====== Platelet lymphocyte ratio ======

[[Platelet]] lymphocyte ratio (PLR) has been identified as a biomarker of inflammation and proved to be significant in prognosis. Some studies have shown a relationship between poor prognosis and low [[lymphocyte]] count and high [[platelet]] count in acute coronary syndrome.
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Experimental studies have shown that [[leukocyte]] infiltration and [[platelet activation]] occur immediately after [[aneurysmal subarachnoid hemorrhage]] (SAH) and that decreased leucocyte counts can improve early [[cerebral ischemia]], delayed cerebral [[vasospasm]], and subsequent functional outcome
((Friedrich V, Flores R, Muller A, et al. Reduction of
neutrophil activity decreases early microvascular
injury after subarachnoid haemorrhage.
J Neuroinflammation. 2011;8:103)).

It has been reported that patients with [[traumatic subarachnoid hemorrhage]] have increased [[leukocyte]] counts on hospital admission, which is an important parameter of severity of injury and an additional marker of neurological outcome in patients with severe head trauma
((Rovlias A, Kotsou S. The blood leukocyte count and
its prognostic significance in severe head injury. Surg
Neurol. 2001;55(4):190–196.)).

A retrospective examination was made of patients with SAH diagnosed secondary to isolated head trauma, isolated anterior communicating artery aneurysm rupture, and angiography-negative SAH. Age, gender, Glasgow Coma Scale (GCS) scores, and Fisher's grade scores, Glasgow Outcome Scale (GOS) scores, leukocyte count, neutrophil count, lymphocyte count, platelet count, [[Neutrophil to lymphocyte ratio]] (NLR) and [[platelet lymphocyte ratio]] results (PLR) were evaluated.

NLR and PLR values, which were similar in patients with spontaneous SAH, were significantly high in patients with traumatic SAH. NLR and PLR values could be 80% sensitive and 75% specific for distinguishing traumatic SAH from spontaneous SAH. Eosinophil count was lower in patients with angiography-negative SAH and patients with aneurysmal SAH than in patients with traumatic SAH. Initially measured GCS score, Fisher's grade score, eosinophil, neutrophil and lymphocyte counts could be prognostic in all patients with SAH. Moreover, it was concluded that the initially measured number of eosinophils might be directly related to patient prognosis. The eosinophil count was generally found to be high in traumatic SAH patients and it was observed that this parameter could be predictive for these patients. Lymphocyte count and NLR values could be prognostic markers in patients with angiography-negative SAH.

[[Neutrophil to lymphocyte ratio]] (NLR) , [[platelet lymphocyte ratio]] results (PLR) and [[eosinophil]] count values could be predictive for etiological factors (traumatic SAH or spontaneous SAH) of patients who were admitted unconscious to the emergency room with SAH detected on radiological imaging
((Ogden M, Bakar B, Karagedik MI, Bulut IU, Cetin C, Aydin G, Kisa U, Ozveren
MF. Analysis of biochemical laboratory values to determine etiology and prognosis
in patients with subarachnoid hemorrhage: a clinical study. Neurol Res. 2018 Nov 
10:1-12. doi: 10.1080/01616412.2018.1545414. [Epub ahead of print] PubMed PMID:
30417744.
)).