CKiD Study Information
The design of the CKiD study is a prospective, observational cohort of children with chronic kidney disease. Exposures will be measured at baseline and scheduled annual follow-up visits will permit the subsequent updating of the exposures in cohort participants. Outcomes will also be assessed at the annual visits and they include: measures of kidney function; neurocognitive function; markers of risk factors for cardiovascular disease; growth and other co-morbid conditions. The study will use the power of the cohort design with regularly scheduled visits at which markers of disease progression will be measured under standardized procedures. Levels and longitudinal changes in markers will constitute the primary outcomes. The study will collect data on clinical events with primary interest in ESRD and death. Such events will provide time-to-event data to determine heterogeneity of times to ESRD in children with mild to moderate chronic kidney disease.
The CKiD study population will include three cohorts. Cohort 1 includes approximately 600 racially and ethnically diverse children, age 1-16 years old with mildly to moderately impaired kidney function, defined by an estimated GFR between 30 and 90 ml/min|1.73m2 by the Schwartz formula (sGFR). Cohort 2 includes approximately 300 children with more mildly impaired kidney function, defined as an estimated GFR between 45 and 90 by the updated Schwartz formula (eGFR). In addition, Cohort 2 was compromised of approximately 150 children with glomerular disease and approximately 150 children with non-glomerular causes of disease. Cohort 3 will include 190 children with non-glomerular diagnosis and duration of kidney disease less than 5 years but age at enrollment could range from 6 months to 16 years old.
- Age between 1 and 16 years (before 17th birthday) for Cohorts 1 and 2;age between 6 months and 16 years (before 17th birthday) for Cohort 3
- Estimated (based on SCr) Schwartz GFR between 30 and 90 ml/min|1.73m2 for Cohort 1 OR an estimated GFR between 45 and 90 ml/min|1.73m2 based on the updated Schwartz formula for Cohort 2
- Willingness and ability to provide informed consent and assent
- For Cohort 2, an equal distribution of children with glomerular and non-glomerular causes of disease were enrolled (i.e., 150 within each) and the study placed an upper limit of 60% for the percent of enrolled with non-glomerular disease.
- For Cohort 3, 190 children with non-glomerular diagnosis and duration of kidney disease less than 5 years will be enrolled.
Patients with the non-glomerular diagnoses listed below that meet the initial criteria (i.e., duration of kidney disease less than 5 years, and age between 6 months and 16 years old) are eligible and do not have to meet additional criteria:
- Branchio-oto-Renal Disease/Syndrome
- Medullary cystic disease/ juvenile nephronophthisis
- Methylmalonic Acidemia
- Polycystic kidney disease (Autosomal recessive)
However, all other patients with non-glomerular diagnoses will require at least two of the following conditions. All conditions except for abnormal imaging/biopsy must have occurred after the initial 6 months of life and must not be secondary to a current or resolving episode of Acute Kidney Injury (AKI):
- significant proteinuria,
- Age < 2 years old: urine protein to creatinine ratio > 0.5
- Age ≥ 2 years old: urine protein to creatinine ratio > 0.2
- Age < 2 years old: serum creatinine > 0.4 mg/dL
- Age ≥ 2 years old: eGFR < 90 ml/min|1.73m2 (eGFR=41.3 x height[meter]/creatinine[mg/dL])
- Documented hypertension noted in the medical record by the physician
- Current treatment of hypertension
- Blood pressure > 95th percentile for age and gender on at least two occasions
- Renal, other solid organ, bone marrow or stem cell transplantation
- Dialysis treatment within the past three months
- Cancer diagnosis or HIV diagnosis/treatment within last twelve months
- Current pregnancy or pregnancy within past twelve months
- Inability to complete major data collection procedures
- Current enrollment in a randomized clinical trial in which the specific treatment is unknown
- Not fluent in English or Spanish
- Plans to move out of area of any participating CKiD site (Families can be transferred to another CKiD site if they move)
- History of structural heart disease
- Genetic syndromes involving the central nervous system (e.g., Downs syndrome)
- History of severe to profound mental retardation (i.e., IQ less than 40, significant impairment in adaptive function and/or inability to independently execute self-care skills)
- For cohort 3, children who are expected to receive renal replacement therapy within 6 months of date of enrollment will not be recruited
Study Visit Schedule
The CKiD Study collects serum, plasma, urine, hair, nails and DNA samples during study visits.