PUVA-induced pityriasis lichenoides chronica-like papular lesions in patients with mycosis fungoides: a clinical, histopathological and immunohistochemical study.

Mycosis fungoides (MF) is the most common form of cutaneous T cell lymphoma (CTCL) with many clinical variants including papular and pityriasis lichenoides chronica (PLC)-like variants. During psoralen and ultraviolet A (PUVA) treatment of MF, PLC-like papular lesions were observed to appear. The exact nature of these lesions is not fully understood. This work aimed to study PLC-like papular lesions arising in MF patients receiving PUVA therapy clinically, histopathologically and immunohistochemically (using monoclonal antibodies against CD4 and CD8) and to compare them with lesions in classic PLC patients. Fifteen MF patients with PLC-like papular lesions arising during PUVA treatment were included and 15 patients with classic PLC served as controls. While the extent of these lesions significantly correlated with their duration (p < 0.05), it showed no significant correlation with the TNMB stage of MF, number of phototherapy sessions or cumulative UVA dose at which they started to appear. The response status of MF to PUVA did not affect their development. Compared to classic PLC, these lesions showed significantly more acute onset (p = 0.003). None of these lesions showed histopathological features essential to diagnose papular/PLC-like MF and no significant difference existed with regard to their histopathological and CD4/CD8 phenotypic features compared to classic PLC. Papular lesions mimicking PLC in MF patients receiving PUVA mostly represent an upgrading reaction with possible good prognostic implication.

Hypopigmented Interface T-Cell Dyscrasia and Hypopigmented Mycosis Fungoides: A Comparative Study.

Hypopigmented interface T-cell dyscrasia (HITCD) is a distinct form of lymphoid dyscrasia that may progress to hypopigmented mycosis fungoides (HMF). We compared both diseases as regards their CD4/CD8 phenotype and expression of granzyme B and tumor necrosis factor-alpha (TNF-α) and how these are affected by narrow-band UVB (nb-UVB). The study included 11 patients with HITCD and 9 patients with HMF. They received nb-UVB thrice weekly until complete repigmentation or a maximum of 48 sessions. Pretreatment and posttreatment biopsies were stained using anti CD4, CD8, TNF-α, and granzyme B monoclonal antibodies. Epidermal lymphocytes were CD8 predominant in 54.5% and 66.7% of HITCD and HMF cases, respectively, whereas dermal lymphocytes were CD4 predominant in 63.6% and 66.7%, respectively. Significantly, more dermal infiltrate was encountered in HMF (P = 0.041). In both diseases, granzyme B was only expressed in the dermis, whereas TNF-α was expressed both in the epidermis and dermis. No difference existed as regards the number of sessions needed to achieve repigmentation or cumulative nb-UVB dose reached at end of study. (P > 0.05). Narrow-band UVB significantly reduced only the epidermal lymphocytes in both diseases (P ≤ 0.05) with their complete disappearance in 8 (72.7%) HITCD and 6 (66.7%) HMF cases. In both diseases, nb-UVB did not affect granzyme B or TNF-α expression (P > 0.05). In conclusion, both diseases share the same phenotype, with HITCD being a milder form of T-cell dysfunction. In both diseases, epidermal lymphocytes are mainly CD8-exhausted cells lacking cytotoxicity, whereas dermal cells are mostly reactive cells exerting antitumor cytotoxicity. Tumor necrosis factor-alpha mediates hypopigmentation in both diseases and prevents disease progression. Repigmentation after nb-UVB in both diseases occurs before and independently from disappearance of the dermal infiltrate.

Inducible nitric oxide synthase promoter polymorphism: a molecular susceptibility marker for vitiligo in Egyptians.

BACKGROUND: Vitiligo is a depigmentary disease characterized by loss of melanocytes from the skin and mucous membranes. The pathomechanism of vitiligo is still obscure. Inducible nitric oxide synthase (iNOS) produces very large amounts of nitric oxide (NO). Promotor polymorphisms within iNOS gene have been reported to be associated with overproduction of NO, which may induce melanocyte destruction. AIM: The current study aimed at investigating the possible association between iNOS gene polymorphism (-954 G/C and Ex 16+14 C/T) and susceptibility to non-segmental vitiligo in a cohort of Egyptians. METHODS: The study was conducted on 200 participants: 100 patients with vitiligo and 100 aged matched healthy controls. Polymerase chain reaction using restriction fragment length polymorphism method (PCR-RFLP) was used to identify the genotypes. RESULTS: Our results showed that iNOS -954 G/C heteromutant genotype (GC) was associated with increased risk of vitiligo (OR = 3.35, 95% CI = 1.77-6.33), and the risk increased when confined to females (OR = 7.4, 95% CI = 2.80-19.40). iNOS Ex 16 + 14 C/T heteromutant genotype (CT) conferred two folds increased risk of vitiligo (OR = 2.47, 95% CI = 1.39-4.37). Furthermore, the risk of vitiligo increased when the heteromutant genotype of iNOS -954 G/C (GC) was co-inherited with the wild genotype of iNOS Ex16+14 C/T (CC) (OR = 23.2, 95% CI = 3.04-177.21). CONCLUSIONS: Inducible nitric oxide synthase -954 G/C and Ex 16+14 C/T might be considered as genetic susceptibility markers for non-segmental vitiligo among Egyptians.