Functional reserve of oxygen-dependent metabolism of phagocytes in blood of patients with severe hemorrhagic fever with renal syndrome complicated by acute renal failure

INTRODUCTION: Hemorrhagic fever with renal syndrome (HFRS) is one of the most common zoonotic infections, and acute renal failure (ARF) is a serious complication of HFRS. A mechanism inalienable from the pathogenesis of HFRS is activation of oxygen-dependent metabolism of phagocytes and the generation of reactive oxygen species (ROS) by them. Overactivation of oxygen-dependent processes induces oxidative damage to molecular structures and underlies the development of ARF leading to marked alterations of reserve capacities of phagocytes.

AIM: Evaluation of the functional reserve of oxygen-dependent metabolism of phagocytes in the blood of patients with severe HFRS complicated by ARF.

MATERIALS AND METHODS: The study included 140 patients who underwent treatment at the Republican Clinical Infectious Diseases Hospital in Ufa. Thirty-two patients had mild form of HFRS, 35 patients had moderately severe form, 35 patients had severe HFRS and 38 patients had severe HFRS complicated by ARF. The comparison group consisted of 46 healthy individuals. Parameters of spontaneous and induced oxygen-dependent metabolism of phagocytes, generation by them of ROS, were evaluated by registration of luminol-dependent chemiluminescence (LDCL). On the basis of these parameters, the functional reserve of oxygen-dependent metabolism of phagocytes was calculated using the formula that estimated the multiplicity of the difference between spontaneous and induced LDCL to spontaneous LDCL.

RESULTS: The functional reserve did not change in mild HFRS, but decreased in moderate and severe forms. The reserve was better preserved in patients with moderately severe disease (2.8) compared to severe form (2.0; р < 0.05). The greatest drop in the functional reserve (0.7) was recorded in patients with severe HFRS complicated by ARF, which was accompanied by increased spontaneous oxygen-dependent metabolism (5.1 times the control) and twice reduction of induced metabolism from the control (р < 0.05). Thus, the drop of the functional reserve of phagocytes increased with increase in severity of HFRS: in patients with moderate and severe HFRS without ARF, the drop was up to 30.0%, while with ARF complication — 65.0% (р < 0.05).

CONCLUSION: A decrease in the reserve of functional activity of phagocytes in patients with HFRS with clinical symptoms of ARF indicates a breakdown of adaptive capacities of an organism, a decrease in its protective immunoregulatory capacities. The parameters of the functional reserve can be considered a marker of severe LFRS complicated by ARF.