Perfil do estresse oxidativo na lesão renal de pacientes com lúpus eritematoso sistêmico

Abstract

Systemic Lupus Erythematosus (SLE) is an autoimmune disease of connective tissue, with etiology and pathogenesis still not fully understood. Among the most important clinical manifestations of SLE is the lupus nephritis (LN), characterized as a serious risk factor for morbidity and mortality, which during the periods of exacerbation occurs the production of autoantibodies and immune complex deposition in glomeruli, favoring the production of reactive oxygen species, which may act as mediators of glomerular damage. To better evaluate the profile of oxidative stress in renal injury in patients with SLE, 93 patients were selected, aged between 15 and 49 years, distributed between the groups: control lupus (n = 30), lupus nephritis (n = 31), and active lupus without kidney injury (n = 21) and without lupus (n = 11), to carry out a cross-sectional study whose blood samples collected were subjected to hematologic (complete hemogram), biochemistry (urea, creatinine, uric acid, total protein and albumin), immunological (complement C3 and C4) and oxidative stress markers (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), total thiol (SH), malondialdehyde (MDA), total oxidant status (TOS), total antioxidant capacity (TAC), index oxidative stress (IEO) and allantoin) dosages. The GPx activity showed increased in SLE control, GR activity showed increased in active SLE without renal injury, the SH concentration showed decreased in NL and active SLE without renal injury, the concentration of MDA showed elevated in active SLE without renal injury, TOS levels showed decreased in the NL, the TAC levels showed increased in the NL, the IEO determination showed decreased in NL and allantoin levels showed increased in patients with SLE (control and activity). SLEDAI score showed positively correlated with GR and negatively with GPx and MDA, TOS, IEO and SH. Prednisone showed positively correlated with GR and negatively with TOS, IEO and SH. Urea showed positively correlated with GR and allantoin and negatively with SH. Creatinine showed positively correlated with TAC and allantoin and negatively with TOS, IEO and SH. Total proteins showed positively correlated with TOS, IEO, SH and negatively with MDA and TAC and allantoin. Albumin showed positively correlated with GPx, TOS, and IEO SH and negatively with allantoin. Uric acid showed positively correlated with allantoin and negatively with SH. C3 showed positively correlated with SH and negatively with GR. SLE patients, regardless of the target organ and in any degree of disease activity had alterations in oxidative stress, possibly due to a high consumption of endogenous antioxidants and reduced antioxidant enzyme activity. Further studies may deepen the knowledge about the possible benefits of antioxidants inclusion in the treatment protocol of this disease.