Role of neutrophil-to-lymphocyte, neutrophil-to-eosinophil and platelet-to-lymphocyte ratios in the diagnosis of bullous pemphigoid and Pemphigus disease.

CONTEXT: Bullous pemphigoid (BP) and "Pemphigus diseases" (PD) can have overlapping clinical manifestations and accurate distinction is crucial for appropriate management.

AIMS: The study aimed at analyzing the utility of simple hematological markers of systemic inflammation like neutrophil-to-lymphocyte ratio (NLR), neutrophil-to-eosinophil ratio (NER), and platelet-to-lymphocyte ratio (PLR) in clinical decision making in the setting of clinical differentials of BP and PD in a particular case.

METHODS

This single-centre based retrospective observational analytical study included adult subjects newly diagnosed to have BP (n=66) or PD (n=53), confirmed with direct immune-fluorescence testing, over a period of six years. Blood counts performed using Coulter™ hematology analyser, at the time of their initial presentation, were retrieved from the hospital medical records, and the leucocyte ratios were calculated.

STATISTICAL ANALYSIS: The data were compared between the two groups, using Mann-Whitney U test and chi-square test /Fisher's exact test. ROC curve analysis was performed to estimate cut-off values.

RESULTS

The BP group had a significantly higher NLR, total leukocyte counts (TLC), absolute eosinophil counts (AEC), and absolute lymphocyte counts (ALC), and lower NER values compared to the PD group (P < 0.05). Areas under ROC for NLR, NER, TLC, AEC, and ALC were between 0.5 and 0.7. NLR ≥ 7, AEC ≥ 2055/cumm, and TLC ≥ 15,000/cumm had a specificity of 90.6, 100, and 100% respectively for identifying BP patients out of the two groups, but with a low sensitivity of 22.7, 21, and 22.7%, respectively.

CONCLUSIONS

NLR can be a valuable diagnostic adjunct in subtyping autoimmune bullous disorders, albeit in a small proportion of cases.