Evaluation of histopatologic and immunphenotype features of mycosisfungoides and comparing them with apoptotic and antiapoptotic genes before and after PUVA treatment

Mycosis fungoides is the most common cutaneous lymphoma. Theetiopathogenesis is not still completely understood. The characteristically slowprogression of the lesions have lead to the hypothesis that MF originates from anaccumulation of lymphocytes due to defective apoptosis of skin homing Tlymphocytes. The diagnosis of early stage MF lesions is quite difficult and anumber of histopathological criteria have been suggested for correct diagnosis.Immunohistochemical and molecular genetical researches have been proposed assupportive methods to help confirmation. No definite criteria for the diagnosis ofearly and limited stage of MF have been constituted up to date. In our study weaimed to clarify the etiopathogenesis of MF, the mechanism of PUVA treatmentand to determine the validity of the diagnostic criteria in the early stage of MF.In our study 20 MF patients who had received PUVA treatment wereincluded. 20 patients with benign inflammatory dermatosis (10 lichen planus,10psoriasis vulgaris) were considered as the control group.First paraffin sections were stained with hematoxylin and eosin and theslides were evaluated according to the recent published histological criteria for thedifferentiation of early lesions of MF. There after CD3, CD4, CD7, CD8, CD20,p53, Bcl-2, FasL and caspase-3 proteins were immunohistochemically stained andexpression of the proteins was quantified in terms of staining grade andpercentage. The staining grade and percentage of p53, Bcl-2, FasL and caspase-3proteins before treatment were compared with the after treatment as well as thecontrol group. Also histopathological and immunophenotypical characteristics ofMF patients before treatment were compared with these proteins.In the MF group epidermotropism was detected in %100 of patients.CD3(+), CD4(+), CD7(-), CD8(+) and CD20(+) lymphocytes were seen in %75,%30, %50, %70 and %20 of the patients respectively. Positive immunostaining ofp53 was not detected in neither MF nor the control group. There was nostatistically significant difference between immunstaining grade and percentage ofBcl-2 and FasL before and after treatment of the MF group (p>0.05), but thedifference was statistically significant for caspase-3 (p<0.05). Immunostaininggrade and percentage of Bcl-2 and FasL of the control group were found to behigher than the MF group before treatment, and this was also statisticallysignificant (p<0.05). No statistically significant difference of the immunostaininggrade and percentage of caspase-3 was found in MF patients before treatment andcontrol group (p>0.05). Any association between positive immunostaining ofcaspase-3 and histopathological and immunphenotypical features were notdetermined (p>0.05).Our results revealed that a variety of histopathological patterns can be seenin early MF lesions and the evaluation of immunphenotypical features can help toconfirm the diagnosis. We also concluded that the expression of apoptotic andantiapoptotic genes in the early stage MF patients was rare, and PUVA shows itseffect by acting on an antiapoptotic gene; caspase- 3.