Clinical Experience with Inosine Pranobex in Pediatric Acute Respiratory Infections with Comorbidities: A Case Series from a Specialised Centre.

Background: Acute respiratory infections (ARIs) pose a significant clinical challenge in paediatric populations, especially in children with comorbidities who may exhibit underlying immune dysregulation. Inosine pranobex (IP) is an immunomodulatory agent that enhances T-lymphocyte and Natural Killer (NK) cell function, offering a targeted therapeutic rationale for such cases. Objective: This study aimed to retrospectively describe the clinical characteristics, immunological profiles, and outcomes of paediatric patients with complex, PCR-confirmed viral ARIs and significant comorbidities, for whom adjunctive therapy with IP was initiated based on clinical judgment. Methods: This retrospective case series analysed data from 14 paediatric patients hospitalised at a specialised centre (National Institute of Paediatric Tuberculosis and Respiratory Diseases in Dolny Smokovec, Slovakia). Cases were selected based on PCR-confirmed viral ARI, a history of recurrent infections, significant comorbidities, and initiation of IP therapy. The indication for IP was guided by the treating physician in cases of severe, prolonged, or recurrent disease course, where immune dysregulation was suspected, often supported by prior immunophenotyping. Results: A frequent observation in this cohort was the presence of baseline cellular immune alterations with a frequent observation of baseline cellular immune alterations, most notably the depletion of natural killer (NK) cells. NK cell depletion was identified in half of the patients (7/14). Following the initiation of treatment regimens that included adjunctive IP, clinical stabilisation or improvement was observed in all 14 patients included in the study. The therapy was well tolerated, with no reported adverse events attributable to IP. Conclusions: This case series highlights the common presence of cellular immune alterations in children with complex ARIs. While the observational nature of this study precludes any conclusions about causality, the favourable clinical course, safety profile, and strong immunological rationale support the need for prospective controlled trials to evaluate the role of IP in this specific high-risk paediatric population.