MPO and obesity due to melanocortin 4 receptor deficiency: Neutrophils present dual effect in the pathogenesis of PD: the protective role involves the maintenance of tissue homeostasis and the destructive role involves the inflammatory bone loss.33 Neutrophils are involved in activation and differentiation of osteoclasts, multinucleated cells involved in bone resorption, through the RANKL membrane.41 Obesity models resulted in increased MPO activity in periodontal tissues, suggesting that neutrophils may exert an impact on obesity-induced alveolar bone loss.