Neurotrophins (NTs) are a group of soluble growth factors with analogous structures and functions, identified initially as critical mediators of neuronal survival during development. Recently, the relevance of NTs has been confirmed by emerging clinical data showing that impaired NTs levels and functions are involved in the onset of neurological and pulmonary diseases. The alteration in NTs expression at the central and peripheral nervous system has been linked to neurodevelopmental disorders with an early onset and severe clinical manifestations, often named "synaptopathies" because of structural and functional synaptic plasticity abnormalities. NTs appear to be also involved in the physiology and pathophysiology of several airway diseases, neonatal lung diseases, allergic and inflammatory diseases, lung fibrosis, and even lung cancer. Moreover, they have also been detected in other peripheral tissues, including immune cells, epithelium, smooth muscle, fibroblasts, and vascular endothelium. This review aims to provide a comprehensive description of the NTs as important physiological and pathophysiological players in brain and lung development.

Background: Bronchiolitis is the most common cause of lower respiratory tract infection (LRTI) in the first year of life. We analyzed the association between complete blood count (CBC), c-reactive protein (CRP), and novel inflammatory indexes (NLR, PLR, MLR, ELR, LMR, NPR, LPR, LNR, PNR, SII, SIRI) in predicting bronchiolitis severity at hospital admission. Methods: We retrospectively collected data from 95 infants hospitalized for bronchiolitis in a third-level hospital during three epidemic seasons. Five outcomes of severity were analyzed: BRAS; pediatric intensive care unit (PICU) admission; ventilatory support; intravenous (IV) rehydration; and length of stay (LOS). Results: Lower age and weight at admission were statistically associated with four of the five severity outcomes. Prolonged LOS (≥6 days) was associated with high values of total white blood cells, lymphocytes, and eosinophils. Only three inflammatory indexes (PLR, MLR, and PNR) showed a significant association with one outcome (prolonged LOS). A new index (RBC/AiW/1000) was statistically associated with each severity outcome for a value > 350. Conclusions: We proposed a comprehensive analysis of the association between CBC, CRP, and novel inflammatory indexes and bronchiolitis severity. RBC/AiW/1000 could represent a future predictive marker of disease severity at hospital admission in infants with bronchiolitis.

Bronchopulmonary dysplasia (BPD) is a chronic lung condition in preterm infants characterized by impaired alveolar development, disrupted vascular growth, and persistent inflammation. These alterations, which often arise from early exposure to mechanical ventilation, oxygen toxicity, and infection, can lead to long-term structural and functional deficits in the developing lung. In adulthood, chronic obstructive pulmonary disease (COPD) represents a major cause of morbidity and mortality and is defined by progressive airflow obstruction, reduced respiratory capacity, and chronic inflammatory responses. Although traditionally considered a disease of adult smokers, growing evidence suggests that early-life respiratory insults play a key role in shaping long-term lung health. Recent studies reveal a biologically plausible link between BPD and later COPD, indicating that premature birth, impaired lung growth, and early inflammatory injury may predispose individuals to earlier or more severe COPD development. This review explores the shared molecular pathways connecting these conditions, focusing on overlapping inflammatory biomarkers such as IL1B, IL6, IL8, TNF, TGFB, and VEGF, which collectively reflect persistent dysregulation of immune and repair mechanisms. Additionally, common genetic variants, including SERPINA1 and HHIP, may contribute to susceptibility across the lifespan. Emerging biomarkers—such as PRMT7, cathelicidin/LL-37, CRISPLD2, and GDF15—offer further insight into disease progression. Identifying these shared markers may ultimately improve early detection and help clinicians pinpoint infants with BPD who face an elevated risk of developing COPD later in life.

Background: Hemophagocytic lymphohistiocytosis (HLH) is a rare and often life‐threatening hyperinflammatory disorder, mainly caused by infections, malignancies, or autoimmune diseases. Influenza A (H1N1) has occasionally been linked to pediatric HLH cases. Rhabdomyolysis, relatively uncommon in children, can be a complication of viral infections, including influenza. To our knowledge, this is the first reported pediatric case where H1N1 infection was complicated by both HLH and severe rhabdomyolysis. Case Presentation: We describe the case of a previously healthy 4‐year‐old girl who was hospitalized with high fever, gastrointestinal symptoms, and marked somnolence. Blood tests revealed severe rhabdomyolysis (creatine phosphokinase [CPK] > 100,000 U/L) and metabolic acidosis. Influenza A (H1N1) infection was confirmed by a nasopharyngeal swab. Despite prompt initiation of antiviral and supportive therapies, the patient developed persistent fever, pancytopenia, hyperferritinemia, hypertriglyceridemia, hepatosplenomegaly, and cardiac involvement. Bone marrow biopsy confirmed hemophagocytosis, according to HLH‐2004 criteria. She was treated with high‐dose methylprednisolone and intravenous immunoglobulin (IVIG), with rapid clinical improvement. The patient was discharged after 16 days without sequelae. Conclusions: This case describes a rare but severe presentation of Influenza A infection in a child, complicated by both HLH and severe rhabdomyolysis. The combination of a hyperinflammatory condition and multiorgan dysfunction highlights the importance of early recognition and multidisciplinary management. Our case is the first documented pediatric case of H1N1‐related HLH with severe rhabdomyolysis in pediatric populations, and a review of the literature confirms the rarity of this association. Clinicians should maintain a high index of suspicion for HLH in children with persistent fever, cytopenia, hyperferritinemia, and organ involvement during viral infections. The potential coexistence of rhabdomyolysis should be considered in the presence of persistent high CPK levels to prevent serious complications such as acute kidney injury.