Background The risk of tuberculosis is higher in rheumatoid arthritis (RA) or other autoimmune diseases than in a normal population.
Objectives The aim of this study was to determine the mortality due to tuberculosis (Tb) or miliary disseminated tuberculosis (mTb) in RA, and the incidence of clinically missed diagnosis of Tb or mTb in RA.
Methods A randomized autopsy population of 234 in-patients with RA was studied.
RA was diagnosed clinically according to the ARA criteria.
The post-primary tuberculosis, the miliary dissemination and mortality of tuberculosis were histologically diagnosed post mortem. The cases with clinically missed diagnosis of Tb or mTb were analysed retrospectively by reviewing the clinical and pathological reports, tissue samples and the histological slides.
Results Post-primary fibrous, or fibrocaseous tuberculosis accompanied RA in 27 (11.5%) of 234 cases. Post-primary tuberculosis was localized to the lungs. Twelve of 27 post-primary Tb cases were histologically fibrocaseous, and 15 of 27 revealed only fibrous tuberculotic scars. In 8 of 27 patients (3.41% of 234, and 29.63% of 27), tuberculosis was accompanied by active (miliary) dissemination (29.62% of 27, and 3.42% of 234 patients). All 8 patients were females.
Tuberculosis led to death in 3 cases (1.28% of 234, 1.11% of 27, and 37.5% of 8). Two patients died of circulatory failure due to Tb complicated by miliary dissemination and one died by massive internal bleeding due to propagation of fibrocaseous cavernosus tuberculotic foci and erosion of a small branch of a pulmonary artery (11.11% of 27, and 1.28% of 234 patients).
Tuberculosis was clinically recognized only in this latter of three lethal cases (3.7% of 27); in 26 patients (with or without miliary dissemination, and with or without lethal outcome) tuberculosis were clinically missed (96.3% of 27).
Conclusions In our autopsy population three of 234 RA patients died of tuberculosis and miliary dissemination. However, only one of 27 post-primary tuberculosis cases was clinically detected.
Coexisting complications modify the basic disease (RA) and present atypical clinical manifestations (1). The atypical symptoms may lead to incorrect diagnosis or late recognition of the complications or associated diseases. The age of the patients, the autoimmune character of the underlying disease, the steroid and/or immunosuppressive treatment may also play a role in missing the diagnosis of miliary tuberculosis.
Excluding Tb in autoimmune disease may be difficult. Recognizing the diagnostic clinical-laboratory parameters (2) and/or knowledge of any histological evidence of existing Tb is crucial in the patients’ history. The histological diagnosis of Tb is straight forward in most cases, but rheumatoid nodules in the lungs may cause differential diagnostic problems.
Apáthy Ágnes, Bély M: Co-morbidity in Rheumatoid Arthritis: Influence of Associated Diseases on the Prevalence of Co-existent Complications of RA - A Retrospective Clinicopathologic Statistical Study of 234 Autopsy Patients. Ann Rheum Dis 2009; 68(Suppl. 3): 407-408 www.abstracts2view.com/eular/
Apáthy Ágnes, Bély M: Miliary Dissemination of Tuberculosis in Rheumatoid Arthritis - Clinical-laboratory parameters, demographics and duration of disease associated with miliary tuberculosis. A retrospective clinicopathologic study of 161 autopsy patients. Ann Rheum Dis 2004; 63(Suppl 1): 167
Disclosure of Interest None Declared