Change of erythrocyte sedimentation rate as prognostic biomarker for Mycobacterium avium complex pulmonary disease through anti-mycobacterial treatment.

Background: It remains unclear whether erythrocyte sedimentation rate (ESR) accurately predicts prognosis during treatment and how ESR changes.

Objectives: We aimed to assess the predictive values of ESR as a prognostic factor of Mycobacterium avium complex pulmonary disease (MAC-PD) while on anti-mycobacterial treatment and its changes according to the treatment responses.

Design: This study is a retrospective cohort study.

Methods: This study included patients aged 18 years or older who initiated anti-mycobacterial treatment for MAC-PD at Seoul National University Hospital between January 1, 2009 and March 31, 2022. ESR should be measured at least twice, with a minimum interval of 3 months, during the initial 12 months from the commencement of antibiotic treatment. A mixed linear regression and Cox proportional-hazards models were used to analyze repeated ESR data and the association with patient survival.

Results: Of a total of 825 patients who initiated antibiotic treatment for MAC-PD, 369 patients were included in the analysis. Increased levels of ESR during the treatment process were associated with a higher risk of mortality (adjusted hazard ratio 1.03; 95% confidence interval, 1.02-1.03) after adjusting age, sex, comorbidities, presence of cavity, acid-fast bacilli smear positivity, and culture conversion at 12 months. During the treatment, ESR at 12 months of treatment significantly decreased compared to baseline ESR in both the culture-converted and not-converted groups, which was categorized based on whether the culture conversion was achieved within the 12 months after treatment initiation.

Conclusion: ESR predicted mortality during treatment and decreased over time, regardless of treatment outcomes. Our results underscore the importance of administering anti-mycobacterial treatment even in patients who did not achieve a microbiological cure.