Abstract. Systemic lupus erythematosus (SLE) is a chronic autoimmune disease that affects almost all internal organs, among which damage to the organs of the circulatory system (OSC) is not only one of the most common, but also ranks first in the structure of the causes of mortality.
 The aim of the study. To find out the prognostic value of diagnostically valuable laboratory markers of systemic lupus erythematosus to determine the probability of comorbid syntropic lesions of the circulatory system organs.
 Materials and methods. The study included 125 patients with SLE with OSC lesions, among whom the vast majority of women (88.00%) were young (average age of patients 42.48 ±1.12 years). Patients were stratified according to the presence of comorbid syntropic lesions of the OSC, i.e. those whose frequency reliably increased with an increase in the degree of activity of SLE – these are retinal angiopathy, capillaritis, Raynaud's syndrome, reticular livedo, atherosclerosis, mitral valve insufficiency, mitral valve sealing, pericardial effusion, pulmonary hypertension, myocarditis, endocarditis, symptomatic arterial hypertension, venous thrombosis. During the study, the prognostic value of diagnostically valuable individual laboratory markers and their constellations was determined. The difference was considered statistically significant if p < 0.050. The relationship was considered confirmed if the association coefficient ≥ 0.50 or the contingency coefficient ≥ 0.30.
 The results. It was found that for determining the probability of retinal angiopathy in patients with SLE, the constellation with ↑ LDL + ↑ IA + ↑ anti-ds DNA + ↑ ANA has the best prognostic value among diagnostically valuable individual laboratory markers and their constellations; for capillaritis – a separate marker of increased activity of AlT; for Raynaud's syndrome – a separate marker ↓ C3; for reticular livedo – ↑ ESR + ↑ small CIC + ↑ anti-ds DNA + ↑ anti-Sm; for atherosclerosis – ↓ hemoglobin + ↑ LDL + ↑ ANA + ↓ C4; for mitral valve insufficiency – ↑ ESR + ↑ anti-ds DNA + ↑ ANA + ↑ antiphospholipid antibodies Ig M; for mitral valve sealing – ↑ ESR + ↑ LDL + ↑ small CIC + ↑ ANA; for pericardial effusion – erythropenia + ↑ C-RP + ↑ lupus anticoagulant; for pulmonary hypertension – hypercholesterolemia + ↑ LDL + ↑ anti-ds DNA + ↑ ANA; for myocarditis – a separate marker ↓ C4; for endocarditis – not detected; for symptomatic hypertension – ↑ LDL + ↑ anti-ds DNA + ↑ ANA + ↑ anti-SSA (Ro); for venous thrombosis – erythropenia + ↓ hemoglobin + ↑ LDL + ↑ ANA.
 Conclusions. For each comorbid syntropic lesion of the organs of the circulatory system in patients with systemic lupus erythematosus, a diagnostically valuable separate laboratory marker or their constellation has been determined, which have the best prognostic value for determining the probability of occurrence of these lesions.