A 2022 human study investigated three measurements of the CBC with Differential/Platelet test:

“This study explored the relationship between the systemic immune-inflammation index (SII) and stroke prognosis. SII was defined as neutrophils × platelets/lymphocytes. Neutrophils and lymphocytes are involved in the inflammatory and immune response, whereas platelets have a primary role in the thrombo-inflammation of stroke.

Patients were divided into four groups according to SII values: quartile (Q)1 <366; Q2 366–533; Q3 534–799; and Q4 ≥800. As the SII quartile increased, patients with acute ischemic stroke were more likely to have poor functional outcomes during follow-up.

Although age, smoking status, and alcohol consumption are risk factors, and female estrogen is a protective factor for stroke, we did not identify subgroups specifically being affected by these factors. Even if we adjusted our model for factors identified by previous studies as immune-inflammation markers that might affect prognosis, such as the high-sensitivity C-reactive protein level, our results still suggested that SII is closely related to short- and long-term prognosis of patients with acute ischemic stroke.

As a new type of immune-inflammation index, the SII integrates neutrophils, platelets, and lymphocytes, and can reflect the balance of the systemic immune response and inflammatory response.”

https://www.aging-us.com/article/204228/text “Correlation of the systemic immune-inflammation index with short- and long-term prognosis after acute ischemic stroke”