Thank you for the opportunity to respond to the letter by Drs. Alarcón, Kremer, and Weinblatt. With all due respect for the 8 rheumatologists on the Subcommittee on Hepatic Toxicity and MTX of the ACR who developed the current guidelines (1), the number of rheumatologists included in our study (n = 123) is 15-fold larger, representing ∼5% of practicing rheumatologists in the US. These rheumatologists provided their views concerning standard, everyday care of patients with RA. Furthermore, the current guidelines appear to be based on 446 patients, rather than the quoted 700 (2), 383 of whom had been the subject of 11 previously published studies, 8 of which were continuations of 3 reports of the same patients. This methodology may have led to a misleading total.
I also agree that the current guidelines for MTX monitoring are the best we have, but they are also the only guidelines available. The assumptions concerning clinically significant liver disease rates and the risks associated with liver biopsies (3), as well as the arbitrary choice of testing intervals not supported by data (4), in the development of these guidelines have already been challenged. Other investigators have also suggested modification of the current guidelines, with less frequent laboratory monitoring (5, 6). Surely the authors are not suggesting monitoring blood tests every 4 weeks, which would be the literal interpretation of these guidelines.
Drs. Alarcón, Kremer, and Weinblatt also suggest that an abstract presented at the 2003 ACR meeting about the small number of liver function test abnormalities observed among 313 RA patients was presented as an ACR-endorsed statement by a commercial Web site for rheumatologists. This was a newsreel about the abstract about MTX and liver function test abnormalities. There was no indication of an ACR endorsement, and I personally had no control nor any role in the preparation of this newsreel.
Finally, it would be of interest to learn the current prevalence of liver function test abnormalities in patients seen by Drs. Alarcón, Kremer, and Weinblatt, to compare with data reported by me and my colleagues, to help the rheumatology community judge the optimal frequency of laboratory monitoring of patients treated with MTX.