Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease (CRISP)
Number of Subjects in Study Archive: 241
Study Design: Cohort
Conditions: Kidney Diseases, Polycystic Kidney Diseases
Duration: 2001 – ongoing
# Recruitment Centers: 4
Treatment: None, observational only
Available Genotype Data: Yes
Image Summary: Yes
Transplant Type: None
Does it have dialysis patients: No
The Consortium for Radiologic Imaging Studies of Polycystic Kidney Disease (CRISP) was established to develop and implement studies to test whether imaging techniques can provide accurate and reproducible markers of progression of renal disease in patients with polycystic kidney disease. Autosomal-dominant polycystic kidney disease (ADPKD) is characterized by gradual renal enlargement and cyst growth prior to loss of renal function; however, standard radiographic imaging has not provided the resolution and accuracy necessary to detect small changes in renal volume or to reliably measure renal cyst volumes. The CRISP cohort study longitudinally observed ADPKD individuals using high-resolution magnetic resonance (MR) imaging to determine if change in renal and cyst volumes can be detected over a short period of time, and if they correlate with decline in renal function early in disease.
Patients who were diagnosed with ADPKD and had a creatinine clearance of at least 70 mL/min were enrolled. Standardization studies were conducted at each participating clinical center. After, in the full-scale protocol, participants underwent standardized MR renal imaging, comprehensive clinical evaluation, evaluation of renal iothalamate clearance, and determination of 24-hour urinary albumin and electrolyte excretion. Stereology was used from T1-weighted images to quantify renal volume, and region-growing thresholding was used from T2-weighted images to determine cyst volume.
The study showed that MR measures of renal and cyst volume are reliable and accurate in patients with ADPKD. Kidney enlargement resulting from the expansion of cysts in patients with ADPKD was found to be continuous, quantifiable, and associated with the decline of renal function.
The current data package contains data through the CRISP 3 cycle.
The primary goal of the CRISP study group was to make prospective, longitudinal measurements of cyst and kidney growth in a large cohort of patients with ADPKD.
Increased renal volume, cyst volume, and % cyst volume were primary endpoints of the study. Changes in glomerular filtration rate (GFR), serum creatinine level, the reciprocal of serum creatinine, and blood urea nitrogen between baseline and termination of the study were also measured.
The study enrolled participants ages 15 to 46 years who met the following criteria:
- Diagnosis of ADPKD
- Actual or estimated creatinine clearance of at least 70 mL/min
- Serum creatinine level of ≤ 1.6 mg/deciliter for men and ≤ 1.4 mg/deciliter for women
Patients were ineligible if they had other medical conditions besides hypertension that could affect renal function (e.g., diabetes mellitus).
The study showed that MR measures of renal and cyst volume are reliable and accurate in patients with ADPKD. Findings indicated that renal-cyst and kidney enlargement is a continuous process in most patients with ADPKD and that the kidneys behaved as though the cysts within them enlarged at a steady rate specific to the patient.
Results showed a strong relationship between kidney volume at the beginning of the study and the subsequent change in the GFR, which provides support for the view that enlarging cysts have an important role in promoting the ultimate decline in GFR and renal function.