TOPLINE:

Among patients with autoimmune inflammatory rheumatic diseases (AIRDs) who received high-dose glucocorticoids (GCs) for ≥ 4 weeks, a scoring system to identify patients at high risk for serious infections demonstrated favorable performance, with patients in the high-risk group showing a greater risk for serious infections than those in the low-risk group.

METHODOLOGY:

• Researchers included patients with AIRDs from two tertiary referral hospitals in South Korea who received prolonged high-dose GCs (≥ 30 mg/d prednisone equivalent) for ≥ 4 consecutive weeks between January 2004 and December 2019 to identify risk factors for serious infection and develop a prediction model.
• They included 1635 patients with AIRDs (mean age, 46.1 years; 67.7% female) in the derivation cohort for model development and 672 patients (mean age, 50.8 years; 62.5% female) in the validation cohort, with review by a rheumatologist to adjudicate AIRD diagnoses (such as systemic lupus erythematosus and idiopathic inflammatory myopathy) and confirm high‑dose GC exposure.
• The primary outcome was the 1-year incidence of serious infections, defined as infections requiring hospitalization and/or intravenous antimicrobial therapy. The secondary outcomes were incident infections by pathogen type (bacterial, fungal, and viral), infection-related death, and all-cause death.
• Investigators applied Cox regression with least absolute shrinkage and selection operator (LASSO) regularization to select covariates from 19 prespecified candidate predictors for the final model. The discrimination performance was assessed using Harrell’s C-index and the area under the curve of time-dependent receiver operating characteristic curve (AUROC) at 1 year.
• A scoring system, the CORAL score, was developed, with each letter representing specific covariates: C for cyclophosphamide; O for older age; R for decreased renal function and rituximab use; A for low albumin levels, antineutrophil cytoplasmic antibody-associated vasculitis (AAV), and anemia; and L for interstitial lung disease. The score ranged from 0 to 20, with patients stratified into low-risk (score ≤ 6) and high-risk (score > 6) groups.

TAKEAWAY:

• The incidence of serious infections was 10.5 per 100 person‑years (95% CI, 9.0-12.3) in the derivation cohort and 10.1 per 100 person‑years (95% CI, 7.9-12.9) in the validation cohort. The 1-year incidence of serious infections was 6.05 (95% CI, 4.73-7.62) in the low-risk group compared with 30.66 (95% CI, 24.35-38.10) in the high-risk group, with a higher risk for serious infections in the high-risk group (hazard ratio [HR], 4.85; 95% CI, 3.53-6.67).
• The rates of infection-related mortality (HR, 10.88; 95% CI, 4.79-24.71) and all-cause mortality (HR, 4.54; 95% CI, 2.91-7.11) were substantially higher in the high-risk group than in the low-risk group.
• Eight predictors selected through the LASSO process were age ≥ 60 years, interstitial lung disease, AAV, decreased renal function, anemia, low serum albumin levels, cyclophosphamide use, and rituximab use. The AUROC for the final model was 0.726 (95% CI, 0.681-0.771) in the derivation cohort and 0.763 (95% CI, 0.700-0.826) in the external validation cohort.
• In the validation cohort, patients in the high-risk group had a significantly greater risk for serious infections than those in the low-risk group (HR, 3.15; 95% CI, 1.89-5.26).

IN PRACTICE:

“[The] result demonstrates the clinical applicability of our scoring system, indicating that intensive monitoring and preventive strategies should be considered for patients identified as high risk. Furthermore, the CORAL score demonstrated comparable performance in the independent validation cohort, thereby minimizing the risk of overfitting,” the authors wrote.

SOURCE:

The study was led by Se Rim Choi, MD, Hanyang University Hospital for Rheumatic Diseases in Seoul, South Korea. It was published online on March 5, 2026, in Arthritis Research & Therapy.

LIMITATIONS:

Both the derivation and validation cohorts consisted exclusively of patients from South Korea, which may affect the generalizability. The retrospective study design may have introduced potential bias from unmeasured confounding factors, including unavailable data on body weight and vaccination status. Information regarding hospitalizations or intravenous antimicrobial administration at external hospitals may not have been captured in the database, potentially leading to underestimation of serious infection incidence.

DISCLOSURES:

The research was supported by a grant from the National Research Foundation of Korea. The authors declared having no competing interests.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.