24-h versus PET samples: Which is better for quantification of peritoneal protein loss?
Portugal: Peritoneal protein loss (PPL) quantification may be expressed in accordance with a timely collection (24-h measurement or 4-h PET assessment) and as a concentration.
A recent study in the Karger journal Blood Purification has found that measurements of a 24-h sample might be closer to the clinical status and prognosis of the patient, indicating opportunities for therapy intervention. Further, the researchers found that the quantification of PET protein loss should be regarded as a marker of peritoneal membrane intrinsic permeability.
Guedes A. Malho and colleagues from Portugal aimed to compare the quantification methods of 24-h and 4-h collections. The study included 81 prevalent peritoneal dialysis patients. Registration of demographics and clinical and bioelectrical impedance features was done. Measurement of PPL (4-h PET and 24-h results) was done and peritoneal protein clearance was calculated. A linear regression model was performed.
Based on the study, the researchers found the following:
- Age and continuous ambulatory peritoneal dialysis (compared to cycler) were positively associated with greater PPL on 24-h collections.
- Neither cardiovascular disease, hypertension, diabetes nor the comorbidity Charlson Index was significantly associated with PPL.
- There was a consistent univariable relationship with D/P creatinine, whichever sampling method was used.
- Only 24-h measurements of PPL correlated with body composition variables.
- In multiple linear regression analysis, D/P creatinine association with PPL stands out.
- On the other hand, 24-h determinations (in grams or clearance) were associated with overhydration.
- PET protein quantification was associated with peritoneal creatinine clearance.
The researchers wrote, "different methods sign different pathophysiological pathways. Quantification of PET protein loss should be regarded as a marker of peritoneal membrane intrinsic permeability."
"Measurements of a 24-h sample might be closer to patients' clinical status and prognosis, signalizing opportunities for therapy intervention," they conclude.
Reference:
The study titled, "Protein Loss in Peritoneal Effluent: Different Meaning for 24-h versus PET Samples," was published in the journal Blood Purification.
DOI: https://doi.org/10.1159/000525502
