TISSUE OXYGEN SUPPLY IN PATIENTS WITH SYSTEMIC LUPUS ERYTHEMATOSUS

Iaremenko O.B., Dzhus M.B. , Karasevska T.A.

• Bogomolets National Medical University, Kyiv

Summary. One of the main reasons for the uncertainty of indications and effectiveness criteria of non-specific systemic lupus erythematosus (SLE) treatment methods is the absence of a common denominator that would reflect the state of nonspecific reactions of the body to the pathological process in all patients. The parameters of the human body oxygen supply, the mechanisms of tissue hypoxia or normoxia formation could potentially serve this role. Objectives. To investigate the state of body oxygen supply in patients with SLE and its association with disease activity, renal involvement and glucocorticoid (GC) treatment. Materials and methods. A total of 108 patients with SLE were examined, including those with low (n=30), moderate (n=38) and high disease activity (n=40) according to SLEDAI-2K score. We assessed pulmonary gas exchange using mass spectrometry and spirometry, oxygenation parameters of arterial and venous blood (femoral vessels), P50 value, calf blood flow, subcutaneous calf tissue oxygen tension and kinetic parameters of its delivery and utilization using polarographic method. Results. In patients with SLE, disruptions in oxygen transport were observed at all stages. However, the key determinants of tissue oxygen regime (TOR) were the rate of capillary-tissue oxygen diffusion (CTOD), tissue respiration activity (TRA) and the state of microhemodynamics. A common pattern in more severe categories of patients (GC-naive, high disease activity) was the presence of normal or elevated TRA and CTOD, along with arteriovenous blood shunting activation. Low disease activity and GC use were associated with decreased TRA and CTOD. Patients with nephritis exhibited the unique feature of substantial arterial blood oxygen undersaturation due to more pronounced anemia, which was compensated by increased peripheral blood flow. Conclusions. The TOR parameters may serve as immune-independent criteria for assessing systemic changes in tissues and as indicators of adaptive mechanism activation.