Article
Concentration of methotrexate polyglutamates in patients with rheumatoid arthritis having various clinical features
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Authors
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Galina Gridneva
- V.A. Nasonova Rheumatology Research Institute, Moscow
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Eugenia Aronova
- V.A. Nasonova Rheumatology Research Institute, Moscow
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Anastasia Kudryavtseva
- V.A. Nasonova Rheumatology Research Institute, Moscow
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Natalia Baymeeva
- Mental Health Centre
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Yury Muraviev
- V.A. Nasonova Rheumatology Research Institute, Moscow
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Elena Samarkina
- V.A. Nasonova Rheumatology Research Institute, Moscow
| Published: | September 14, 2021 |
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Outline
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Introduction: Age, gender, body weight, erythrocyte volume are personal features of patients with rheumatoid arthritis (RA), so, their effect on the results of the study cannot be excluded. It was proved that in order to obtain a normal therapeutic effect of methotrexate (MTX), it must the achieved level of tetraglutamate (MTXPG4) in erythrocytes be at least 22.5 nmol/L. The aim of this research is to assess the effect of individual characteristics of patients with RA on the concentration of polyglutamate methotrexate (MTXPG).
Methods: The investigation included 60 RA patients (26 men and 44 women), according to the ACR/EULAR 2010 criteria, who received MTX of at least 20 mg per week for at least 12 weeks. Patients of the older age category included 7 men over 60 years old and 24 women over 55 years old (group 1, n = 29), the remaining patients made up group 2 (n = 31). Concentration of MTXPGs significant for analysis (with 2,3 and 4 glutamate residues) were measured in red blood cells (RBC) by high performance liquid chromatography with mass spectrometric detection.
Results: In patients of group 1, the concentration of MTXPG2, MTXPG3 and MTXPG4 was 9.0 [4.0; 8.3], 16.1 [9.0; 16.6], 24.7 [20.8; 30.2] nmol/l, in group 2, respectively 7.5 [4.1; 9.0], 16.0 [9.9; 20.0], 23.8 [17.5; 29.2] nmol/l. The differences were not statistically significant. The groups did not differ: single and cumulative doses of MTX, the count and volume of RBC, in the duration of MTX treatment; in group 1, a good and moderate response to therapy was revealed in 9 (29%), in group 2, the number of responders to therapy was 19 (65%), p = 0.01. The BMI in group 1 was 29 ± 6 kg/m2, in group 2 25 ± kg/m2 (p = 0.0064). When comparing groups with different effect of therapy (according to ACR response criteria), no statistically significant differences were obtained. The average weekly dose of MTX, calculated per 1 m2 of the body surface, was higher in group 2 (12.6 ± 2.2 mg versus 11.3 ± 2 mg, p = 0.02). A correlation was found between the level of MTXPG2 and BMI (Spearman correlation coefficient 0.268) The concentration of MTXPG did not correlate with the total volume of RBC.
Conclusion: The concentration of MTXPG in groups of patients of different ages did not differ.
Disclosures: None declared
