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

Abstract

Bullous pemphigoid (BP) and "Pemphigus diseases" (PD) can have overlapping clinical manifestations and accurate distinction is crucial for appropriate management. 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. 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. 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. 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. NLR can be a valuable diagnostic adjunct in subtyping autoimmune bullous disorders, albeit in a small proportion of cases.