Treatment continuation in patients receiving biological agents or conventional DMARD therapy

OBJECTIVE

To compare drug continuation rates in patients with rheumatoid arthritis who start on a biological agent and in a control group of patients with a change in disease modifying antirheumatic drug (DMARD) treatment after previous DMARD failure.

METHODS

Patients with rheumatoid arthritis enrolled in the German biologics register between May 2001 and September 2003 were included in the study. Data were available for 511 patients treated with etanercept, 343 with infliximab, 70 with anakinra, and 599 controls. Propensity scores were used to select a subsample of patients from the control group who were likely to be treated with biological agents because of their disease severity, as well as comparable infliximab and etanercept cases.

RESULTS

Treatment continuation after 12 months was similar for etanercept (68.6% (95% confidence interval, 62% to 75%)) and infliximab (65.4% (58% to 73%)) but lower for anakinra (59% (41% to 77%)). Treatment continuation was more likely for patients on combinations of biological agents and DMARDs than for those on infliximab or etanercept alone. Patients treated with biological agents were more severely ill than those in the control group and had more previous DMARD failures. After adjustment for baseline differences, the continuation rates were higher in patients treated with biological agents than in comparable control patients treated with leflunomide or leflunomide/methotrexate.

CONCLUSIONS

Treatment continuation of biological agents in clinical practice is less likely than in randomised clinical trials but more likely than in comparable controls treated with conventional DMARDs.

Coexistence of antitopoisomerase I and anticentromere antibodies in patients with systemic sclerosis

BACKGROUND

Antibodies targeting DNA topoisomerase I (ATA) or centromere proteins (ACA) are associated with clinical subsets of patients with systemic sclerosis (SSc). The occurrence of those autoantibodies is considered to be mutually exclusive.

OBJECTIVE

To describe the clinical and immunogenetic data of three patients who are co-expressing both antibodies, and then review previous publications.

METHODS

Both antibodies were detected by different methods, including indirect immunofluorescence technique, enzyme linked immunosorbent assay, immunodiffusion, and immunoblot. Patients were HLA typed by serological and molecular genetic methods. Data were extracted from published reports for comparison. The search for published studies was through Medline and other database research programmes.

RESULTS

During routine laboratory diagnostics over several years three patients with scleroderma and coincidence of ATA and ACA were identified: patient 1 with diffuse SSc, Raynaud's phenomenon, puffy fingers and fingertip necrosis, contractures, and calcinosis; patient 2 with diffuse SSc, Raynaud's phenomenon, oedema of the hands, and interstitial calcinosis of hands, knees, and shoulders, and pulmonary fibrosis; patient 3 with scleroderma of hands, forearms, and face, Raynaud's phenomenon, puffy fingers, finger contractures, fingertip necrosis, and calcinosis. All three patients studied were carriers of HLA alleles known to be associated with these autoantibodies. In serial measurements the concentrations of the two antibodies showed independent or even reverse fluctuations. Screening of 100 patients with ACA for ATA and vice versa disclosed no further patients with coincidence of these antibodies. Twenty eight cases of ACA/ATA coexistence in 5423 patients (0.52%) with SSc or SSc associated symptoms were found in an analysis of published studies.

CONCLUSION

The expression of ATA and ACA is not totally mutually exclusive, but coincidence is rare (<1% of patients with SSc). Patients with both autoantibodies often have diffuse scleroderma and show immunogenetic features of both antibody defined subsets of SSc.