Levels of fecal «hemoglobin/ haptoglobin» complex in patients with osteoarthritis depending on the intake of nonsteroidal anti-inflammatory drugs

Abstract

Objective — to study levels of fecal «hemoglobin/ haptoglobin» (Hb/ Hp) complex in patients with osteoarthritis (OA) and to assess the probability of its correlation with the fecal calprotectin (FCP) levels.Materials and methods. Stool specimens were collected from 36 patients with OA, aged 34 ‑ 85 years, from the hospitals and outpatient medical facilities of Kyiv and Kyiv Region. These patients were divided into two groups: the NSAID group included patients who regularly received NSAIDs, and group of patients, not treated with NSAIDs. The control group consisted of twelve healthy individuals. Immediately after collection, the stool samples were frozen up to –20°C. The Hb/ Hp levels in feces were determined by ELISA using the RIDASCREEN® Haemo‑/ Haptoglobin Complex kit (R‑Biopharm AG, Germany) and Rayto RT‑2100C reader (China). The concentration of the Hb/ Hp complex ≥ 2 mg/ g and higher were considered as a positive result.Results. The median fecal Hb/ Hp level in patients receiving NSAIDs was 0.669 mg/ g (IQR 0.65 — 7.3) and was statistically higher (p = 0.013) than in healthy subjects 0.65 mg/ r (IQR 0.65 — 0.65). In patients who did not take NSAIDs, the median level of fecal Hb/ Hp complex was also equal to the lower limit of determination — 0.65 µg/ g (IQR 0.65 — 0.65), however, due to single patients with elevated levels, the difference in the levels of Hb/ Hp complex in this group of patients did not reach statistical significance (p > 0.1) when compared to the patients of NSAIDs and control groups. Despite this fact, a trend has been revealed to the increase of the levels of investigated parameter in the groups (from healthy subjects to the ОА patients, receiving NSAIDs). The direct correlation of moderate strength has been established between the levels of the Hb/ Hp complex and period of NSAIDs’ administration (r = 0.411; p = 0.0115), between the levels of the Hb/ Hp complex and Lequesne index values (r = 0.512; p = 0.00631), and between the levels of the Hb/ Hp complex and FCP levels (r = 0.486; p = 0.000457).Conclusions. It has been established that NSAIDs administration was associated with the increased levels of fecal Hb/ Hp complex. This biomarker, together with fecal calprotectin, can be useful as a non‑invasive indicator of possible NSAID‑induced intestinal damage in patients with OA receiving NSAIDs.