Ana Cristina Biral

Human leukocyte antigen (HLA) and single nucleotide polymorphisms (SNPs) tumor necrosis factor (TNF)‐alpha ‐238 and ‐308 as genetic markers of susceptibility to psoriasis and severity of the disease in a long‐term follow‐up Brazilian study

Background  The strongest genetic marker for psoriasis is Cw*06. Polymorphisms in the tumor necrosis factor (TNF)‐alpha promoter region, especially replacement of guanine with adenine in positions ‐238 and ‐308 are related to higher TNF‐alpha production and higher risk for psoriasis in Caucasoid populations, not found in Asians. We performed a case‐control study of 69 patients with psoriasis type I and 70 controls, characterized clinical progression along 10‐years of follow‐up in mild or severe disease and determined HLA class I, II, and TNF single nucleotide polymorphisms (SNPs) ‐238 and ‐308 polymorphisms to demonstrate whether these polymorphisms may be genetic risk for susceptibility to psoriasis or severity of the disease in Brazilians.

HLA-G Expression in the Skin of Patients with Systemic Sclerosis

Objective. To determine HLA-G expression in skin biopsies from patients with systemic sclerosis (SSc), and its association with epidemiological, clinical, and laboratory variables and survival. Methods. Paraffin-embedded skin biopsies obtained from 21 SSc patients (14 limited SSc, 7 diffuse SSc) and from 28 healthy controls were studied. HLA-G expression was evaluated by immunohistochemistry. Results. HLA-G molecules were detected in 57% of skin biopsies from patients with SSc (9 from limited SSc, 3 from diffuse SSc), whereas no control sample expressed HLA-G (p = 0.000004). In patients, HLA-G molecules were consistently observed within epidermal and some dermal cells. HLA-G expression was associated with a lower frequency of vascular cutaneous ulcers (p = 0.0004), telangiectasias (p = 0.008), and inflammatory polyarthralgia (p = 0.02). After a 15-year followup, SSc patients who exhibited HLA-G survived longer than patients who did not. Conclusion. HLA-G is expressed in skin biopsies from patients with SSc, and this is associated with a better disease prognosis. This suggests a modulatory role of HLA-G in SSc, as observed in other skin disorders.