P127 Cytokine gene Polymorphism in superficial Malassezia associated skin diseases
Authors: Jain Charu , Das Shukla , Ramachandran V.G , Saha Rumpa , Dar Sajad , Nirmal Kirti 
Published: September 2022

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PM

 

Objectives

ü To isolate and characterize Malassezia species from patients of Pityriasis Versicolor (PV), Atopic Dermatitis (AD), Seborrhoeic Dermatitis (SD), and healthy controls.

ü To study single nucleotide polymorphism in IL-10 and IFN- γ genes of the host and its relation with susceptibility to Malassezia infection.

Methods

It was a prospective observational study done in University College of Medical Sciences and GTB Hospital, Delhi. Sample size comprised of 38 cases each of AD. Skin scrapings were used for fungal culture on Sabouraud Dextrose Agar (SDA) and Modified Dixon Agar (MDA) and isolates were identified as per conventional phenotypic methods. Genomic DNA was extracted from blood samples and Cytokine genotyping was carried out by Amplification Refractory Mutations System-Polymerase Chain Reaction (ARMS-PCR) with sequence-specific primers. Three SNPs (IL10-1082A/G; IL10-819/592C/T; IFN-g +874A/T) in two cytokine genes were assessed in all the patients and healthy controls. Chi-squared Test or Fisher's-Exact Test and Bonferroni's correction were used for statistical analysis

Results

Malassezia yeast was isolated in 94.7%, 63.1% each and 52.6% in PV, AD, SD, and healthy controls respectively. Malassezia globosa was the most commonly isolated species from both patient and healthy control. Malassezia sympodialis was the second most common followed by M. furfur and M. restricta. Association between specific cytokine gene polymorphism and clinical outcome was found to be significant in PV, AD, and SD group. IFN-γ +874 T allele and IFN-γ +874 A allele were significantly associated with PV and AD respectively. IFN-γ +874 AA genotype frequency was found to be higher in PV and AD patients than in controls. This finding suggests that PV and AD patients may produce a lower IFN-γ. IL10-819/592 C/T alleles were also significantly associated with PV. IL10-819/592 CT genotype frequency was found to be lower, and CC genotype frequency was found to be higher in PV patients as compared to healthy controls, suggesting that IL10 production may be higher in PV patients. AD patients were more likely to carry the IL10–1082 G allele and, it was significantly associated with this disease. Moreover, IL10-1082 AG genotype was significantly associated with AD and SD, which corresponds to high production of IL10.

Conclusion

The identification of Malassezia yeast to a species level is of a great importance to determine which species are implicated in certain skin diseases.

The use of phenotypic methods for identification of Malassezia species is a reliable, easily executed method, that is also inexpensive. Molecular methods are necessary to decrease the turnaround time, especially for slow-growing Malassezia species.

Cytokine gene polymorphism studies in IL10 and IFN γ genes demonstrated susceptibility of host to Malassezia infections. Comparison with the serum cytokine levels will help in understanding the evolution of Malassezia infections in susceptible host.

Population genetics studies require inclusion of a larger number of subjects to evaluate the probability or the frequency of occurrence of the genotype.