Renal comorbidity in psoriatic arthritis patients

Abstract

Introduction. Psoriatic arthritis (PA) is a multi-system inflammatory disorder that involves both musculoskeletal structures (joints, enthesis, tendons) and the skin and nails (psoriasis). Clinical manifestations can be varied from clinically asymptomatic disease to arthritis mutilans and invalidating forms.Purpose. Identification of renal disease in patients with psoriatic arthritis depending on the degree of activity and severity of skin and joint disease.Material and Methods. We conducted a retrospective study of 89 patients diagnosed with psoriatic arthritis in the Rheumatology Department of Clinical Emergency Hospital “Sf. Andrei” in Constanta. We collected demographic and behavioural data (age, sex, ethnicity, smoking), clinical and biological elements of joint and skin disease activity (number of painful and swollen joints, joint pain score - VAS, PASI score, ESR, CRP) and evaluation of renal function (serum creatinine, serum uric acid, urinalysis examination for proteinuria and hematuria). Chronic kidney disease was staged by calculating the value of glomerular filtration rate (GFR) with CKD-EPI 2009 equation.Results. 49 patients have full screening of renal function, especially in disease onset or in case of therapy switch. Proteinuria was found in a significant percentage of patients (32.65%), vary widely between 10-500 mg/dL. Chronic kidney disease (CKD) was commonly found in our patients (42.85%), mostly in women (66.6%). Most cases of CKD were in stage 2 (12.4%). We observed a significant correlation between age and levels of serum creatinine (p = 0.041), caucasians developing more frequently CKD (p <0.0001). The presence of skin psoriasis did not interfere with renal function decline in PA patients, but its severity, measured with PASI score, was correlated with cronic kidney failure stages (p = 0.05) and proteinuria (p = 0.044). The severity of joint pain (TJC, VAS) is directly related to kidney disease (p <0.0001, respectively p = 0.05). The majority of patients with extensive joint erosions also had renal impairment (p = NS) and it can be seen a direct correlation between erosive joint disease and serum creatinine (p = 0.029).Conclusions: Both the severity of psoriasis and articular disease may be involved in worsening of renal function, probably due to the chronic systemic inflammation and to an aggressive therapy imposed by the disease evolution.