Siba G. Chakrabarti

Aberrations in T lymphocytes and natural killer cells in vitiligo: A flow cytometric study

Twenty-five patients with vitiligo and twenty-five healthy control subjects were evaluated with the use of flow cytometry to compare percentages of peripheral T lymphocytes and natural killer cells. The percentages of total T lymphocytes, helper T cells, suppressor T cells, and natural killer cells were evaluated with the use of OKT3, OKT4, OKT8, and Leu-7 monoclonal antibodies, respectively. Mean total T lymphocytes and helper T cells were markedly depressed; mean natural killer cells were markedly elevated and mean suppressor T cells were moderately elevated in patients with vitiligo in comparison with control subjects. These results indicate that cell-mediated immunity is subject to some defect in regulation in patients with vitiligo. It remains to be determined whether these abnormalities are a direct cause or a result of vitiligo. Antibody-dependent cytotoxicity, utilizing killer cells with recently reported antimelanocyte antibodies found in patients, may be responsible for pigment cell destruction in vitiligo. Helper T cells may be reduced because of low levels or faulty production of T lymphocyte-stimulating factors in patients or because of a serum factor in patients that is toxic to helper T cells. The presence or absence of autoimmune and/or endocrine disease in patients with vitiligo had no effect on lymphocyte populations. There seemed to be a trend toward lower levels of helper T cells in patients having vitiligo for the shortest amount of time. In summary, the data indicate immunologic abnormalities in patients with vitiligo.

Ocular disturbances in vitiligo

One hundred fifty-six patients with vitiligo were examined for ocular abnormalities. A 2:3 ratio of white to black patients allowed us to evaluate the role of race in the occurrence of ocular disturbances. A large percentage (40%) of all patients showed some degree of fundal pigment disturbance including pigment clumps, focal hypopigmented spots, and choroidal nevi. Although racial variations were found in the incidence of choroidal nevi (p = 0.001) and iris transillumination (p = 0.0012), these variations were believed to reflect normal differences found in patients without vitiligo.

Determination of optimal topical photochemotherapy for vitiligo

The efficacy of topical 8-methoxypsoralen (8-MOP) in varying concentrations and vehicles was assessed in 73 vitiligo patients. The response rates in different anatomic sites were also assessed. Seven patients (9%) had 100% repigmentation; 26 (36%) had 50% or greater repigmentation, 29 (40%) had some degree of pigment return, but less than 50%; 11 (15%) had no repigmentation. Results suggest that neither concentration of drug nor vehicle is a crucial factor for inducing repigmentation of vitiliginous patches on the face, trunk, and extremities. Low-dose 8-MOP (0.1%) was as effective as high dose 8-MOP (0.5%, 1%), while causing fewer side effects. However, when treating recalcitrant areas (distal extremities), 1% 8-MOP may be the most efficacious preparation for topical photochemotherapy. A phototoxic response preceded repigmentation in all cases. The following responses were obtained for the various anatomic sites treated: 56% of facial lesions; 35% of trunk areas; 36% of the extremities, and 13% of the recalcitrant areas had greater than 50% repigmentation.

RETINITIS PIGMENTOSA ASSOCIATED WITH HEARING LOSS, THYROID DISEASE, VITILIGO, AND ALOPECIA AREATA: Retinitis Pigmentosa and Vitiligo

A 54-year-old woman with retinitis pigmentosa and hearing loss developed white skin patches that were subsequently diagnosed as vitiligo. A review of the literature reveals that, although the association of vitiligo with various tapedoretinal degenerations has been reported on several occasions, the association with typical retinitis pigmentosa is quite rare. This combination of disorders associated with pigment loss is of interest as immunologic disturbances have been implicated on both.