New Study Identifies Platelet-to-Hemoglobin Ratio as Powerful Predictor of Sepsis-Associated AKI
China: A new multicenter cohort study published in BMC Nephrology highlights the platelet-to-hemoglobin ratio (PHR) as a potential biomarker for predicting sepsis-associated acute kidney injury (SA-AKI), a life-threatening complication frequently observed in critically ill patients.
The research, led by Lina Zhao and colleagues from the Department of Critical Care Medicine at Tianjin Medical University General Hospital, underscores the need for reliable early indicators that can help clinicians identify patients at heightened risk.
The investigators noted that SA-AKI arises from complex mechanisms involving inflammation, coagulation abnormalities, and microcirculatory impairment. Given this interplay, the team explored whether PHR—a composite marker reflecting both hematological and inflammatory derangements—could serve as a practical early warning tool. To evaluate this, researchers analyzed data from two large ICU databases: MIMIC-IV and the eICU Collaborative Research Database.
A total of 8,215 adults with sepsis were included and categorized based on the presence or absence of AKI using KDIGO diagnostic criteria. Of these, 4,825 presented with SA-AKI, while 3,390 served as non-AKI comparators.
Multiple statistical models were used to adjust for illness severity, demographics, comorbidities, and laboratory parameters—including multivariable logistic regression, propensity score matching (PSM), and inverse probability weighting (IPW).
Key Findings:
- A higher PHR showed a strong correlation with increased odds of developing SA-AKI across all analytical approaches.
- In the fully adjusted model, each unit increase in PHR was associated with higher AKI risk (OR 1.06).
- This association remained consistent in PSM (OR 1.12) and IPW (OR 1.03) analyses, confirming the predictive strength of PHR.
- AKI incidence rose significantly when PHR values exceeded 20, and generalized additive modeling indicated a linear rise in mortality risk when PHR crossed 22.
- PHR did not demonstrate a strong link with AKI severity, but it showed notable prognostic value.
- As a standalone marker, PHR recorded an AUC of 0.845 for prognosis and 0.584 for diagnosis.
- Clinical performance improved substantially when PHR was integrated with ICU severity scores.
- Combined models with SOFA and SAPS-II displayed superior discrimination (AUC 0.906 for prognosis and 0.713 for diagnosis), outperforming individual parameters.
The authors emphasize that while PHR is not sufficient as a solitary predictor, it can serve as a valuable complementary marker that enhances existing models. Its simplicity and accessibility make it particularly appealing for busy critical care settings where rapid decision-making is crucial.
The study suggests that integrating PHR into early sepsis evaluation protocols may help flag high-risk patients who could benefit from closer hemodynamic monitoring or early interventions targeting coagulation and microcirculatory dysfunction.
"Overall, the findings support further prospective studies to validate PHR and explore how it can be incorporated into real-world clinical pathways for SA-AKI risk stratification," the authors concluded.
Reference:
Zhao, L., Zhang, Q., Li, Z. et al. Platelet-to-hemoglobin ratio as a novel prognostic biomarker in sepsis-associated AKI: a multicenter cohort study. BMC Nephrol (2025). https://doi.org/10.1186/s12882-025-04640-z
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