Low HALP score was independently and non-linearly associated with stroke-associated pneumonia in acute ischemic stroke, with an exploratory threshold near 27.7 below which each log2-unit increase in HALP was associated with a 53% lower SAP risk.
Stroke-associated pneumonia occurred in 21.3% of acute ischemic stroke patients in this cohort.
HALP scores were significantly lower in AIS patients who developed SAP compared to those who did not.
Each 1-unit increase in log2-HALP was independently associated with a 29% lower risk of SAP after full multivariable adjustment.
Patients in the highest HALP quartile had significantly lower SAP risk compared to those in the lowest quartile.
A non-linear association was identified between HALP and SAP risk, with an exploratory threshold at approximately HALP = 27.7.
Adding HALP to the A2DS2 score produced a statistically significant but modest improvement in SAP discrimination.
This research suggests that a blood-test-based score called the HALP score — which combines measures of hemoglobin (related to red blood cells), albumin (a protein reflecting nutrition), lymphocytes (immune cells), and platelets (clotting cells) — is linked to the risk of developing pneumonia after a stroke. Among 1,766 stroke patients studied over five years, about 1 in 5 developed stroke-associated pneumonia, and those who did had notably lower HALP scores than those who did not. Even after accounting for other health factors, patients with lower HALP scores were significantly more likely to develop pneumonia following their stroke. An important nuance the researchers found is that this relationship is not simply a straight line — it is non-linear. The protective association of a higher HALP score appeared most strongly in patients whose HALP was below approximately 27.7; above that level, higher HALP scores did not appear to offer additional protection against pneumonia. This suggests that patients with very low HALP scores at admission may represent a particularly high-risk group worth monitoring closely. Adding HALP to an existing stroke-pneumonia risk tool (the A2DS2 score) modestly improved its ability to identify which patients would go on to develop pneumonia. This research suggests that routine blood tests taken shortly after stroke admission could be used to calculate a HALP score and potentially help clinicians identify patients at higher risk for this serious complication. Because this was a retrospective study at a single center, the findings — particularly the specific threshold value of 27.7 — need to be validated in future, independent studies before they could inform clinical practice.
Wu Z, Sun Q, Zhan J, Yang M, Duan T, Pan H, et al.. (2026). Low hemoglobin-albumin-lymphocyte-platelet score as a risk marker for stroke-associated pneumonia in acute ischemic stroke: a retrospective cohort study.. Frontiers in neurology. https://doi.org/10.3389/fneur.2026.1866716