DAS28 index calculated with regard for ESR, the number of swollen/painful joints and evaluation of the patient's condition by VAS is universally used to estimate activity of rheumatoid arthritis (RA). There is a variant of calculation using C-reactive protein (CRP) instead of ESR. Our experience indicates that ESR decreases more slowly than CRP during treatment and better reflects dynamics of patients' condition. From the practical standpoint it is important to estimate activity of RA because therapeutic modalities are chosen based on the DAS28 value.
To study the influence of pharmaceutical form of methotrexate on the acute-phase response in rheumatoid arthritis.
The study included 32 patients (24 women, 8 men) aged 19-76 (mean 47.5 +/- 28.5) yr with active RA (DAS28 > 3.2) 4-30 months (11.5 +/- 7.4, median 8) in duration. Diagnosis was made using AXR criteria (1987), none of the patients previously received methotrexate injections. Inclusion criteria: initially high ESR (Westegren, mm/hr) and/or CRP (mg/l measured by a highly sensitive method). All patients were given methotrexate subcutaneously for 12 weeks as monotherapy (initial dose 10 mg, maximum one 25 mg/week). The cumulative dose was 211.36 +/- 17.2 mg.
Side effects did not require withdrawal of methotrexate. CRP level decreased faster than ERS: a 70% decrease of CRP by week 12 was recorded more frequently than that of ESR. Slow dynamics of the number of swollen joints compared with CRP may be due to the low cumulative dose of methotrexate. Duration of the disease had no effect on dynamics of acute phase characteristics.
Methotrexate injections resulted in markedly delayed development of clinical signs of improvement compared with laboratory values. CFP levels fell down much faster than ESR, Remission or low activity of RA (estimated from DAS28) occurred only in 38% of the cases after 3 month monotherapy by methotrexate injections. It is concluded that efficacy of this drug should be estimated no sooner than 4 months after the onset of the treatment.