Improving Scientific Rigor of Renal Clinical Endpoints for Sickle Cell Anemia

Study Overview
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Brief Summary
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The investigators will attempt to develop a more accurate equation to estimate eGFR in pediatric and adult sickle cell patients

Detailed Description
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200 pediatric and 200 adult SCA participants will undergo mGFR using iohexol at baseline and at one year. On the same day, participants will undergo clinical and laboratory variables important for developing an eGFR equation. From baseline data, the investigators will perform a training and validation cohort of biologically relevant predictor variables to develop a novel equation. Then the investigators will compare the novel SCA eGFR equation to the established eGFR equation. From one year data, the investigators will determine the longitudinal concordance between pediatric and adult novel and standard eGFR equations with mGFR and variables that may alter longitudinal inferences. In a subset of 30 adult participants, the investigators will also evaluate the correlation between mGFR using iohexol and a novel measure of mGFR that is more time efficient

Official Title
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Improving Scientific Rigor of Renal Clinical Endpoints for Sickle Cell Anemia

Conditions
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Sickle Cell Disease, Renal Disease, Glomerular Disease

Intervention / Treatment
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* Diagnostic Test: iohexol GFR


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: SCA patients (HbSS and SB0 thalassemia) Age: 5.0-50.0 at enrollment Exclusion Criteria: Recent SCA complication associated with hospitalization (within 30 days) or ED visit (within 14 days) Current AKI defined as >0.3mg/g increase in SCr from prior visit Known history of anaphylaxis with contrast agent or known pregnancy

Ages Eligible for Study
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Minimum Age: 5 Years
Maximum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Pediatric SCA<br>We will develop a novel eGFR equation in 200 pediatric participants | Diagnostic Test: iohexol GFR<br>* We will perform mGFR in 400 SCA patients<br>|
| Adult SCA<br>We will develop a novel eGFR equation in 200 adult participants | Diagnostic Test: iohexol GFR<br>* We will perform mGFR in 400 SCA patients<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To develop a novel SCA-specific eGFR equation and compare with existing eGFR equations validated for the general population | The investigators will use biologically relevant variables to develop a new equation for eGFR in pediatric and adult sickle cell patients | 5 years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| To determine the longitudinal concordance between pediatric and adult novel and standard eGFR equations with mGFR and variables that may alter longitudinal inferences. | To compare the concordance between eGFR and mGFR from baseline to one year | 5 years | 
| To test the correlation of the novel mGFR method using VFI FAST and iohexol mGFR. | To perform a 3 hour mGFR and compare this mGFR to the 6 hour mGFR (iohexol) | 5 years |