Personal experience in the treatment of seropositive rheumatoid arthritis with drugs used in combination

Tuberculosis infection in patients with rheumatoid arthritis and the effect of infliximab therapy

OBJECTIVE

According to the Centers for Disease Control and Prevention, the 1999 and 2000 incidence rates for tuberculosis (TB) in the US population were 6.4 and 5.8, respectively, per 100,000 persons. Recently, reports of TB following infliximab administration have raised questions regarding the rate of TB in patients with rheumatoid arthritis (RA) generally and in those treated with infliximab in clinical practice. We undertook this study to determine the baseline rate of TB in RA prior to the introduction of infliximab and to determine the rate of TB among those currently receiving infliximab.

METHODS

We surveyed patients with questionnaires, followed by detailed validation from medical records and physician reports. In study 1, we evaluated 10,782 RA patients in 1998-1999 prior to the widespread use of infliximab. In study 2, we evaluated 6,460 infliximab-treated patients in 2000-2002.

RESULTS

In study 1, the lifetime rate of TB was 696 per 100,000 patients (95% confidence interval [95% CI] 547-872). Of these cases, 76.8% occurred prior to the onset of RA. During the period of prospective followup, 1 case of TB developed during 16,173 patient-years of followup, yielding a rate of 6.2 cases (95% CI 1.6-34.4) per 100,000 patients. In study 2, the TB incidence rate among infliximab-treated patients was 52.5 cases (95% CI 14.3-134.4) per 100,000 patient-years of exposure. Three of the 4 cases occurred in patients with a history of TB exposure, and no cases occurred in persons with recent TB skin tests or prophylaxis.

CONCLUSION

The rate of TB is not increased in RA patients generally. Among infliximab-treated patients, the rate is 52.5 cases (95% CI 14.3-134.4) per 100,000 patient-years of exposure. A thorough medical history regarding TB, as well as tuberculin testing and radiographic examination (if indicated), should be an essential component of anti-tumor necrosis factor therapy.

Combination treatment of severe rheumatoid arthritis with cyclosporine and methotrexate for forty-eight weeks: an open-label extension study. The Methotrexate-Cyclosporine Combination Study Group

OBJECTIVE

To determine whether the clinical benefit and favorable safety profile previously noted with the combination of cyclosporine (CSA) and methotrexate (MTX) given for 24 weeks in patients with rheumatoid arthritis (RA) would be maintained for a further 24 weeks, and whether the addition of CSA in patients who had previously been randomized to receive placebo + MTX would result in clinical benefit.

METHODS

Eligible subjects from the initial study (weeks 0-24), in which the addition of placebo or CSA to MTX therapy was compared in patients with RA that was partially responsive to MTX, were enrolled. Patients who had received CSA + MTX continued this regimen for a further 24 weeks (weeks 24-48) (group 1; n = 48), and patients who had initially received placebo + MTX now received CSA + MTX for 24 weeks (weeks 24-48) (group 2; n = 44), in an open-label extension study. The primary outcome measures were the number of tender joints, number of swollen joints, physician and patient global assessments, pain, functional disability as measured by the modified Health Assessment Questionnaire, and erythrocyte sedimentation rate.

RESULTS

Of the 92 patients enrolled, 80 (87%) completed the extension study. In patients in group 1, the clinically and statistically significant improvement in response outcomes previously noted at week 24, ranging from 25% to 50%, was maintained through week 48. In patients in group 2, the addition of CSA resulted in significant clinical improvement. By week 48, most outcome measures in group 2 patients were similar to those in group 1 patients. CSA treatment resulted in a small increase in serum creatinine levels, but only 1 patient was withdrawn from the study for this reason.

CONCLUSION

The clinical improvement previously observed in patients treated with the CSA + MTX combination for 24 weeks was maintained for 24 subsequent weeks, without serious adverse effects, and was also observed in the patients whose treatment was switched from placebo + MTX to CSA + MTX.

Acute febrile toxic reaction in patients with refractory rheumatoid arthritis who are receiving combined therapy with methotrexate and azathioprine

OBJECTIVE

To assess the frequency and clinical features of an acute febrile toxic reaction (AFTR) in patients with refractory rheumatoid arthritis (RA) receiving combined therapy with methotrexate (MTX) and azathioprine (AZA).

METHODS

A cohort of 43 RA patients being treated with MTX/AZA combination therapy were studied. In all of them, RA had been refractory to single-therapy disease-modifying antirheumatic drugs. We analyzed the frequency and clinical features of AFTR, which consisted mainly of the development of fever, leukocytosis, and cutaneous leukocytoclastic vasculitis when AZA was added to the MTX regimen.

RESULTS

Four of the 43 patients (9.3%) who had been receiving long-term, well-tolerated treatment with MTX (mean +/- SD 375.5 +/- 159.5 days, range 227-561 days) developed AFTR shortly (mean +/- SD 25.7 +/- 13.6 days, range 17-46 days) after the addition of AZA to the regimen. The AFTR resolved rapidly (3 +/- 1.4 days) after discontinuation of AZA and MTX. In 2 cases, rechallenge with AZA and MTX was linked to a new flare of AFTR.

CONCLUSION

The knowledge of this side effect is particularly important because it mimics a severe infectious complication related to immunosuppressive therapy, and because rechallenge can produce severe toxicity. Most of the new combined therapies for RA do not seem to be more toxic than single-drug treatment. Nevertheless, clinicians should be aware of a possible increase in side effects due to drug interactions or some other unidentified mechanism.