Longitudinal changes in inflammatory markers and body weight in adults with primary immunodeficiency receiving immunoglobulin replacement therapy: A retrospective cohort study

Immunoglobulin replacement therapy (IgRT) is the cornerstone of treatment for adults with primary immunodeficiency [primary immunodeficiency diseases (PID)]. Its role in infection prevention is well established. However, its effects on systemic inflammation and metabolic parameters remain incompletely understood. This study evaluated one-year changes in inflammatory indices and body weight in adults with PID receiving intravenous (IVIG) or subcutaneous (SCIG) immunoglobulin therapy. This retrospective study included 32 adults with PID. The cohort consisted predominantly of patients with common variable immunodeficiency, along with selected cases of Good syndrome and CTLA-4 insufficiency. Patients received intravenous immunoglobulin (IVIG) (n = 22) or SCIG (n = 10). Inflammatory markers [neutrophil-to-lymphocyte ratio (NLR), C-reactive protein (CRP), neutrophil count] and body weight were assessed at baseline and after 12 months. Non-parametric tests were used due to sample size. Body weight increased significantly in both the IVIG (P = .01) and SCIG (P = .011) groups. In the IVIG group, CRP (P = .005), absolute neutrophil count (P = .017), and NLR (P = .034) decreased significantly. In the SCIG group, body weight increased significantly. However, changes in inflammatory markers were not significant. Platelet counts decreased (P = .012), while WBC counts increased (P = .016). IgRT was associated with increased body weight in adults with PID. This was consistent across both IVIG and SCIG groups. IVIG was also associated with reductions in inflammatory markers. These findings suggest that IgRT may have effects beyond infection prevention. Body weight may be a useful parameter during follow-up of adult PID patients.