The utility of systemic‐immune inflammation index for predicting the disease activation in patients with psoriasis

Abstract

To evaluate the utility of systemic-immune inflammation index (SII) in the management of patients with psoriasis. This retrospective case-control study was conducted on patients who were admitted to the dermatology outpatient clinic. Patients with psoriasis (n=71) were compared with a age and gender-matched control group (n=70) with other non-inflammatory dermatologic diseases. Study and control groups were compared in terms of clinical characteristics and SII values (neutrophil X platelet/lymphocyte). Afterwards, 50th percentile value (4.5) for psoriasis area severity index (PASI) was calculated for the study group. Two subgroups were formed according to PASI values: (1) PASI<4.5 group (n=36) and (2) PASI≥4.5 (n=35). Clinical characteristics and SII values were also compared between these two subgroups. Furthermore, SII values were compared according to the presence of scalp, joint, nail, and genital area involvement in the study group. Finally, a receiver operating characteristic (ROC) curve analysis was performed in order to assess the performance of SII in determining the activation of psoriasis in the study group. Significantly higher SII values were found in patients with psoriasis. PASI≥4.5 subgroup and patients with nail and genital involvement had also significantly higher SII values (P<.05). A cut-off value of 575.8 was calculated with 66.7% sensitivity and 66% specificity for psoriasis activation. SII may be used for the prediction of psoriasis activation.