemical features of two patients with chronic renal failure whose lesional skin biopsies showed both subcutaneous calcification and NFD. We consider the possible mechanisms that might explain the coexistence of these two disorders. RESULTS: Both patients presented with erythematous, indurated skin over the lower extremities. Purpuric, reticulated patches, necrosis, or ulceration were not observed. Microscopic examination showed the characteristic changes of NFD involving dermis and subcutaneous septa. In addition, biopsies of both individuals showed subcutaneous calcification, one in a diffuse distribution and the other involving the walls of subcutaneous vessels, as seen in calciphylaxis. Calcification was not suspected clinically in either case. CONCLUSIONS: Metastatic calcification or calciphylaxis and NFD can occur simultaneously in patients with chronic renal failure and may be found together in the same lesion. Because subcutaneous calcification may not be suspected clinically in these cases, and in view of the adverse outcomes frequently associated with calciphylaxis, we recommend deep incisional biopsy of patients presenting with the clinical features of NFD. Both the fibrosis and the calcification of chronic renal failure may be related to the activity of transforming growth factor-beta/Smad signaling cascades.