The Impact of Age of Diagnosis in Children with Primary Ciliary Dyskinesia.

Rationale: The typical symptoms for primary ciliary dyskinesia (PCD) manifest after birth and in early infancy, however diagnosis is often not confirmed during infancy. There is currently a lack of evidence in PCD regarding the impact of the age of diagnosis on clinical outcomes.

Objective: To determine whether early diagnosis is related to improved long-term outcomes.

Method: This was a retrospective study of patients diagnosed with PCD between 2000 to 2022. We divided our cohort to three groups according to the age of diagnosis. 1) early diagnosis (<1 year); typical diagnosis (1-7 years) and late diagnosis (8-14 years). We compared various clinical long-term outcomes between the groups.

Results: Over the study period, 110 patients were included in the analysis, with 41 patients in the early diagnosis group, 35 in the typical diagnosis group and 34 patients in the late diagnosis group. The presence of unexplained neonatal respiratory distress (NRDS) and organ laterality defect were higher in the early diagnosis group with rates between the early, typical, and late diagnosis groups for NRDS (80% vs 53% vs 61%, p=0.045) and laterality defect (64% vs 50% vs 18%, p<0.001). At the end of the first decade of life, patients in the early diagnosis and the typical age of diagnosis had better forced expiratory volume in 1 second (FEV1), compared to the late diagnosis group (93.5% and 93.1% vs 80.2%, P=0.002), respectively, but there was no significant change in the annual rate of decline between the groups once diagnosis was confirmed. Patient diagnosed late had significantly higher rates of pulmonary exacerbations (Pex) compared to typical age (1.95 vs 0.75 Pex/year, p<0.01) Conclusion: Late diagnosis (>8 years) was associated with lower FEV1 throughout childhood, although once diagnosed, the annual rate of decline was not different. These findings demonstrate the negative effect of delayed diagnosis in pediatric PCD.