Baseline laboratory test abnormalities are common in early arthritis but rarely contraindicate methotrexate: study of three cohorts (ESPOIR, VErA, and Brittany).

OBJECTIVE

To evaluate the prevalence of baseline abnormalities in standard laboratory tests in patients with early arthritis and their impact on selection of disease-modifying antirheumatic drugs according to American College of Rheumatology (ACR) recommendations and/or of nonsteroidal anti-inflammatory drugs.

METHODS

In three cohorts of patients with early arthritis (the ESPOIR, VErA, and Brittany cohorts), we evaluated the prevalence of anemia (hemoglobin <1 3 g/dL in men and 12 g/dL in women), leukopenia (<3500 per mm(3)), thrombocytopenia (<150000 per mm(3)), renal dysfunction (mild, creatinine clearance [CrCl]=60-89.9 mL/min; moderate, CrCl=30-59.9 mL/min; or severe, CrCl<30 mL/min), liver cytolysis (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]>N or>2N), and systemic inflammation (erythrocyte sedimentation rate [ESR]>20 and C-reactive protein [CRP]>6).

RESULTS

We evaluated 1393 patients (1018 women and 375 men). Anemia was present in 363/1366 (26.5%) patients, leukopenia in 18/1372 (1.3%), and thrombocytopenia in 13/1371 (0.9%). ESR elevation was seen in 50.4% of patients and CRP elevation in 62.7%. The level of AST was above normal in 4% and of ALT in 10% of patients. No patient had severe renal dysfunction, 5.6% had moderate renal dysfunction, and 42.6% had mild renal dysfunction. Among the 1094 patients who had undergone all the tests, only 18 (1.64%, 95% confidence interval, 1-2.64) had a formal contraindication to methotrexate therapy according to ACR recommendations (4 had leukopenia, 12 had high ALT levels, and 2 had high ALT and AST levels).

CONCLUSION

Patients with recent-onset arthritis often have anemia, mild or moderate renal dysfunction, and abnormal liver function. However, fewer than 2% have laboratory test abnormalities contraindicating methotrexate therapy.