A Comprehensive Study of Tumor Necrosis Factor-Alpha Genetic Polymorphisms, its Expression in Skin and Relation to Histopathological Features in Psoriasis.
BACKGROUND
Tumor necrosis factor-alpha (TNFα) is an important inflammatory mediator in psoriasis and several genetic polymorphisms of this cytokine have been reported. Majority of studies have focused on the increased G- A polymorphism at the -308 position in psoriasis. There has been no comprehensive study evaluating the genetic polymorphisms, TNFα expression in the skin and histopathology. We are undertaking this study to outline TNFα genetic polymorphisms, its skin expression and histopathological correlation to help determine its role at the genetic and protein level.


METHODS
112 patients of psoriasis and 243 healthy controls were included in this prospective study. 5 ml of peripheral blood was collected to study the TNFα genetic polymorphisms by polymerase chain reaction and restriction fragment length polymorphism analysis. Histopathological analysis of biopsies from the 112 patients were done using visual analogue scale and correlated with the findings. 61 of these cases were analyzed for TNFα expression by immunohistochemistry. The results of study were statistically analyzed using SPSS 13.0 statistical package program.


RESULTS
A strong association of TNFα -308 G/A polymorphism in psoriasis cases was detected. The A allele of the TNFα -308 G/A polymorphism occurs rarely in the Indian population, however there is an over representation of this allele in psoriatic patients. There was no association seen between TNFα genotype and histopathological severity of psoriasis.


CONCLUSIONS
The study emphasized the central role of TNFα in the pathogenesis of psoriasis. TNFα genotyping may be helpful in identifying subjects in whom anti-TNFα therapeutic strategies may be tried.
Department of Pathology, Armed Forces Medical College and Command Hospital, Pune, Maharashtra, India.
Nikhil N
NN
Moorchung
Department of Dermatology, Armed Forces Medical College and Command Hospital, Pune, Maharashtra, India.
Biju
B
Vasudevan
Department of Dermatology, Armed Forces Medical College and Command Hospital, Pune, Maharashtra, India.
Manas
M
Chatterjee
Department of Dermatology, Armed Forces Medical College and Command Hospital, Pune, Maharashtra, India.
Rajan Singh
RS
Grewal
Department of Pathology, Armed Forces Medical College and Command Hospital, Pune, Maharashtra, India.
Narayana S
NS
Mani
Genetic polymorphisms; histopathology; psoriasis; tumour necrosis factor-alpha