Background Generalized pustular psoriasis (GPP) is a chronic disease associated with genetic factors related to mutations of the interleukin 36 receptor antagonist gene (IL36RN) and the caspase recruitment domain 14 gene (CARD14). However, the relevance of these mutations to the clinical features and severity of GPP remains unclear. Aims Our objective was to correlate the presence of IL36RN and CARD14 mutations with the clinical and laboratory findings in patients with GPP. Methods This cross-sectional descriptive study was conducted in 64 subjects with GPP. Clinical manifestations were recorded and the severity was graded as mild, moderate, or severe. Routine laboratory tests were performed and blood samples were collected for Sanger sequencing. The clinical data of patients were compared among the different mutation groups. Results The two main variants of IL36RN were c.115+6T > C (p.Arg10ArgfsX1) and c.227C > T (p.Pro76Leu). The major CARD14 mutations were c.2458C > T (p.Arg820Trp), c.1641C > T (p.Arg547Ser), and c.1753G > A transitions. Provocative factors were uncommon in the group with both IL36RN and CARD14 mutations. Drugs (unspecified), especially herbals, were the most common triggers. A history of psoriasis was frequent in patients with only CARD14 mutations, but fever was uncommon. The c.1641C > T mutation was associated with leukocytosis > 15000/mm3 and the c.1753G > A mutation was associated with hypoalbuminemia <3.8g/dL. Both the c.115+6T > C and c.227C > T variants of IL36RN were associated with fever ≥38.5°C while the c.115+6T > C variant was also associated with geographic tongue. No gene mutations were associated with the total severity and severity grades. Limitations Four patients without the two major IL36RN mutations were excluded from the study. Conclusion The presence of IL36RN and CARD14 mutations were associated with a history of psoriasis, various provocative factors, fever, leukocytosis, hypoalbuminemia, and geographic tongue. Further studies to explore the role of these mutations in therapeutic efficacy and disease outcomes are necessary.
Keywords: CARD14; Gene mutation; IL36RN; generalized pustular psoriasis.