Association between tumor necrosis factor inhibitor (TNFi) therapy and changes in C-reactive protein (CRP), blood pressure, and alanine aminotransferase (ALT) among patients with psoriasis, psoriatic arthritis, or rheumatoid arthritis
To the Editor: The use of tumor necrosis factor inhibitors (TNFi) for psoriasis was associated with a significant reduction in myocardial infarction incidence and risk,1 and in cardiovascular mortality.2,3 The objective was to assess changes in C-reactive protein (CRP), systolic blood pressure (SBP), diastolic blood pressure (DBP), and alanine aminotransferase (ALT) for patients with psoriasis, psoriatic arthritis, or rheumatoid arthritis exposed to a TNFi with concomitant exposure to methotrexate (MTX) compared with patients exposed to MTX therapy with no TNFi.
The full study methods are listed in the primary article,4 and a secondary article has some additional details.5 The study protocol was approved by the local institutional review board. This was a retrospective cohort study from data extracted from the electronic databases of the Kaiser Permanente Southern California (KPSC) Health Plan. This retrospective cohort study was conducted using data from KPSC from January 1, 2002, to July 31, 2011. KPSC members with at least 3 International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes of psoriasis (696.1), psoriatic arthritis (696.0), or rheumatoid arthritis (714, 714.0, 714.1, 714.2, 714.4, 714.81) during the study period but before the index date were included. Patients with psoriasis, psoriatic arthritis, or rheumatoid arthritis who were exposed to MTX with and without a concomitant TNFi were the study populations.