We recently heard concern voiced regarding a report on the TNF-a Inhibitors and possible complications induced by using this class of medications. The report's abstract, "Autoimmune Diseases Induced by TNF-Targeted Therapies: Analysis of 233 Cases" can be found by clicking here.

We asked our Medical Board to comment and hopefully to clarify the information. Their official response follows…

Given the widespread use of these drugs and the taking into account this type of report, it is hard to become very alarmed by it.

First of all, the lupus question. SLE can present like RA early on and TNF blockers do not work in lupus. In the early days, we even tried anti-TNF treatment in a few of our lupus patients with "RA-like" presentations, and they didn't work. Thus you have to dismiss those patients with "pre-existent lupus-like features" (i.e., features of lupus before they got the TNF blocker). These patients may have had lupus all along. So therefore only 30 of the 92 "lupus" patients actually met criteria for lupus. For those patients with "lupus features" who did not meet criteria, it is hard to comment given how variable (and at times nonspecific) those features can be.

As far as the vasculitis issue is concerned, note that leukocytoclastic vasculitis was the most frequent type. Leukocytoclastic vasculitis frequently is a manifestation of drug allergy, such as allergy to ampicillin or other antibiotics. So many of the 75% who had only cutaneous vasculitis of the 113 patients called "vasculitis" could have been allergic to the TNF blocker (or other concomitantly administered drug).

As far as the interstitial lung disease is concerned, note that the overwhelming majority of the patients reported had RA (187/233), and interstitial lung disease is a well-recognized complication of this disease.

It would be helpful to know how many of the "non-RA" patients developed interstitial lung disease. There is no data to suggest that that TNF blockers help interstitial lung disease, and one cannot rule out that we are dealing with the natural progression of RA itself.

We are making these points because it is dangerous to over-interpret this report. Lupus is thought to be a rare complication of TNF therapy (we are aware of at least one case) and there is no reason to think systemic (extracutaneous) vasculitis may not be as well. The only way to examine this is to know the total number of patients taking anti-TNF agents, and then to divide the number of cases of lupus, vasculitis and interstitial lung disease coming on in the setting of anti-TNF treatment by this and come up with some real prevalence numbers, and then to compare these numbers with the frequency of these diseases in the general population. If we see an excess, we have the answer.

What we really need is a Registry of patients taking anti-TNF treatment to get this information. Such Registries have been organized in Europe and one is currently being organized in Latin America by PANLAR (the Pan American League Against Rheumatism). But physicians in the U.S. (the biggest market for these drugs) are traditionally resistant to participating in such Registries. Maybe the information we need to better judge this will come from the other Registries.

Until then, given that these drugs have already been extensively studied in longitudinal cohorts over many years and these complications have NOT been found to be a significant problem, let's be careful not to overreact.

Many people have been helped by these drugs, and if a patient is unwilling to take the probably small risk of autoimmune associated with them, they should discuss this with their doctor.

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