Researchers looked at whether a routine blood measure called the neutrophil-to-lymphocyte ratio (NLR) might be linked to peritoneal dialysis-associated peritonitis. The study included 178 patients on peritoneal dialysis at a single center, comparing 89 people who had peritonitis with 89 matched controls.
They found that a higher NLR was independently associated with an increased risk of peritonitis. For each one-unit increase in the natural log of NLR, the odds of peritonitis were about 2.25 times higher. The highest NLR group also showed a consistent positive association with peritonitis risk.
No safety issues were reported because the study only measured a blood ratio. The main reason to be careful is that this was a small, retrospective, single-center study, and matched case-control designs can introduce selection bias. Observational findings like these need validation in prospective studies before any clinical use.
What readers should take from this is that NLR may serve as a biomarker to help predict future peritonitis risk, but it does not prove cause and effect, and it should not guide treatment decisions on its own.