Impact of prognostic nutritional index on clinical outcomes in hereditary angioedema: a single-center experience

Abstract

Background/Aim: This study aims to evaluate the impact of the Prognostic Nutritional Index (PNI) on clinical outcomes in hereditary angioedema (HAE) patients. HAE is a rare genetic disorder (prevalence approximately 1:50,000) marked by recurrent episodes of severe swelling due to a deficiency in the C1 inhibitor (C1-INH) protein, affecting the complement and contact systems. PNI, a measure of nutritional and immune status, has been used to predict clinical outcomes in various chronic diseases, but its role in HAE remains unclear. Methods: A single-center retrospective cohort of 60 patients was analyzed. Clinical characteristics and PNI were assessed and calculated using the formula: [Serum Albumin (g/L)] + [5 × Peripheral Blood Lymphocyte Count (×10⁹/L)]. Patients were stratified into low and high PNI groups based on a cut-off value of 51.725, derived from receiver operating characteristic (ROC) curve analysis (AUC = 0.902, p < 0.001). Statistical significance was set at p < 0.05. Results: Low PNI was significantly associated with increased attack frequency (p < 0.001), extended diagnostic delays (p = 0.022), and greater laryngeal (p = 0.003) and gastrointestinal involvement (p = 0.005). Furthermore, low PNI was negatively correlated with monthly attack frequency (Spearman’s rho =-0.653, p < 0.001) and positively correlated with the C1-INH function (Spearman’s rho = 0.408, p = 0.001). Conclusion: These findings underscore the importance of incorporating nutritional evaluations into HAE management, as poor nutritional status may exacerbate disease severity. Further prospective studies are needed to validate these associations and explore nutritional interventions as a complementary strategy in HAE treatment.