p-Cresyl sulphate and indoxyl sulphate predict progression of chronic kidney disease.
BACKGROUND
Indoxyl sulphate (IS) and p-cresyl sulphate (PCS) are uraemic toxins that have similar protein binding, dialytic clearance and proinflammatory features. However, only a few prospective studies have evaluated possible associations between these two retained solutes and renal disease progression in chronic kidney disease (CKD) patients.


METHODS
This prospective observational study evaluated independent associations between serum total IS and PCS with renal progression in a selected cohort of patients having different stages of CKD. Baseline PCS and IS were correlated with renal progression [defined as decrements in estimated glomerular filtration rate (eGFR) > 50% from baseline or progression to end-stage renal disease (ESRD)] and death during a follow-up period of 24 months.


RESULTS
Of 268 patients, 35 (13.1%) had renal progression and 14 (5.2%) died after a mean follow-up of 21 ± 3 months. Univariate Cox regression analysis followed by multivariate analysis showed that high-serum PCS levels were associated with renal progression and all-cause mortality independent of age, gender, diabetes status, albumin levels, serum IS, serum creatinine, Ca × P product, intact parathyroid hormone, haemoglobin or high-sensitivity C-reactive protein level. Serum IS was only associated with renal progression; however, the predictive power of serum IS was weakened when serum PCS was also present in the analytical model.


CONCLUSIONS
In addition to traditional and uraemia-related risk factors such as renal function, serum IS and PCS levels may help in predicting the risk of renal progression in patients having different stages of CKD.
Wu
I-Wen
IW
Department of Nephrology, Chang Gung Memorial Hospital, Keelung, Taiwan.
Hsu
Kuang-Hung
KH
Lee
Chin-Chan
CC
Sun
Chiao-Yin
CY
Hsu
Heng-Jung
HJ
Tsai
Chi-Jen
CJ
Tzen
Chin-Yuan
CY
Wang
Yen-Chih
YC
Lin
Ching-Yuang
CY
Wu
Mai-Szu
MS
D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D015331:Cohort Studies; D003404:Creatinine / Q000097:blood; D003408:Cresols / Q000097:blood*; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D005919:Glomerular Filtration Rate; D006801:Humans; D007200:Indican / Q000097:blood*; D007676:Kidney Failure, Chronic / Q000097:blood*; D007677:Kidney Function Tests; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D012307:Risk Factors; D013463:Sulfuric Acid Esters / Q000097:blood*; D015996:Survival Rate; D014511:Uremia / Q000097:blood*
D015415:Biomarkers; D003408:Cresols; D013463:Sulfuric Acid Esters; C408690:4-cresol sulfate; D003404:Creatinine; D007200:Indican