Urinary CKD273 predicts early renal damage in primary hypertension

A classifier developed based on 273 urinary peptides (CKD273) can predict new-onset proteinuria in patients with primary hypertension and be used to diagnose those with early renal injury, reports a study. This predictor contributes to the early prevention and treatment of hypertensive nephropathy.

A team of investigators compared the level of urinary CKD273 in healthy individuals, hypertensive plus normoalbuminuric patients, and those with hypertension and albuminuria. They also obtained 22 baseline data, including age, sex, renal function, and hypertensive fundus lesions. Patients diagnosed with hypertension, albuminuria, and normal renal function were followed-up.

Based on the follow-up results, the investigators then calculated and analysed the cutoff value of CKD273 in predicting hypertensive renal injury in both the high- and low-risk groups of hypertensive patients for its performance in detecting early hypertensive renal injury.

A total of 310 participants were included. Average urinary CKD273 levels were significantly greater in patients with hypertension than in normotensive individuals. Overall, 147 hypertensive patients with normal albuminuria were followed-up for a mean of 3.8 years.

Of the participants, 35 had urinary albumin-to-creatinine ratio (uACR) of at least 30 mg/g for three consecutive times. Based on the receiver-operating characteristic (ROC) curve, the cutoff value of urinary CKD273 for evaluating new-onset proteinuria in hypertensive patients was 0.097. Using this cutoff value, 39 and 108 patients were included in the high- and low-risk groups, respectively.

Patients in the high- vs low-risk group displayed significantly longer hypertension duration, higher proportions of hypertensive fundus lesions and at least 30 mg/g uACR, and higher levels of homocysteine (Hcy), cystatin C (CysC), beta-2 microglobulin (β2-MG), and uACR. Among high-risk patients, 76.9 percent had markedly higher new-onset proteinuria than their low-risk counterparts.

Furthermore, correlation analysis revealed a positive relationship between urinary CKD273 and uACR (r, 0.494; p=0.000). On Cox regression analysis, the high-risk group showed a significantly higher incidence of new-onset albuminuria than did the low-risk group. The areas under the curve of CKD273, Hcy, β2-MG, and CysC were 0.925, 0.753, 0.796, and 0.769, respectively.

“Renal diseases caused by primary hypertension are often asymptomatic without sensitive markers for early diagnosis and prediction, easily progressing to severe and irreversible renal damage in patients with clinical manifestations,” the investigators said.