Abstract 1961 Poster Session II, Sunday, 5/2 (poster 188)

Background: ARPKD is one of the most common pediatric renal cystic diseases, yet limited clinical information is available to guide decision-making by clinicians and parents. More optimal patient management will require improved tools for prenatal diagnosis, detailed information about the clinical course, and identification of specific prognostic factors. While recent genetic studies have provided the basis for reliable, haplotype-based diagnosis in at-risk pregnancies, the natural history of ARPKD has not been well-characterized. The objective of the current investigation is to describe the baseline clinical features and survival characteristics of ARPKD patients drawn from tertiary care centers in the United States and Canada.

Methods: Data on ARPKD patients was collected retrospectively to January 1990. The diagnosis was based on either histopathology or the presence of two of the following criteria: 1) echogenic kidneys without gross cysts, 2) evidence of hepatic fibrosis, 3) biopsy-proven ARPKD in a sibling, 4) parental consanguinity. A total of 145 patients from 48 centers met the case definition for ARPKD and 68 have sufficient data for analysis. Survival times were calculated from date of birth to death or date of last contact for patients known to be alive. Kaplan-Meier curves were constructed and comparisons between subgroups were conducted by the log-rank test. Differences between categorical variables were examined by the X2 test and continuous variables were compared by t-test or Wilcoxin-rank sum tests. For all analyses, P value < 0.05 was considered statistically significant.

Results: Among all patients the survival rate at 30 days was 89.2% and at 1 year was 84.2%. For patients surviving the immediate neonatal period (n=58), the survival rate at 1 year was 96.2% for males and 96.4% for females (p=0.26). Nearly half of all patients (45%) were diagnosed either prenatally or within three days of birth. Neonatal interventions included ventilation (38.9%) and nephrectomy (14.5%). Over half the patients developed systemic hypertension (57.4%) with a median age of onset of 46 days. Less commonly associated morbidities included growth retardation (21.3%), chronic lung disease (9.7%), portal hypertension (11.5%), and urinary tract infections (3.10% girls vs. 9.4% boys, p=0.03). In this cohort, dialysis was initiated in 16.7% of the patients. Three boys received renal transplants and all remain alive at 8.4 years.

Conclusion: The one-year survival of ARPKD patients is better than generally perceived and there is wide variability in the expression of associated morbidities. With continued patient accrual to this database, the survival rates and clinical phenotypes of ARPKD patients will be more precisely defined. In addition, an analysis of interventions which may be independent prognostic factors for survival will feasible.