Objective: to assess the time course of changes in the concentration of methotrexate (MTX) and its main metabolites in the red blood cells (RBC) and mononuclear cells (MNC) of patients with rheumatoid arthritis (RA), by taking into account individual characteristics (age, statin therapy, and smoking).Patients and methods. The investigation enrolled 33 MTX-treated patients (mean age 53.2±11.7 years) with RA, who underwent therapeutic drug monitoring to measure the RBC and MNC concentrations of free MTX and MTX polyglutamates (MTXPGs) with 2, 3, and 4 glutamate residues (MTXPG 2–4) in using tandem chromatomass spectrometry after 4, 12, and 24 weeks of therapy.Results and discussion. Following 12 weeks, the concentration of MTXPG4 in the MNC was higher in patients taking statins, while that of MTX and MTXPG2 in the RBC were significantly lower than in smokers. At 24 weeks, older patients were observed to have a higher MTX level and a lower MTXPG4 concentration in the RBC.Conclusion. After 24 weeks of therapy, the RBC concentration of MTPG4 was lower and that of MTX was higher in older patients than in others, which confirms data on a slower MTX metabolism in the elderly. The use of statins is likely to have a positive impact on the accumulation of MTXPG. There is a statistically significantly lower RBC concentration of MTXPG in at 12 weeks of therapy.

Background:7-hydroxy Methotrexate (7-hydroxy-MTX) is a phase I metabolite of MTX, which is converted by hepatic aldehyde oxidases. It is known that 7-hydroxy MTX can reduce the effectiveness of methotrexate, which is associated with increased excretion of methotrexate due to a decrease in polyglutamation and binding to enzymes [1].Objectives:To analyze the level of 7-hydroxy-MTX in peripheral blood cells in order to study the correlation of the level of this metabolite with the level of polyglutamates of methotrexate (MTXPGs).Methods:The prospective study included 65 patients aged 53±11 years, 50 women, 13 men, diagnosed with RA, according to the ACR/EULAR 2020 criteria, methotrexate (MTX) naiive. The duration of the disease was 7,5[4;24] months. All patients were administrated MTX subcutaneously at a dose of 10-15 mg/m2. The visits were carried out at weeks 0, 4, 12, 24 and 36, at all visits samples were taken for the content of MTXPGs with 1,2,3 and 4 glutamate residues and 7-hydroxy MTX separately in red blood cells mass (RBC) and mononuclear cells (MO). The mononuclear fraction was isolated by layering on verografin-ficoll. All patients received folic acid at a standard dose of 5 mg 24 hours after parenteral MTX administration. Samples were collected no earlier than 36 hours after MTX administration. All patients had normal renal function. Disease activity was assessed using the DAS28 index calculated by C-reactive protein.Results:The average concentration of 7-hydroxy MTX is shown in Table 1.Table 1.Level of 7-hydroxy MTX in erythrocytes and mononuclear cells, nmol/L, Median [25; 75 quartiles]7-hydroxy MTX level in:4 weeks12 weeks24 weeks36 weeksRBC18,5[3,1;61,5]10,2[3,6;50,8]10,3[1,7;36,8]7,2[0,1;25,3]MO0,8[0,1;15,2]4,0[0,1;42,2]3,5[0,1;8,1]0,4[0,1;8,9]The level of 7-hydroxy-MTX directly correlated with the level of MTXPGs 1-4, and summary MTXPG in both RBC and MO. Analysis of pairwise correlations according to Pearson showed that: after 4, 12 and 36 weeks, the level of 7-hydroxy-MTX did not correlate with the value of DAS28. After 24 weeks of therapy, the level of 7-hydroxy-MTX in RBC was inversely correlated with DAS28 of the disease (p=0.043).Conclusion:The preliminary results indicate a positive correlation between the level of 7-hydroxy-MTX and MTXPGs in RBC and MO. In this regard, the concentration of 7-hydroxy-MTX can be used as a prognostic marker for MTX therapy in the absence of opportunities in clinical centers to measure the entire line of MTXPGs in RBC and MO. Since the data obtained are somewhat at odds with the few literary sources, it is necessary to conduct further research on this fact.References:[1]Baggott JE, Morgan SL (2009) Methotrexate catabolism to 7-hydroxymethotrexate in rheumatoid arthritis alters drug efficacy and retention and is reduced by folic acid supplementation. Arthritis Rheum 60:2257–2261Disclosure of Interests:None declared

Гетерогенность клинико-морфологических форм и разнообразие манифестных вариантов системных васкулитов (СВ), ассоциированных с антинейтрофильными цитоплазматическими антителами (АНЦА), представляющих собой жизнеугрожающие редкие заболевания, обусловливают сложность их ранней диагностики. Артрит и/или арт-ралгии нередко встречаются при АНЦА-СВ и могут становиться манифестным проявлением, доминирующим в клинической картине заболевания, что следует учитывать, обсуждая случаи раннего артрита. В критериях ревматоидного артрита (РА) Американской коллегии ревматологов/Европейской антиревматической лиги (ACR/EULAR)

Background:Refractory rheumatoid arthritis (RRA) is a subtype of rheumatoid arthritis (RA), in which the sequential administration of optimal methotrexate doses in combination with glucocorticoids, and at least - two biologic disease-modifying antirheumatic drugs (bDMARDs) with different mechanisms of action during 18-24 months does not lead to a significant decrease in the inflammatory activity of RA.Objectives:to determine the reasons for the withdrawal of TNF-α inhibitors in patients with RRA.Methods:The retrospective study included data of 95 RRA patients (80 females, 80.8%), aged 23 to 80 years (mean age 57 years), treated with TNF-α inhibitors. Mean RA duration was 11.9±7.6 years. All patients were divided into 6 groups depending on the number of the lines of therapy received. A total of 154 cases of TNF-α were studied.Results:Infliximab (INF) was most often prescribed as the first line of therapy - 40 prescriptions. The reasons for the withdrawal of INF as the first bDMARDs were: insufficient effectiveness (IE) - 20 cases (50% of appointments), administrative reasons (AdmR) - 13 cases (32.5% of appointments), adverse reactions (AR) - 6 cases (15% of appointments), remission - 1 case (2.5% of appointments). In the 2nd line of therapy, INF was prescribed in only 3 cases, the drug was canceled in all cases due to IE. In 3 lines of therapy, INF was prescribed in 4 cases, the reasons for withdrawal in these cases were IE (50%, 2 cases) and AR (50%, 2 cases).Etanercept (ETC) was prescribed as the first line of therapy in 10 cases. The most common reason for withdrawal was IE in 5 cases (50% of appointments), AR - 4 cases (40%), AdmR - 1 case (10%). ETC was prescribed as a 2 line in 15 cases, the reasons for withdrawal then were: IE - 11 cases (73.3%), AR - 1 case (6.7%), AdmR - 3 cases (20%). ETC was prescribed as a 3-line therapy in 20 cases. The reasons for withdrawal were as follows: IE - 8 cases (40%), AR - 4 cases (20%), AdmR - 8 cases (40%). As a drug of 4 lines of therapy, ETC was prescribed 1 time and was canceled due to the development of AR. As the 5th line, ETC was appointed in 1 case and was canceled due to IE. ETC was assigned as line 6 in 1 case. The reason for the withdrawal was AR.Adalimumab (ADA) was prescribed as the first line of therapy in 19 cases, the reasons for withdrawal were: IE - 14 cases (73.7%), AR - 2 cases (10.5%), AdmR - 3 (15.8%). On line 2, ADA made 20 appointments, the reasons for withdrawal were: IE - 13 (65%), AR - 3 (15%), AdmR - 4 (20%). ADA was prescribed as line 3 in 8 cases, the reasons for withdrawal were: IE - 6 (75%), AR - 1 (12.5%), AdmR - 1 (12.5%). As a 4-line drug, ADA was prescribed in 4 cases and was canceled in all cases due to IE. On line 5, ADA was assigned 1 time and was discontinuation due to IE.Golimumab (GLM). He was appointed as the first line in 5 cases. The reasons for withdrawal were: IE - 1 case (20%), AdmR - 4 appointments (80%). As a 2-line drug, GLM was prescribed once and was canceled due to AdmR. The drug was not prescribed for the 3rd and 4th lines. As a 5-line therapy, it was prescribed once and was canceled due to IE.When assessing the frequency of drug withdrawal due to IE or AR, no significant differences were found between the lines of therapy. Discontinuation rates were also not statistically different in the study groups.Conclusion:The most common reason for the withdrawal of TNF-α in patients with RRA is IE. With an increase in the lines of TNF-α therapy, remission as a reason for withdrawal was not identified. As a result of the increase in the number of sequentially prescribed bDMARDs, the frequency of discontinuation of TNF-α in connection with IE did not decrease. A significant reason for cancellation is AdmR, to which we attributed the absence of the drug in the pharmacy network, financial reasons limiting the continuation oDisclosure of Interests:None declared

Background:Studying the dynamics of the methotrexate metabolites concentration in cells will help to predict the therapeutic effect and assess patient compliance. We suggest that studying the dynamics of changes in the concentration of methotrexate metabolites in mononuclear cells (MO) may be a more accurate method than measuring in red blood cells (RBC).Objectives:To study the dynamics of changes in the concentration of MTX and its metabolites in RBC and MO in methotrexate-naive patients with RA.Methods:33 patients (26 women, 7 men) aged 53.2 ± 11.7 years with a diagnosis of rheumatoid arthritis, according to the ACR / EULAR 2010 criteria, were included. All patients had GFR >60 ml/min. Patients were monitored after 4, 12, 24 and 36 weeks from the start of МТX. Mean Cell Volume (MCV) of RBC was measured by standard methods. Samples of RBC and MO were collected separately to determine the concentrations of MTX (basic monoglutamate form), total concentration of MTPG2, MTPG3 and MTPG4 (MTPG2-4), 7- hydroxymethotrexate (7-OH-MTX) by tandem mass spectrometry.Results:Table 1.Total concentration of MTPG2, MTPG3 and MTPG4 (MTPG2-4), nmol/lMe[25;75]MinMaxWeek 4RBC42.819.0;155.03987.7MO6.25.3;11.91.6147.2Week 12RBC48.117.1;89.00.1519.9MO10.93.9;31.00.9147.6Week 24RBC39.417.2;70.62.7191.8MO8.32.7;14.00.472.4A pairwise comparison of MTX, MTPG2-4 and 7-OH-MTX concentrations, according to the Wilcoxon method did not reveal statistically significant differences at weeks 4, 12 and 24. The concentration of the studied substances did not correlate with the value of the body mass index, taking statins, glucocorticoids, a cumulative dose of MTX, and the frequency of adverse reactions. At the week 4, of therapy, the level of MTPG4 in MO was inversely correlated with the duration of the disease (correlation coefficient - 0.58, p 0.05) The concentration of MTX and its metabolites in MO was lower in smokers (MTX 11.2 [2.6;21.9], 7-OH-MTX 2.1 [0.5; 10.4], MTPG2 0.5 [0.1;1.3]) than in non-smokers (MTX 46.5 [25.3;97.5], 7-OH-MTX 28.2 [7.1; 64.7], MTPG2 8.2 [4.1;32.9]), p = 0.02, 0.01 and 0.003, respectively. At week 24 of therapy, a negative correlation was found between age and MTPG4 level (correlation coefficient 0.51, p <0.05).Conclusion:The inadequate response to MT therapy in smokers, described in many previous studies, may be associated with a low concentration of the MTX metabolites in mononuclear cells.The level of MTPG4 in mononuclear cells increases more slowly in patients with a longer duration of the disease.Disclosure of Interests:None declared