Background Coexisting associated diseases modify the features of rheumatoid arthritis (RA) by presenting atypical clinical manifestations and vice versa (1). The atypical signs and symptoms may lead to incorrect diagnosis or late recognition of the complications or of the associated diseases.
Objectives The aim of this study was to determine the influence of tuberculosis (Tb) or specifically of miliary disseminated tuberculosis (mTb) on the prevalence and mortality of systemic autoimmune vasculitis (SV) in RA.
Methods A randomized autopsy population of 234 in-patients with RA was studied.
RA was diagnosed clinically according to the ARA criteria.
SV, and Tb or mTb were histologically diagnosed post mortem. A relationship between SV, and associated Tb or mTb was determined by c²-tests.
Results Post-primary fibrous, or fibrocaseous Tb accompanied RA in 27 (11.5%) of 234 patients. Twelve of 27 post-primary Tb cases were histologically fibrocaseous, and 15 of 27 revealed only fibrous tuberculotic scars. In 8 of 27 patients tuberculosis was accompanied by active (miliary) dissemination, in 19 patients it was not.
SV complicated RA in 51 (21.8%) of 234 patients. Three types of vasculitis were observed: non-specific, fibrinoid necrotic, and granulomatous. Non-specific vasculitis was present in all of 51 patients, fibrinoid necrotic vasculitis in 20 of 51, and granulomatous vasculitis in 12 of 51 RA patients with SV. SV led to death in 23 (9.8%) of 51 patients
The statistical links between prevalence and mortality of SV (with or without granulomatous character), and coexistent Tb or mTb accompanying RA are summarized in Table. Fibrinoid necrotic vasculitis not correlated with Tb or mTb; not indicated in Table (*means negative value of association’s coefficient).
Conclusions The significant and positive correlation between Tb (especially of its fibrocaseous form) or mTb, and vasculitis means a positive influence of Tb on prevalence of vasculitis in RA. Miliary dissemination of Tb promote the lethal outcome of vasculitis as a complication.
The close relationship between granulomatous vasculitis and Tb is due to the disease modifying effect of Tb or mTb (1).
Tb is one of the most important associated diseases accompanying RA. In our autopsy population only one case of Tb with mTb and a lethal outcome was clinically recognized. The steroid, immunosuppressive or anti- TNF-alpha treatment of RA markedly increases the risk of activation of inactive fibrous or fibrocaseous tuberculosis.
The granulomatous type of systemic vasculitis is an important diagnostic histologic feature of disseminated miliary tuberculosis in RA patients. Tb or mTb (endogenous exacerbation of post-primary tuberculosis) must be excluded clinically in case of histologically detected granulomatous type of vasculitis
Apáthy Á, Bély M: Co-morbidity in Rheumatoid Arthritis: Influence of Associated Diseases on the Prevalence of Co-existent Complications of RA. Ann Rheum Dis 2009; 68(Suppl. 3): 407-408
Disclosure of Interest None Declared