The article presents the data of current publications on the problem of respiratory lesions in immune-mediated inflammatory rheumatic diseases and the results of our own studies on the frequency and spectrum of bronchopulmonary pathology in patients with rheumatoid arthritis (RA), ankylosing spondylitis (AS), systemic connective tissue diseases, and ANCA vasculitis. Respiratory system lesions are detected in 24.5–70.2 % of patients with inflammatory RD according to different authors. Interstitial lung diseases, pulmonary fibrosis, and bronchial obstruction prevail in the structure of respiratory disorders. Polymorphism of pulmonary manifestations of RD includes pulmonary hypertension, which is recorded in more than a third of patients with systemic connective tissue diseases. As our own clinical data showed, respiratory lesions occurred in 33 people (27.5 %) out of 120 patients with immune-mediated inflammatory RD. The leading form of damage was interstitial pneumonia and interstitial pulmonary fibrosis. Among the patients with determined lung involvement were individuals with RA, SSc, ANCA vasculitis, AS and Sjogren's disease. The article presents a clinical case of the interstitial pneumonia in a patient with RA. The contribution of uncontrolled rheumatoid inflammation and disease-modifying therapy to the manifestation of pulmonary involvement is discussed. The positive effect of IL-6 inhibitor in abolishing RA activity and pulmonary lesion is shown.

   In recent years, there has been a growing interest in the use of biologically active additives (BAA) in the comprehensive management of gout, thereby opening new avenues for both patients and healthcare providers. Gout, as a metabolic disorder, necessitates not only traditional pharmacological interventions but also additional strategies for managing serum uric acid (SUA) levels. BAAs may serve as an important adjunct to existing medical therapies, enabling the reduction of hyperuricemia, the frequency of arthritis flare-ups, and the improvement of patients' quality of life. Research indicates that components of BAAs can modulate inflammatory responses and exhibit diuretic effects, which is particularly relevant for patients with urate nephropathy. However, despite promising results, further clinical trials are required to confirm their safety and efficacy. It is important to note that the integration of BAAs into standard therapy necessitates a careful analysis of interactions with other medications. We are on the brink of a new era in gout treatment, and BAAs may occupy a significant position in this transformation.

   Aim: to study the association between bone mineral density (BMD) and uric acid (UA) level in postmenopausal women.

   Materials and methods. 263 women were examined (median age 62 [56; 67] years). A clinical examination and assessment of UA level were performed. Dual-energy X-ray absorptiometry was done to assess BMD in standard regions of interest (ROI): lumbar spine (L1-L4), femoral neck (FB) and total hip (TH) and trabecular bone score (TBS).

   Results. The frequency of hyperuricemia in postmenopausal women was 12.5 %, and in persons with osteoporosis (OP) – 10.1 %. UA correlated significantly with BMD and T-score in L1-L4 (r = 0.20 and r = 0.19, respectively) and TH (r = 0.18 and r = 0.16, respectively). No correlation was found between UA and TBS value (p > 0.05). Linear regression analysis adjusted for age showed a significant association between UA and BMD in all ROI (b*L1-L4 = 0.21, p = 0.001; b*FN = 0.14, p = 0.024; b*TH = 0.20, p = 0.002). In women with UA level ≥ 200 mmol/l, the BMD and T-score in all ROI were significantly higher, and the frequency of OP was lower compared with women with UA < 200 mmol/l (p < 0.05 for all comparison).

   Conclusion. Hyperuricemia was found in 12.5 % of postmenopausal women, and in 10.1 % of patients with OP. Significant differences in BMD, T-score, and OP frequency were found in all ROI, depending on the UA level. The mean value of TBS and the frequency of degraded bone microarchitecture did not differ depending on the UA level.

   The concept of post-COVID syndrome (PCS) as an independent nosological entity underlies the search for criteria for establishing this diagnosis. To date, there is an idea of two clinical phenotypes of the post-COVID state, occurring with different pathogenetic mechanisms. One of them is probably the consequences of damage to organs and systems and / or iatrogenic factors suffered during COVID-19. The pathogenesis of the other is not entirely clear, and the clinical manifestations are like those of a number of dysfunctional pain disorders, such as fibromyalgia (FM) and chronic fatigue syndrome / myalgic encephalomyelitis. The article is devoted to the analysis of literary data indicating the similarity of PCS and FM. The need to revise the diagnostic criteria for PCS is substantiated.

   Introduction. Osteoarthritis (OA) of the knee joints is the most common joint disease affecting more than 80 % of people over 55 years of age. The priority method of treatment of knee joint OA is considered to be local injection therapy with the introduction of synovial fluid endoprostheses based on hyaluronic acid, included in the second stage of the ESCEO algorithm in 2019, as well as in the standard of specialized medical care for gonarthrosis (Order of the Ministry of Health No. 706n dated 10/27/2022). In world practice, joint fluid prostheses containing hyaluronic acid at a concentration of 10 mg/ml, 15 mg/ml, 23 mg/ml.

   The purpose of the study: to compare the effectiveness of the outpatient use of hyaluronic acid «Sintesin» 1 % - 2.0 ml, «Sintesin Plus» 1.5 % - 2.0 ml, «Sintesin Forte» 2.3 % - 3.0 ml (Bionoltra SA, Switzerland) together with the oral use of selective nonsteroidal anti-inflammatory drugs (NSAIDs) in patients with osteoarthritis (OA) of the knee joint of stage I–III.

   Materials and methods. A comparative observational study of the efficacy and safety of injection therapy with the introduction of hyaluronic acid preparations included 120 patients with knee joint OA of the 1^st-3^rd stage who had not previously received treatment with the original drug «Sintesin» 1 % - 2.0 ml, «Sintesin Plus» 1.5 % - 2.0 ml, «Sintesin Forte» 2.3 % - 3.0 ml (Bionoltra SA, Switzerland). The selection of drugs for the treatment of patients with knee joint OA of the 1st-3rd stage was carried out in accordance with clinical recommendations for the treatment of osteoarthritis, taking into account the age and comorbidity of patients, as well as taking into account the accepted Consensus on the use of hyaluronic acid preparations (Congress of Orthobiology 2024). Celecoxib 200 mg per standard nonsteroidal anti-inflammatory drugs was selected the dosage is 200 mg / day for a period of 8 days to 1 month. Group A (30 people) – local administration of «Sintesin» 1 % - 2.0 hyaluronic acid by 3 injections into the joint – 1 time per week. Group B (30 people) – local administration of «Sintesin Plus» 1.5 % - 2.0 hyaluronic acid by 2 injections into the joint, 1 time per week. Group C (30 people) – local administration of «Sintesin Forte» 2.3 % - 3.0 – hyaluronic acid once. All patients were prescribed celecoxib 200–400 mg per day. Comparison group D (30 patients with stage I–III knee OA without synovitis) received only NSAIDs (celecoxib 200–400 mg per day). The duration of therapy with Celecoxib 200–400 mg per day in all groups ranged from 8 days to 1 month (according to indications, depending on the intensity of the pain syndrome). The total duration of follow-up was 6 months, the frequency of visits was 30, 90 and 180 days. The results were evaluated using standard examination methods., The pain level was assessed on a visual analog scale, based on the results of a patient survey, the WOMAC functional index and the Leken index were determined.

   Results. In group A (30 patients with stage I–III OA of the knee joint without synovitis, received intraarticular «Sintesin» 1 % - 2.0 3 injections into the joint – 1 time per week) – pain reduction was revealed on the 7^th day, NSAIDs were canceled on the 8^th day at stage I–II and on the 21^st a day at stage 3 (hereinafter NSAIDs – «on demand»). After 6 months, the pain in YOUR body decreased to 20–25 mm in OA of the knee joint of stage I–II and to 35–40 mm in stage III, a decrease in the Leken index after 6 months to 4 and 6–7 points, respectively. In group B (30 patients with stage I–III OA of the knee joint without synovitis, received intraarticular «Sintesin Plus» 1.5 % - 2.0 2 injections into the joint, 1 time per week) – pain reduction was revealed – NSAIDs were canceled on day 6 at stage 1–2, and on day 15 at stage 3 OA of the knee joint. Your pain decreased after 6 months to 20–25 mm in stage I–II knee joint OA and to 35–40 mm in stage III (NSAID was canceled after 14 days, then – «on demand»), a decrease in the Leken index after 6 months up to 4 and 5–6 points, respectively. In group C (30 patients with stage I–III OA of the knee joint without synovitis, received intraarticular «Synthesin Forte» 2.3 % - 3.0 once) – pain reduction was revealed on 3–4 days at stage 1–2 (NSAIDs were canceled on day 4) and on the 10^th day at stage 3 OA of the knee joint. Your pain decreased after 6 months to 15 mm in stage I–II knee joint OA and to 30 mm in stage III (NSAID was canceled after 10 days, then – «on demand»), the Leken index decreased after 6 months to 3 and 5 points, respectively. In group D (30 patients with stage I–III knee OA without synovitis, received only NSAIDs (celecoxib 200 mg per day). Pain reduction was revealed on the 10^th day (NSAID was canceled on the 11th day) at stage I–II and on the 25^th day at stage 3 (hereinafter NSAIDs – «on demand»). After 6 months, the pain in YOUR body decreased to 35 mm in OA of the knee joint of stage I–II and to 65 mm in stage III, a decrease in the Leken index after 6 months to 5–6 and 10–12 points, accordingly.

   Conclusions. 1. Preparations of hyaluronic acid «Sintesin» 1 % - 2.0, «Sintesin Plus» 1.5 % - 2.0, «Sintesin Forte» 2.3 % - 3.0 (produced by Bionoltra SA, Switzerland) – can be used as a safe and effective synovial fluid endoprosthesis in stage I–III OA of the knee joint with insufficient effect from chondroprotectors and NSAIDs. 2. It is recommended to use the identified advantages and possibilities of local injection therapy with hyaluronic acid «Sintesin» of various concentrations on an outpatient basis at all stages of knee joint OA. 3. Local injection therapy with hyaluronic acid «Sintesin» in combination with a short course of selective NSAIDs is recommended as the preferred treatment method in comparison with the appointment of only one selective NSAID.

   Osteoporosis is the fourth most common disease in the world among people over 50 years old, and its social significance is associated with low-energy vertebrae and nonvertebrae fractures, leading not only to a deterioration in the patient’s quality of life, which may not return to the pre-fracture level for many years, but also to an increase in mortality. Currently, in real clinical practice, the diagnosis of osteoporosis continues to be based on measuring bone mineral density using dual-energy X-ray absorptiometry, while this type of equipment often remains unavailable in certain regions of our country. The article discusses the clinical criteria for the diagnosis of osteoporosis, provides mandatory and, if necessary, additional laboratory tests for patients, as well as recommendations for choosing an anti-osteoporotic medication. Special attention is paid to the need for additional intake of calcium and vitamin D in combination with all medications used to treat osteoporosis.

   The relationship between serum levels of vitamin D and uric acid (UA) in the blood may be bidirectional, yet remains unexplored in patients with gout.

   The aim of this study was to identify the association between serum levels of UA and vitamin D deficiency in patients with gout.

   Materials and Methods. This single-center observational study included 79 patients with a confirmed diagnosis of gout (72 [91.1 %] men and 7 [8.9 %] women) who were not receiving urate-lowering therapy (ULT). All patients underwent evaluation of uric acid (UA), vitamin D, parathyroid hormone, C-reactive protein (СRP), creatinine, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and serum calcium levels, alongside calculating the estimated glomerular filtration rate (eGFR). The levels of vitamin D and the frequency of vitamin D deficiency were compared across groups with different levels of UA in blood (quartiles): <426 µmol/L, 427 to 479 µmol/L, 480 to 540 µmol/L, and ≥ 540 µmol/L.

   Results. The mean level of vitamin D was below the normal reference values, at 22 (17–27) ng/mL (Median). Among the patients, 63 (80 %) exhibited vitamin D levels indicative of deficiency (< 30 ng/mL). A moderate correlation was found between vitamin D levels and serum calcium (ρ = 0.343, p = 0.002), while weak correlations were also noted between vitamin D levels and CRP (ρ = –0.204, p = 0.071) as well as parathyroid hormone (ρ = –0.216, p = 0.056). The levels of uric acid were categorized into quartiles: < 426 µmol/L, 427 to 479 µmol/L, 480 to 540 µmol/L, and ≥ 540 µmol/L. The analysis of vitamin D levels among different quartiles of UA revealed no significant relationship (p = 0.672).

   Conclusions. Vitamin D deficiency is prevalent in the majority of patients with gout (80 %); however, the severity of hyperuricemia is not associated with serum vitamin D levels. Further investigations are required to identify the causes of the high frequency of vitamin D deficiency in patients with gout.

   Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease of unknown etiology with heterogeneous clinical manifestations. One third of patients with SLE have various ophthalmologic symptoms. Eye lesions may be the initial signs of SLE and lead to severe complications, including vision loss. Ophthalmologic manifestations are often associated with the degree of activity of systemic inflammation. Dry keratoconjunctivitis, or secondary Sjogren's syndrome, is the most common ophthalmologic manifestation of SLE. Episcleritis and scleritis are less common, but they can be the first signs of SLE. Unilateral or more often bilateral retinopathy associated with retinal vasculitis can cause visual loss of varying severity. A number of adverse ophthalmologic events occur on the background of long-term use of drugs used currently for the treatment of SLE: posterior subcapsular cataract and secondary open-angle glaucoma when using glucocorticosteroids, retinopathies – in cases of long-term use of hydroxychloroquine. The side effects of other immunosuppressive and biological agents are still poorly understood. Regular ophthalmologic examinations are recommended for all patients with SLE.

   Spondyloarthritis is a group of diseases involving the axial skeleton and sacroiliac joints, including axial spondyloarthritis or ankylosing spondylitis and peripheral spondyloarthritis. Spondyloarthritis is associated with an increase in cardiovascular morbidity and mortality, which may be the result of cardiac manifestations of disease or due to the accelerated development of atherosclerosis. The combination of two pathologies contributes to a more severe course of diseases and negatively affects the results of therapy, which indicates the relevance of this interdisciplinary problem. The review highlights data on cardiovascular morbidity and mortality in spondyloarthritis, the occurrence of various risk factors. The data on the relationship of cardiovascular pathology with activity and functional disorders in spondyloarthritis are presented.

   The article reports the problems of rheumatic disease as paraneoplastic syndrome. It includes the description of the clinical case of axial spondyloarthritis as paraneoplastic syndrome related to the neuroendocrine tumor of the duodenum. In this case, axial spondyloarthritis was characterized by rapid involvement of peripheral and axial symptoms, high acute phase reactants, resistance to drug therapy and reduction of clinical and laboratory symptoms after treatment for neuroendocrine tumor. In differential diagnostics of and paraneoplastic rheumatic disease, it is necessary to pay attention for the time of occurrence of rheumatic symptoms, clinical symptoms before and after surgical and non-surgical treatment for cancer, response to drug therapy, family cancer anamnesis, exposure to carcinogens, previous immunosuppressive therapy, as well as severity of general constitutional symptoms, atypical manifestations of rheumatic disease, age of disease debut over 50 years.

   Multiple myeloma (MM) has a large number of nonspecific clinical manifestations, which also include manifestations from the bone system. MM is more common mainly in people over 50 years of age. In this age period, patients often seek medical help due to the development of degenerative-dystrophic changes in the musculoskeletal system (osteochondrosis), which can mask early clinical stigmata of MM. The prognosis for MM depends on the stage of the process at the time of diagnosis. Patients with stage I can live for many years without any treatment, while patients with stage III renal complications do not live long. Currently, advances in pharmacotherapy can improve patient survival. In this regard, the issue of early diagnosis of this condition comes to the fore. The proposed clinical observation considers the interpretation of individual clinical signs that allow MM to be suspected in patients with degenerative-dystrophic spinal disease. Thus, the clinical case we observed is interesting not only from the point of view of the importance of the clinical diagnosis, but also the timeliness of the start of treatment, which largely determines the prognosis of the disease.

   Imbalance in the production of pro- and anti-inflammatory cytokines plays an important role in the pathogenesis of rheumatoid arthritis (RA).

  The aim of the study. To determine the concentration and frequency of increase in serum of pro- and anti-inflammatory cytokines in patients with RA in the advanced stage of the disease, assessment of the relationship between them, clinical and laboratory activity of the disease and autoantibodies.

   Materials and methods. We examined 154 RA patients (41 men and 113) women, of average age (56.0 [50.0; 64.0] years), disease duration (9.4 [3.0; 13.0] years), seropositive 129 (83.8 %) for IgM rheumatoid factor (RF) and/or 106 (68.8 %) antibodies to cyclic citrullinated peptides (ACCP) with moderate to high (DAS 28-ESR – 5.40 [4.65; 6.00]) disease activity. The concentration of interleukin (IL), tumor necrosis factor α (TNF-α), interferon-γ (INF-γ), soluble CD 40 ligand (sCD 40L) in serum was determined by multiplex technology.

   Results. In RA patients, the concentration of IL-6, IL-23, IL-31, IL-33 and INF-γ was significantly higher, and TNF-α values were significantly lower than in controls. The levels of IL-1β, IL-17A, IL-17F, IL-25 and sCD 40L were not different from donors. IL-10 values were significantly higher than donors, and IL-4 values were not different from controls. In RA, the frequency of IL-33 elevation was 87.0 %, IL-6 51.6 %, IL-31 48.1 %, IL-17F 46.1 %, IL-23 42.9 % and INF-γ 39.0 %, IL-17A 29.9 %, IL-1β 26.6 %, TNF-α 23.4 %, IL-25 11.7 % and sCD 40L 3.2 % of patients. IL-33 hyperproduction was significantly predominant over other cytokines (p < 0.001). Elevated values of IL-10 were found in 16.2 % and IL-4 in 12.3 % of patients. Hyperproduction of proinflammatory cytokines, except IL-25 and sCD 40L, significantly prevailed over IL-4 and IL-10. Correlations of proinflammatory cytokines among themselves and with IL-4 and IL-10 were found. High values of IL-33 were associated only with IL-31. IL-4 and IL-10 concentrations were significantly correlated with each other. IL-6 concentration was found to be associated with DAS 28-ESR, CDAI and SDAI; IL-25 and sCD 40L were associated with CDAI and SDAI; IL-17A and IL-33 were associated with SDAI; IL-4 and IL-10, with CDAI and SDAI; IL-31 and IL-33, with CRP; TNF-α and INF-γ, with CRP; IL-17A, and IgM RF and ACCP; IL-31 and INF-γ, with IgM RF. IL-4 and IL10 were positively correlated with IgM RF, and IL-4 was negatively correlated with ADCP.

   Conclusions. In RA patients in the advanced stage of the disease, there is an imbalance between pro- and anti-inflammatory cytokines, with a predominance of IL-33 production. Despite the presence of interrelationships between cytokines, there are significant differences between them in associations with clinical indices, laboratory indicators of disease activity and autoantibodies.