Inaccuracy of clinical phenotyping parameters for hypertensive nephrosclerosis

Area of Science:

• Nephrology
• Genetics
• Epidemiology

Background:

• Hypertension-induced end-stage renal disease (ESRD) is suspected to be heritable.
• Accurate phenotyping is crucial for identifying nephropathy susceptibility genes.
• The clinical hypertensive nephrosclerosis (HN) phenotype is not well-defined.

Purpose of the Study:

• To evaluate the prevalence of hypertensive nephrosclerosis (HN) in end-stage renal disease (ESRD) patients using stringent phenotyping criteria.
• To assess the accuracy of diagnoses on Health Care Financing Administration (HCFA) 2728 forms for HN.
• To determine the impact of phenotyping on identifying HN susceptibility genes.

Main Methods:

• Applied clinical parameters for HN phenotype, including family history of hypertension, left ventricular hypertrophy, proteinuria levels, and preceding hypertension.
• Utilized criteria from Schlessinger et al. (1994) and the AASK Trial Group (1997).
• Assessed ESRD patients (n=607) for HN, with a focus on African American and Caucasian populations.

Main Results:

• HN prevalence was significantly lower (1.5-13.5%) than indicated by HCFA 2728 forms (37%) when strict criteria were applied.
• Only 4% (Schlessinger criteria) and 28% (AASK criteria for African Americans) of randomly selected HN patients met the phenotyping standards.
• Renal biopsy data was largely inconsistent with HN, and many misdiagnosed cases were identified.

Conclusions:

• Hypertensive nephrosclerosis (HN) is less prevalent in ESRD populations than commonly believed when strict clinical criteria are employed.
• Many patients diagnosed with HN may have other, potentially treatable, renal diseases.
• Accurate and rigorous HN phenotyping is essential for genetic studies, likely requiring multi-center trials.