A retrospective record review of tuberculous infections in rheumatoid arthritis patients on biologics in Malaysia

INTRODUCTION

The aim of this study was to analyse the clinical characteristics of patients with rheumatoid arthritis receiving biologics therapy and investigate the association between types of biologics and tuberculosis (TB) infections in 13 tertiary hospitals in Malaysia.

MATERIALS AND METHODS

This was a retrospective study that included all RA patients receiving biologics therapy in 13 tertiary hospitals in Malaysia from January 2008 to December 2018.

RESULTS

We had 735 RA patients who received biologics therapy. Twenty-one of the 735 patients were diagnosed with TB infection after treatment with biologics. The calculated prevalence of TB infection in RA patients treated with biologics was 2.9% (29 per 1000 patients). Four groups of biologics were used in our patient cohort: monoclonal TNF inhibitors, etanercept, tocilizumab, and rituximab, with monoclonal TNF inhibitors being the most commonly used biologic. The median duration of biologics therapy before the diagnosis of TB was 8 months. 75% of patients had at least one co-morbidity and all patients had at least one ongoing cDMARD therapy at the time of TB diagnosis. More than half of the patients were on steroid therapy with an average prednisolone dose of 5 mg daily.

CONCLUSION

Although the study population and data were limited, this study illustrates the spectrum of TB infections in RA patients receiving biologics and potential risk factors associated with biologics therapy in Malaysia.

POS0585 INCIDENCE AND CLINICAL CHARACTERISTICS OF MALIGNANCY IN RHEUMATOID ARTHRITIS PATIENTS – DATA FROM THE MALAYSIAN NATIONAL INFLAMMATORY ARTHRITIS REGISTRY (NIAR)

Background

Patients with rheumatoid arthritis (RA) are at increased risk of developing malignancies, particularly hematologic malignancies. This predisposition for malignancy is attributed to the immune dysregulation, chronic inflammation and the long-term use of disease-modifying anti-rheumatic drugs(DMARDs).

Objectives

This study was undertaken to determine the incidence, patterns of malignancy and identify risk factors of malignancy among RA patients.

Methods

Individuals diagnosed with cancer after the onset of RA between year 2008 and 2020 from the NIAR RA registry were retrospectively examined. Standardized incidence ratios (SIR) and 95% confidence intervals of various cancers were calculated based on the expected and observed frequencies. The expected number of cases were extracted from the Malaysian National Cancer registry report. ANOVA, Chi-squared, and Student’s t test were used to analyze the risk factors for developing malignancy.

Results

Of the 3995 patients in the registry, 97 patients developed malignancies at a mean interval of 9.1 years after RA onset. The total follow-up time was 26841.9 person-years.

The mean age of patients was 59.3 (± 9.25) years, of which 89.7%(n=87) were women and 40%(n=39) were Chinese.

87.6%(n=84) had solid-organ tumours while 12.4%(n=13) had hematological malignancies.

Women showed increased risks of non-Hodgkin’s lymphoma (SIR = 13.1, 95% CI = 9.78 – 17.08), followed by lung cancer (SIR = 12.7, 95% CI = 10.01-15.77) and breast cancer (SIR = 8.8, 95% CI = 7.84 – 9.83).

Men showed increased risks of lung cancer (SIR = 3.79, 95% CI = 2.81 – 4.92) and colorectal cancer (SIR = 1.69, 95% CI = 1.09 – 2.42).

The risk factors for developing malignancy (p<0.05) include age above 60 years, long duration of RA disease, and higher disease activity states.

There were no associations between gender, ethnicity, autoantibodies and DMARDs exposure.

Conclusion

The overall malignancy incidence was increased among RA patients, with women having a 4-fold higher risk. Though the incidence of solid-organ malignancies is higher, the SIR once adjusted was highest for non-Hodgkin’s lymphoma which is consistent with literature review. Hence, cancer screening with continued vigilance among RA patients is recommended.

References

[1]Hwajeong Lee. The risk of malignancy in Korean patients with rheumatoid arthritis. Yonsei Med J. 2019;60(2):223-229.

[2]X.R. Lim, X. Gao, W.L.J. Tan, L.W. Koh, T.Y. Lian,W.Q. See, K.P. Leong, E.T. Koh

•.Abstract: Singapore Patients with Rheumatoid Arthritis Have A Higher Incidence of Solid-Organ Malignancies than The General Population: Findings from The TTSH RA Registry.

•bAnnals of the rheumatic diseases, BMJ Journals

[3]Summary of Malaysia national cancer registry report 2012-2016, Institut Kanser Negara, Ministry of Health, Malaysia

Table 1.

SIR of Malignancy among Rheumatoid Arthritis Patients by Sex and Age Groups

Sex and Age GroupNumber of Patients (%)Person-YearsIncidenceSIR (95% CI*)ObservedExpectedSex (Age Group)Males10 (10.31%)48641.5 (0.54 - 2.94)Age at Diagnosis 50-604 (10.31%)12221 (0.09 - 2.87) 60-706 (60%)36422 (0.52 - 4.44)Females87 (89.69%)54059183.28 (2.49 - 4.17)Age at Diagnosis 30-5012 (13.79%)31751.4 (0.55 - 2.63) 50-6034 (39.08%)22824102.4 (1.54 - 3.46) 60-7041 (47.13%)2812839.33 (6.2 - 13.11)

SIR, standardized incidence ratios; CI, confidence interval.Acknowledgements*CI = (√observed number of cancer cases ± 1.96 × 0.5)^2/(expected number of cancer cases).

Disclosure of Interests

None declared.