FRI0055 PREVALENCE OF CLINICALLY LATENT TUBERCULOSIS IN RHEUMATOID ARTHRITIS – A RETROSPECTIVE CLINICOPATHOLOGIC STUDY OF 161 AUTOPSY PATIENTS
Authors: M. Bély, Á. Apáthy
Journal: Annals of the Rheumatic Diseases (2020)

Background: The risk of tuberculosis ( TB ) is higher in rheumatoid arthritis ( RA ) than in the general population. Objectives: The aim of this study was to determine the prevalence and histological characteristics of post-primary inactive or active TB in RA , to appraise the involvement of different organs, and to statistically assess the relationship between inactive and active TB in RA . Methods: At the National Institute of Rheumatology 9475 patients died between 1969 and 1992; among them 161 with RA and all of them were autopsied. RA was confirmed clinically according to the criteria of the ARA . TB was detected at autopsy and specified histologically, retrospectively reviewing all available clinical and pathological reports. Demographics of different patient cohorts were compared with the Student t-probe. The relationship between inactive TB and active TB with miliary dissemination was analyzed with χ 2 -test. Results: Post-primary TB was associated with RA in 21 ( 13.04% ) of 161 patients. Post-primary TB was localized to the lung. Twelve (57.14%) of 21 TB were histologically only fibrous, pigmented (antracothic) tuberculotic scars ( fTB ), and 9 (42.86%) of 21 revealed a fibrocaseous tubercle ( fcTB ). One of 12 fTB and 5 of 9 fcTB were associated with disseminated (miliary) tuberculosis ( mTB ) in 6 (3.7% of 161; 28.57% of 21) RA patients with fTB or fcTB . Demographics, onset and duration of disease of 161 RA patients with TB , fTB , fcTB , or mTB are summarized in Table. Sex Number of autopsies Mean age in years at death ±SD Range of age (in years) Mean age at onset of disease ± SD Disease duration (in years) ±SD RA patients (total) 161 65.32±12.95 16–88 50.83±16.96 14.43±10.51 without TB 140 of 161 64.77±13.28 16–88 50.22±16.99 14.36±10.13 with TB 21 of 161 69.00±9.70 50–84 54.19±16.39 14.81±12.41 with fibrous TB 12 of 21 70.92±8.48 59–84 52.33±16.01 18.58±12.76 with fibrocaseous TB 9 of 21 66.44±10.59 50–80 56.67±16.55 9.78±9.91 with miliary TB 6 of 21 68.33±11.09 50–82 58.67±8.24 9.67±4.85 The mean age of RA patients was higher with TB , fTB , fcTB or mTB in comparison to total population or to the patients without TB , but the difference was only significant between patient cohorts with fTB and RA patients without TB (70.92 years versus 64.77, p &lt;0.043 ). There was a definitely shorter duration of RA in patients with fcTB or mTB compared to the total population . Proliferative or exudative epithelioid granulomatous mTB involved different organs, such as lung in 5, liver in 3, spleen in 2, lymph nodes in 2, adrenal gland in 1, synovial membrane in 1, vertebrae in 1 and pituitary gland in 1of 6 RA patients with active mTB . There was a significant correlation between: TB and mTB (c=1, χ 2 =33.96, p&lt;0.00000001), TB and fTB (c=1, χ 2 =78.36, p&lt;0.00000001), TB and fcTB (c=1, χ 2 =55.69, p&lt;0.00000001), or fcTB and mTB (c=0.99, χ 2 =56.89, p&lt;0.000001). The link between fTB and mTB was not significant (c=0.45, χ 2 =0.007, p&lt;0.9333 – NS). Conclusion: TB, fTB, fcTB, or mTB complicated RA in both sexes, and a t any time in the course of the disease. The mean age at death was higher in all forms of TB . Significant difference was only in mean age of fTB compared to the patients’ cohort without TB . Fibrocaseous tubercle or miliary dissemination of tuberculosis reduced definitely the survival time (and disease duration) of aged RA patients. Post-primary TB especially fcTB (mostly in the lungs) represents a high risk of miliary dissemination in RA . In our autopsy material mTB was the consequence of endogenous exacerbation of TB (and was not due to an exogenous reinfection), based on the high values of Youle’s association coefficients between TB or fcTB and mTB . The mTB may be considered as a terminal phenomenon, because of the limited numbers of granulomas involving only a few organs. The exudative character – beside proliferative epithelioid granulomas – must be regarded as histological evidence of impaired immune reactivity, an unfavorable prognostic sign in elderly patients, forecasting the possible fatal outcome of RA associated TB . Disclosure of Interests: None declared