Objective:

To determine the correlation between hematologic ratios and alopecia areata (AA) severity.

Approach:

• Study Design: A nationwide, retrospective cohort study analyzing data from 147,020 AA patients and 141,598 matched controls.
• Data Analysis: Investigators examined neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), eosinophil-to-lymphocyte ratio (ELR), eosinophil-to-neutrophil ratio (ENR), and eosinophil-to-monocyte ratio (EMR) as potential biomarkers.
• Patient Selection: Included adult AA patients diagnosed between 2005 and 2020 with complete blood count data; excluded those with recent infections, malignancies, or surgeries.

Key Findings:

• Higher NLR (odds ratio [OR] = 1.02, 95% confidence interval [CI] = 1.01–1.03, P < .001) and ELR (OR = 1.21, 95% CI = 1.05–1.39, P = .007) values were observed in AA patients compared to controls.
• Moderate-severe AA patients had significantly higher NLR (OR = 1.11, 95% CI = 1.09–1.1, P < .001), PLR (OR = 1.09, 95% CI = 1.05–1.13, P < .001), ELR (OR = 2.06, 95% CI = 1.67–2.53, P < .001), and EMR (OR = 1.07, 95% CI = 1.03–1.07, P < .001) compared to mild cases.
• Cut-off values for severe AA were identified for NLR (1.87), PLR (126.36), ELR (0.09), EMR (0.59), and ENR (0.09), with area under the curve values ranging from 0.50 to 0.54.

Interpretation:

Limitations:

• Predictive accuracy of the biomarkers was modest.
• Further research is needed to define sensitivity and specificity, particularly with other blood markers.

Conclusion:

Sources:

• PLOS ONE Study