# Clinical characteristics and risk factors of severe myelosuppression in rheumatoid arthritis patients with csDMARD non-adherence: a case series

## TL;DR

This study shows that not following prescribed medication, especially increasing methotrexate doses, can cause severe bone marrow suppression in rheumatoid arthritis patients.

## Contribution

The study identifies medication non-adherence, particularly methotrexate dose escalation, as a novel and critical risk factor for severe myelosuppression in RA patients.

## Key findings

- Medication non-adherence was found in 50% of cases, with unauthorized methotrexate dose escalation being the main pattern.
- All patients developed severe Grade III to IV bone marrow suppression, with 66.7% experiencing pancytopenia.
- Common complications included febrile neutropenia, oral mucositis, and gastrointestinal bleeding.

## Abstract

This study investigated the clinical characteristics and risk factors of bone marrow suppression in rheumatoid arthritis (RA) patients treated with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs) to provide evidence for improving medication safety. We retrospectively analyzed clinical data from 30 RA inpatients with csDMARDs-induced bone marrow suppression hospitalized at the Affiliated Hospital of Zunyi Medical University between August 2022 and January 2025. Methotrexate was part of the treatment regimen for twenty-seven patients, accounting for 90% of the cohort. Medication non-adherence was identified in fifteen patients, representing 50% of cases, with unauthorized dose escalation being the primary pattern. All patients developed severe Grade III to IV bone marrow suppression. Pancytopenia was observed in twenty patients, constituting 66.7% of the total. Common complications included febrile neutropenia, oral mucositis, and gastrointestinal bleeding. Following comprehensive treatment, all patients achieved hematologic recovery and were discharged. Our findings indicate that medication non-adherence, particularly self-driven escalation of methotrexate dosage, is a critical risk factor for life-threatening bone marrow suppression in rheumatoid arthritis patients. These results underscore the necessity of enhanced patient education, strict adherence monitoring, and rigorous hematologic surveillance for high-risk individuals.