Renal ultrasonographic evaluation in children at risk of autosomal dominant polycystic kidney disease.

BACKGROUND: To date, there are no criteria for diagnosing autosomal dominant polycystic kidney disease (ADPKD) in at-risk children 15 years or younger. STUDY DESIGN: Longitudinal (retrospective cohort study). SETTING & PARTICIPANTS: 420 children (mean age, 8.3 +/- 4.2 years) with a family history of ADPKD were studied. MEASUREMENTS: Renal ultrasonography was performed for cyst detection. Urine protein was measured using two 24-hour urine collections. Glomerular filtration rate was calculated using the Schwartz formula. Blood pressure measurements were performed in the arm with the highest blood pressure, using an appropriate cuff size. Standard 2-dimensional and Doppler echocardiography was performed for measuring left ventricular mass index. PREDICTORS: None. OUTCOME: Presence of renal cysts. RESULTS: Renal cysts were detected in 193 children and no cysts were detected in 227 children. In children with renal cysts, 150 had bilateral and 43 had unilateral cysts. Children with bilateral cysts had larger kidneys and more hypertension than children with unilateral or no cysts. Follow-up in 77 children 15 years or younger showed bilateral cysts in 14 and unilateral cysts in 4 of the children who had no detectable renal cysts using ultrasonography at baseline. Similar follow-up of 26 children 15 years or younger with unilateral cysts detected at baseline showed bilateral cysts in 17 children using ultrasonography. By 15 years of age, 181 patients in the total group of 420 showed bilateral cysts. Overall, 193 of 304 children (63.4%) who had follow-up at any age developed bilateral cysts detected using ultrasonography. LIMITATIONS: Follow-up unavailable for all participants. CONCLUSION: The present results in 420 at-risk children with ADPKD 15 years or younger detected bilateral renal cysts using ultrasonography in 181 of the children who had a family history of this genetic disease.

Expression and synthesis of bone morphogenetic proteins by osteoclasts: a possible path to anabolic bone remodeling.

Skeletal remodeling is a finely orchestrated process coupling bone formation to bone resorption. The dynamics of coupling is regulated by the microenvironment at the bone remodeling site, which in turn is influenced by the intercellular communication between cells like osteoclasts and osteoblasts. Understanding the dynamics of coupling is important in devising new therapeutic approaches to the treatment of skeletal diseases characterized by disturbances in the bone remodeling process. In this study, we report the localization of bone morphogenetic proteins (BMPs) in osteoclasts generated from primary cocultures of bone marrow cells from mouse femur and tibia with mouse calvarial osteoblasts, using immunocytochemistry and in situ hybridization. Positive staining was seen in osteoclasts for BMP-2, -4, -6, and -7. Real-time PCR was used to quantitatively confirm the expression of transcripts for BMP-2, BMP-4, and BMP-6 mRNA in murine osteoclasts. Finally, the presence of BMP-2, -4, -6, and-7 proteins was confirmed in osteoclast lysates by Western blotting. Overall, our data suggest a possible direct role for osteoclasts in promoting bone formation via expression and synthesis of BMPs, which then would play an important role in promoting the recruitment, proliferation, and differentiation of osteoblasts at bone resorption sites.