Clinical trial NCT00001978: Determination of Kidney Function
Official title: Determination of Glomerular Filtration Rate, Effective Renal Plasma Flow and Glomerular Capillary Wall Permselectivity
Study type: OBSERVATIONAL
Overall status: TERMINATED
Conditions: Kidney Disease
Proteinuria
Autoimmune / Connective Tissue Diseases
Keywords: Kidney Disease
Kidney Function Tests
Proteinuria
Lead sponsor: National Institutes of Health Clinical Center (CC)
Sponsor class: NIH
First posted: 2000-01-21
Enrollment: 456
Sex: ALL
Minimum age (years): 7
Standard ages: CHILD
ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Observational model: COHORT
Time perspective: PROSPECTIVE
Sampling method: NON_PROBABILITY_SAMPLE
Study population: Primary clinical and community sample

Brief summary: Much more about kidney disorders can be learned by determining kidney function. This research proposes to study the kidneys function by several parameters known as glomerular filtration rate (GFR), Renal Plasma Flow (RPF), and Glomerular Capillary Wall Permselectivity.

The study will select patients suffering from different types of kidney diseases. These patients will be selected based on the presence of significant amounts of protein in their urine (proteinuria).

Standard blood and urine tests are often unable to provide completely accurate information about the kidney. In order for researchers to have a more accurate idea of kidney function, they will use alternative tests. Test materials (para aminohippurate and inulin) will be injected into patients veins that provides information based on their filtration through the kidneys....

Detailed description: The study of various kidney disorders will be facilitated by determinations of true glomerular filtration rate and/or effective renal plasma flow employing inulin or non-radioactive iothalamate and/or para aminohippurate (PAH), respectively.

Selected patients with proteinuria will be asked to participate in studies of glomerular capillary wall permselectivity calculated from the fractional clearances of the endogenous proteins, albumin and IgG and from the fractional clearances of polydisperse neutral dextran with effective molecular radii ranging from 20-60 angstroms. To achieve this, low molecular weight dextran will be administered by slow IV injection immediately following the inulin or iothalamate and/or PAH priming doses.

Glomerular filtration rate, effective renal plasma flow and/or glomerular permselectivity can be measured simultaneously during a standard hydrated urinary clearance study. Timed urine and blood collections will be obtained, typically requiring a total of 60 to 90 minutes. The total test time, including pre-test hydration, is 4 to 5 hours.

Alternatively, glomerular filtration rate can be measured by one of two plasma clearance methods that do not require urine collections. For one method, a steady-state plasma concentration of iothalamate will be achieved in ambulatory patients by a 24-hour subcutaneous infusion of iothalamate using an insulin pump. For the second method, the decline in plasma concentration of iothalamate will be measured after an intravenous dose of iothalamate.

Eligibility criteria: * INCLUSION CRITERIA:

Ability to provide informed assent to all aspects of the study after full information is provided.

An indication to measure kidney function as accurately as possible in the context of an approved clinical protocol within the intramural programs of the National Institutes of Health:

* For minor subjects, a clinical indication will be required.
* For adult subjects, a clinical and/or research indication will be required.

EXCLUSION CRITERIA:

Pregnant females or nursing mothers will be excluded from all aspects of this study (at least until the infant is stable on a regimen of formula feeding).

Patients will not receive a test material if there is a history of allergy to that material.

Patients with a history of bronchial asthma or allergy to iodine-containing contrast material will not receive iothalamate.

Primary outcomes:
measure: Glomerular filtration rate
timeFrame: 4-5 hours
Secondary outcomes:
measure: Effective renal plasma flow
Other outcomes:
Locations:
city: Bethesda
country: United States
facility: National Institutes of Health Clinical Center, 9000 Rockville Pike
state: Maryland
Study officials:
affiliation: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
name: Meryl A Waldman, M.D.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Shemesh O, Golbetz H, Kriss JP, Myers BD. Limitations of creatinine as a filtration marker in glomerulopathic patients. Kidney Int. 1985 Nov;28(5):830-8. doi: 10.1038/ki.1985.205.
citation: Bauer JH, Brooks CS, Burch RN. Clinical appraisal of creatinine clearance as a measurement of glomerular filtration rate. Am J Kidney Dis. 1982 Nov;2(3):337-46. doi: 10.1016/s0272-6386(82)80091-7.
citation: Blythe WB. The endogenous creatinine clearance. Am J Kidney Dis. 1982 Nov;2(3):321-3. doi: 10.1016/s0272-6386(82)80089-9. No abstract available.