L. Tsyhanyk, O. Abrahamovych, U. Abrahamovych, O. Romanyuk, S. Guta

Danylo Halytsky Lviv National Medical University

Introduction. Systemic Lupus Erythematosus (SLE) is an autoimmune systemic disease, which is characterized by multiple organ disorders, in particular – bones. The development of osteoporosis (OP) is an extended process and even the complicated aggravation does not have enough «instant» effect, which could be marked on the bone state and could have been tested via densitometry. Therefore, there is a necessity for research of much more important indicators. It became at once a peculiar marker of SLE activity and OP necessity.

Aim. To analyze the interconnections between bone remodeling markers and Systemic Lupus Erythematosus activity index.

Matherials and methods. In the randomized way, with the preliminary stratification by female gender and premenopausal status presence 123 patients, diagnosed with SLE according to American Rheumatologist Union (1997) (experimental group (EG)) were included into the study and were provided with the complex clinically laboratory and instrumental examination of all organs and systems. The age of the patients of EG was from 21 to 51 years (the average age on the examination moment – 41.13 ± 12.04 years); the average illness duration was 10.08 ± 0.72 years; 100.0 % of the patients took methylprednisolone in a dose (in recalculation on prednisolone) from 5.0 to 30.0 mg/day (the average dose – 8.99 ± 0.65 mg/day, the average course dose – 224.69 ± 97.6 g) and calcium supplements in a daily dose of 1000.0 mg in a combination with vitamin D in a daily dose 400.00 MO. There were 25 particularly healthy premenopausal women of the appropriate age in the control group (CG).

It was used SLEAI of C. Bombardier et al. (1992) to measure the activity of the disease. In both groups we have investigated the levels of osteocalcin, P1NP and beta-crossLaps to measure the remodeling speed.

Results. The average osteocalcin content in patients of both groups was significantly lower in comparison with healthy ones – 13.42 ± 5.43 ng/ml (p < 0.001) and 18.3 ± 0.37 ng/ml accordingly. Regarding the average P-crossLaps level, a significant difference between both examined groups was noticed. Higher level of it was found in SLE patients – 0.40 ± 0.25 ng/ml, and 0.26 ± 0.08 ng/ml (p < 0.05) in healthy individuals.

Because of the percentile analysis, we have discovered that there was osteocalcin level in a range 7.51-22.73 ng/ml, median – 12.39 ng/ml in EG people and 15.22-27.76 ng/ml, median – 17.70 ng/ml in healthy women. P1NP level was in a range 10.34-84.20 ng/ml, median – 32.82 ng/ml in SLE people and 19.53-58.34 ng/ml, median – 41.20 ng/ml in healthy women. Beta-crossLaps content was in a range 0.11-1.01 ng/ml (P5-P95), median – 0.34 ng/ml, and 0.15-0.42 ng/ml (P5-P95), median – 0.23 ng/ml in controls.

Increase of total activity indicator, according to SLEAI, negatively influences the bone tissue formation marker, – SLEAI activity increase by 1 point causes osteocalcin content decrease in blood serum by 0.19 ng/ml.

SLE activity increase, according to SLEAI, by 1 point causes P-crossLaps level in blood serum increase by 0.010 ng/ml, that is why we confirm that the increase of illness activity can cause bone fracture.

The correlation between the bone remodeling markers and some parameters of SLEAI was discovered. The patients with psychosis manifestations were observed to have the disorders of the osteoblastic function because of the osteocalcin level decrease in blood serum; with alopecia – P1NP, with organic brain syndromes (myositis, thrombocytopenia, proteinuria) – osteocalcin and P1NP). Leukopenia, proteinuria, high anti-dsDNA, osteoclastic function disorders are associated with beta-crossLaps level increase in blood serum. We have also discovered the correlation between the bone remodeling markers and constellation of the indices, which have the highest coefficient of association with bone metabolism markers (combination of psychosis, organic brain syndromes, headache, thrombocytopenia, leukopenia with osteocalcin; headache, proteinuria, mucous membranes ulcerations with beta-crossLaps), which let us highlight the risk groups on the presence of bone remodeling disorders and to determine the correct examination tactics and treatment of SLE accordingly.

Conclusions. Researching the interconnections between bone remodeling markers and SLEAI by C. Bombardier et al. (1992), we can state that the average osteocalcin content in blood serum was much lower in experimental group and beta-crossLaps was higher in comparison with the healthy group. It shows us that bone resorption predominates over the bone formation processes in SLE patients. Increasing of total activity indicator, according to SLEAI, negatively influences the bone tissue formation marker, – SLEAI activity increase by 1 point causes osteocalcin content decrease in blood serum by 0.19 ng/ml.

SLE activity increase according to SLEAI by 1 point causes P-crossLaps level in blood serum increase by 0.010 ng/ml, that is why we confirm that the increase of illness activity can cause bone fracture. There is a correlation between bone remodeling markers with particular Systemic Lupus Erythematosus activity index and indicators constellation, which have the highest associated coefficient with bone metabolism markers. There are the correlations between the combination of psychosis, organic brain syndromes, headache, thrombocytopenia, leukopenia with osteocalcin; headache, proteinuria, mucous membranes ulcer with P-crossLaps, which let us highlight the risk groups on the presence of bone remodeling disorders and to determine the correct examination tactics and treatment of SLE accordingly.

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