AFF1 and STAT4 genes polymorphism in Egyptian systemic lupus erythematosus patients: Association with disease development and activity

Aim of the work: To assess the possible association of ALF transcription elongation factor 1 (AFF1)(rs340630) and signal transducer and activator of transcription 4 (STAT4)(rs7582694) genes polymorphism in Egyptian systemic lupus erythematosus (SLE) cases and their relation with disease activity. Patients and methods: The study included 103 SLE patients and 103 matched controls. SLE disease activity index (SLEDAI-2 K) was assessed. Genotyping was implemented with amplification refractory mutation system polymerase chain reaction (PCR) for AFF1 and allele-specific multiplex PCR for STAT4. Results: The median age of the patients was 38 years, disease duration was 7 years and were 97 females and 6 males (F:M 16.2:1). The median SLEDAI-2 K was 5. AFF1 ‘G’ allele was associated with SLE at 1.52 higher odds ratio (p = 0.042). AFF1 genotypes showed no significant association with existence of SLE (p = 0.08). In SLE patients with A/A genotype, seizures (28.6 %), pleurisy (42.9 %), consumed C3 (85.7 %) and consumed C4 (71.4 %) was significantly more frequent compared to G/A (5.7 %,7.5 %, 56.6 % and 39.6 %) and G/G (0 %, 9.3 %, 39.5 % and 14 % respectively; p = 0.01,p = 0.046,p = 0.04 and p = 0.001). There was a significant association between STAT4 gene polymorphism and the 'C' allele with the occurrence of SLE (p = 0.005 and p < 0.001 respectively). No significant difference was found in clinical manifestations, laboratory investigations or disease activity among STAT4 genotypes. Conclusion: STAT4 polymorphism revealed a significant association with increased SLE risk. However, AFF1 ‘polymorphism showed no significant association with existence of SLE. No significant difference was found in the proportions of AFF1 and STAT4 genotypes among activity grades of SLE.