Role of blood platelets in infection and inflammation

Could the platelet-to-lymphocyte ratio be a novel marker for predicting invasiveness of cervical pathologies?

PURPOSE

To determine whether the preoperative platelet to lymphocyte ratio (PLR) could predict invasiveness of cervical pathologies.

MATERIALS AND METHODS

Patients with preinvasive and invasive diseases were reviewed retrospectively, over a nine-year period, 2005-2014. The pathological records and completed blood counts of the patients were collected and recorded in the SPSS program. Patients were divided in two groups, preinvasive and invasive.

RESULTS

The median PLR was significantly higher in the invasive group than in the preinvasive group (p=0.03). There was a correlation between invasion of cervical cancer and white blood cell count, red cell distributing width (RDW), neutrophil-lymphocyte ratio (NLR), and PLR.

CONCLUSIONS

This study showed that patients with uterine cervical cancer may present with leukocytosis, increased RDW, NLR and PLR. These cheap and easily available parameters, especially PLR, may provide useful information about the invasiveness of cervical lesions.

Association of the Preoperative Neutrophil-to-ymphocyte Count Ratio and Platelet-to-Lymphocyte Count Ratio with Clinicopathological Characteristics in Patients with Papillary Thyroid Cancer

BACKGROUND

Several inflammatory biomarkers, especially a high preoperative neutrophil-to-lymphocyte count ratio (NLR) and platelet-to-lymphocyte count ratio (PLR), are known to be indicator of poor prognosis in several cancers. However, very few studies have evaluated the significance of the NLR and PLR in papillary thyroid cancer (PTC). We evaluated the association of the preoperative NLR and PLR with clinicopathological characteristics in patients with PTC.

METHODS

This study included 1,066 female patients who underwent total thyroidectomy for PTC. Patients were stratified into 4 quartiles by preoperative NLR and PLR. And the combination of preoperative NLR and PLR was calculated on the basis of data obtained value of tertile as follows: patients with both an elevated PLR and an elevated NLR were allocated a score of 2, and patients showing one or neither were allocated a score of 1 or 0, respectively.

RESULTS

The preoperative NLR and PLR were significantly lower in patients aged ≥45 years and in patients with Hashimoto's thyroiditis. The PLR was significantly higher in patients with tumor size >1 cm (P=0.021).When the patients were categorized into the aforementioned four groups, the group with the higher preoperative PLR was found to have a significantly increased incidence of lateral lymph node metastasis (LNM) (P=0.018). However, there are no significant association between the combination of preoperative NLR and PLR and prognostic factors in PTC patients.

CONCLUSION

These results suggest that a preoperative high PLR were significant associated with lateral LNM in female patients with PTC.

Changes in neutrophil/lymphocyte and platelet/lymphocyte ratios after chemotherapy correlate with chemotherapy response and prediction of prognosis in patients with unresectable gastric cancer

The aim of the study was to investigate the application value of neutrophil to lymphocyte ratio (NLR) and the platelet to lymphocyte ratio (PLR) in the prediction of chemotherapy response and prognosis in patients with advanced gastric cancer. In total, 120 patients with unresectable gastric cancer were included and separated into two groups according to the median values of NLR or PLR (NLR low: <4.62 or NLR high: ≥4.62 and PLR low: <235 or PLR high: ≥235, respectively). Low baseline NLR level correlated with improved clinicopathological characteristics, including smaller tumor size, well differentiation and less metastasis. Low baseline PLR level also associated with less metastasis. Patients with a low baseline level of NLR or PLR had an improved response to chemotherapy. Patients with a higher baseline NLR and PLR had decreased progression-free survival (PFS) and overall survival (OS) ratios. Alterations in the NLR and PLR levels were associated with therapeutic efficacy and prognosis. The patients who remained in or switched to the low NLR level subgroup subsequent to first-line chemotherapy had an improved response and improved OS ratios, compared to the patients remaining in or switching to the high NLR level group. Similar results were observed when the PLR level was investigated. In conclusion, baseline NLR and PLR measurements, as well as changes of NLR and PLR following chemotherapy can predict the prognostic results in patients with unresectable gastric cancer.

Platelets induce apoptosis via membrane-bound FasL

After tissue injury, both wound sealing and apoptosis contribute to restoration of tissue integrity and functionality. Although the role of platelets (PLTs) for wound closure and induction of regenerative processes is well established, the knowledge about their contribution to apoptosis is incomplete. Here, we show that PLTs present the death receptor Fas ligand (FasL) on their surface after activation. Activated PLTs as well as the isolated membrane fraction of activated PLTs but not of resting PLTs induced apoptosis in a dose-dependent manner in primary murine neuronal cells, human neuroblastoma cells, and mouse embryonic fibroblasts. Membrane protein from PLTs lacking membrane-bound FasL (FasL(△m/△m)) failed to induce apoptosis. Bax/Bak-mediated mitochondrial apoptosis signaling in target cells was not required for PLT-induced cell death, but increased the apoptotic response to PLT-induced Fas signaling. In vivo, PLT depletion significantly reduced apoptosis in a stroke model and an inflammation-independent model of N-methyl-d-aspartic acid-induced retinal apoptosis. Furthermore, experiments using PLT-specific PF4Cre(+) FasL(fl/fl) mice demonstrated a role of PLT-derived FasL for tissue apoptosis. Because apoptosis secondary to injury prevents inflammation, our findings describe a novel mechanism on how PLTs contribute to tissue homeostasis.

Leukocyte presence does not increase microbicidal activity of Platelet-rich Plasma in vitro

Background

Human platelets are a rich reservoir of molecules that promote regenerative processes and microbicidal activity. This activity might be increased by concentration in platelet-rich plasma (PRP) products and modulated by the presence of leukocytes. Despite extensive use in clinical procedures, only few studies have investigated PRP’s real microbicidal potential. Therefore, this study aimed at comparing the in vitro microbicidal activity of platelets and leukocyte-enriched PRP (L-PRP) to pure platelet-rich plasma (P-PRP) and the contribution of leukocytes to microbicidal properties.

Antimicrobial effects of P- and L-PRP were tested against Escherichia Coli, Staphylococcus Aureus, Klebsiella Pneumoniae, Pseudomonas Aeruginosa and Enterococcus Faecalis. Furthermore, L-PRP was frozen (L-PRP cryo) to assess whether the preparation maintained in vitro characteristics. Microbicidal proteins released by the three preparations were also evaluated.

Results

L-PRP, L-PRP cryo and P-PRP generally induced comparable bacterial growth inhibition for up to 4 h’ incubation, range 1–4 log. MIP-1α, RANTES, GRO-α, IL-8, NAP-2, SDF-1α and IL-6 showed strong microbicidal potential.

Conclusions

We found in vitro antibacterial activity of L-PRP and P-PRP and the possibility to cryopreserve L-PRP, without important changes to its effectiveness; similar microbicidal activity between preparations containing or not leukocytes; and the contribution of three new molecules (NAP-2, SDF-1α and IL-6).

Tartrate-Resistant Acid Phosphatase 5b in Young Patients With Sickle Cell Disease and Trait Siblings: Relation to Vasculopathy and Bone Mineral Density

Bone involvement is a frequent cause of acute morbidity in sickle cell disease (SCD). Tartrate-resistant acid phosphatase 5b (TRACP 5b), a bone resorption marker, is produced specifically by activated osteoclasts. We assessed bone mineral density (BMD) in 30 young patients with SCD and 17 asymptomatic patients with sickle cell trait (SCT) compared with 32 healthy controls and determined TRACP 5b levels in relation to vascular complications. Serum ferritin, alkaline phosphatase (ALP), and TRACP 5b were measured. Echocardiography was performed with assessment of BMD using dual energy X-ray absorptiometry (DXA). The BMD was decreased in patients with SCD compared with SCT and controls (P = .005), with no significant difference between the latter 2 groups. Patients with SCD had higher incidence of bone complications than SCT group and controls (P = .03). The SCD group with abnormal DXA scan had higher ferritin and ALP than normal BMD. Serum TRACP 5b was significantly higher in patients with SCD than SCT and controls (P = .003). The TRACP 5b levels were associated with severe vaso-occlusive crisis (P = .022). Patients treated with hydroxyurea and those on chelation therapy had lower TRACP 5b levels than untreated patients. The TRACP 5b level was positively correlated with lactate dehydrogenase, while there was no relation with ferritin, ALP, or BMD. We suggest that bone complications frequently occur in SCD as reflected by low BMD and high ALP and TRACP 5b. Hemolysis and iron overload may be involved in the occurrence of these complications. The lack of correlation between abnormal DXA scan and high TRACP 5b suggests that bone disease in SCD is multifactorial.

Preoperative platelet to lymphocyte ratio predicts outcome of patients with pancreatic ductal adenocarcinoma after pancreatic resection

BACKGROUND

Inflammation plays a crucial role in tumor growth, metastasis, and survival. The preoperative platelet-to-lymphocyte ratio (PLR) has been reported as a significant prognostic indicators in several digestive malignancies. Our objective was to evaluate whether preoperative PLR is a prognostic index in resected pancreatic ductal adenocarcinoma.

METHODS

Data from 131 patients who underwent pancreatic resection for pancreatic ductal adenocarcinoma were available from a prospectively maintained database. The patients were divided into groups according to a preoperative PLR of <150 or ≥150. Survival data were analyzed.

RESULTS

In univariate and multivariate analyses, a preoperative PLR of ≥150 was a significant and independent risk factor for cancer recurrence and poor survival, respectively (disease-free survival [DFS]; P= .0014, P = .047; OS, P ≤ .01each). Similarly, lymph node metastasis, and moderate or poor differentiation were independent risk factors for cancer recurrence, whereas tumor diameter, positive surgical margin, and moderate or poor differentiation were independent risk factors for poor patient survival (P ≤ .05 each).

CONCLUSION

The preoperative PLR in patients with pancreatic ductal adenocarcinoma was an independent predictor in DFS and overall survival after elective resection. Measurement of the PLR may help decision making in the postoperative management of patients with pancreatic ductal adenocarcinoma.

Retrospective and comparative study of inflammatory myofibroblastic tumor of the liver

BACKGROUND AND AIM

Inflammatory myofibroblastic tumor of the liver (IMTL) is a very rare benign disease with a good prognosis. The study aims to determine the clinical, radiological, and pathological characteristics of IMTL. The diagnosis and treatment strategies were discussed.

METHODS

A total of 11 patients with pathologically confirmed IMTL receiving treatment over a 15-year period were reviewed retrospectively. The analysis included demographics information and pertinent clinical data. Results obtained from patients with hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (IHCC), and metastatic liver cancer (MLC) receiving surgical resection were compared.

RESULTS

In comparison to HCC, IHCC, and MLC, IMTL has an earlier onset (P < 0.001). IMTL patients had significantly lower aspartate aminotransferase (P = 0.003) and higher alkaline phosphatase (P = 0.034) than HCC patients, and higher gamma-glutamyl transpeptidase (P = 0.010) than MLC patients. Increased serum α-fetoprotein level was detected in only one patient. Serum α-fetoprotein was significantly lower in patients with IMTL (P = 0.000) than in those with HCC but not IHCC (P = 0.558) or MLC (P = 0.514). In contrast to elevated serum CA19-9 in patients with HCC/IHCC/MLC, the serum CA19-9 in IMTL cases was generally normal (vs HCC P = 0.008; vs IHCC P = 0.000; vs MLC P = 0.022). In nine IMTL patients, the tumor appeared as a hypoechogenic solid mass on the ultrasonography. In contrast, most patients with HCC, IHCC, or MLC showed hybrid echo. In contrast computed tomography and magnetic resonance imaging, the lesion of IMTL and MLC appeared as peripheral enhancement.

CONCLUSION

Lab tests, imaging features, and patient history are helpful in the differential diagnosis of IMTL from HCC/IHCC/MLC. Surgical resection is curative for IMTL.

Prognostic value of systemic inflammation-based markers in advanced pancreatic cancer

BACKGROUND

The prognostic significance of various systemic inflammation-based markers has been explored in different cancers. These markers can be used to assist with decision-making in oncology clinics.

AIM

The aim of this study was to investigate the prognostic significance of three systemic inflammation-based factors: neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR) and modified Glasgow Prognostic Score (mGPS) in patients with advanced pancreatic cancer.

METHODS

Data were collected retrospectively for advanced pancreatic cancer patients treated between 1 January 2008 and 31 December 2012 at the Royal Perth Hospital. The ratios were dichotomised as <5 versus ≥5 for NLR and <200 versus ≥200 for PLR. Modified Glasgow Prognostic Scores were scored as: mGPS '0' = both C-reactive protein (CRP) and albumin normal, mGPS '1' = elevated CRP < 10 mg/L and mGPS '2' = both elevated CRP > 10 mg/L and albumin < 35 g/L. Univariate and multivariate analyses were carried out.

RESULTS

Data were evaluable for 124 patients. Median survivals based on the three inflammation-based prognostic markers evaluated were: NLR <5 versus ≥5 = 8.5 months versus 2.6 months respectively (P = 0.0007; hazard ratio (HR) 1.81), PLR <200 versus ≥200 = 9.1 months versus 4 months respectively (P = 0.007; HR 1.64) and mGPS score 1, 2, 3 = 8.3 months, 9.6 months and 1.8 months respectively (P = 0.0004). Besides Eastern Cooperative Oncology Group performance status, NLR, PLR and mGPS were significant independent prognostic markers both on univariate as well as multivariate analysis.

CONCLUSIONS

Our findings suggest that the NLR, PLR and mGPS derived from routine blood tests can be used as clinically meaningful biomarkers to stratify advanced pancreatic cancer patients into different prognostic groups.

Platelet to lymphocyte ratio and neutrophil to lymphocyte ratio in patients with rheumatoid arthritis

OBJECTIVES

It has been well documented that the platelet to lymphocyte ratio (PLR) and the neutrophil to lymphocyte ratio (NLR) are associated with outcomes for patients with gastric cancer, non-small cell lung cancer and acute heart failure. Inflammation may be the hidden factor that explains the correlation between NLP, PLR, and these diseases. However, to date, the data concerning NLR, PLR, and its association with inflammation are lacking in patients with rheumatoid arthritis (RA), thus, our aim to discuss whether NLR and PLR are associated with RA.

METHODS

Patients with RA and healthy individuals were included according to the determined criteria, and laboratory indicators were measured.

RESULTS

PLR and NLR were significantly higher in RA patients compared with healthy controls (3.20±2.06 vs. 1.56±0.47, P<0.01; 192.85±101.78 vs. 103.49±28.68, P<0.01). When leukocytes, neutrophil percentage, neutrophil, lymphocyte, platelet, C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and rheumatoid factor (RF) were considered as confounders (crude model), our results indicated that ESR and RF were correlated to RA. Of note, ESR, RF, and PLR were associated with RA after further adjustment based on crude model for PLR and NLR. Receiver operating characteristic (ROC) curves analysis showed that PLR values higher than >115.7 evaluated RA with a sensitivity of 82.5%, a specificity of 74.8% and area under the curve ( AUC ) of 0.847.

CONCLUSIONS

Our results suggest that PLR is associated with RA, and PLR may be an underlying indicator indicating the chronic subclinical inflammation in patients with RA.

Prognostic significance of neutrophil-to- lymphocyte ratio in esophageal cancer: a meta-analysis

BACKGROUND

The neutrophil-to-lymphocyte ratio (NLR) is a useful predictive factor in several cancers. However, the prognostic value of NLR in patients with esophageal cancer (EC) is still controversial. Therefore, it was necessary for us to perform a meta-analysis to evaluate the prognostic value of NLR in patients with EC.

METHODS

A systematic literature search was performed by using Web of Science, PubMed Central, and Medline to evaluate the prognostic value of NLR in patients with EC. The deadline of our primary search was July 10, 2014. This meta-analysis was conducted in accordance with PRISMA guidelines. Pooled hazard ratio (HR) with 95% confidence interval (CI) was used to assess the association of NLR and overall survival (OS) and disease-free survival (DFS).

RESULTS

Six studies involving 1,633 patients were included in our meta-analysis. Our pooled results demonstrated that high NLR was associated with poor OS (HR: 1.54, 95% CI: 1.32-1.80, I2=25.3%, P=0.254) and DFS (HR: 1.74, 95% CI: 1.25-2.43, I2=63.9%, P=0.096). Subgroup analysis between NLR and OS was performed in a further investigation. When the patients were segregated according to country, sample size, and pathological type, high NLR was also significantly correlated with OS.

CONCLUSION

High NLR is associated with poor prognosis in patients with EC. NLR may be a significant predictive biomarker in patients with EC.

Neutrophil-lymphocyte and platelet-lymphocyte ratio in patients after resection for hepato-pancreatico-biliary malignancies

BACKGROUND AND OBJECTIVES

We sought to determine whether Neutrophil-lymphocyte ratio (NLR) or platelet-lymphocyte ratio (PLR) were associated with outcomes of patients undergoing surgery for a hepatopancreatico-biliary (HPB) malignancy.

METHOD

Between 2000 and 2013, 452 patients who underwent an HPB procedure for a malignant indication were identified. Clinicopathological characteristics, NLR, and PLR, as well as short- and long-term outcomes were analyzed. High NLR and PLR were classified using a cut-off value of 5 and 190, respectively, based on ROC curve analysis.

RESULTS

Patients with low versus high NLR and PLR had similar baseline characteristics with regard to performance status and tumor stage (all P > 0.05). Elevated PLR (HR = 1.40) tends to be association with shorter recurrence-free survival (RFS) (P = 0.05), whereas NLR was not a predictor of shorter RFS. Differently, both elevated NLR (HR = 1.94) and PLR (HR = 1.79) were associated with worse overall survival (OS) (both P < 0.05). Patients with NLR ≥5 and those with PLR ≥190 had a significantly shorter OS compared to patients with NLR <5 and PLR <190, respectively (log-rank test, both P < 0.05). Moreover, patients who had both NLR and PLR elevated had worse OS compared to patients with either one or none inflammatory markers elevated (log-rank P = 0.02).

CONCLUSION

Elevated NLR and PLR were predictors of worse long-term outcome among patients with HPB malignancy undergoing resection.

Platelet function parameters in management of hepatic hydatid disease: a case-controlled study

AIM

To evaluate platelet function in patients with a history of surgical treatment for hepatic hydatid disease (HD).

METHODS

This retrospective case-controlled study was performed in a state hospital in Turkey from January 2009 to November 2013. The patients were divided into two groups: those evaluated in the preoperative period (Group 1) and those evaluated in the postoperative period (Group 2). The patient groups were compared with a control group (Group 3). All three groups were evaluated using laboratory records from day 1 of the preoperative period and day 30 of the postoperative period. The haematocrit level (HTC), platelet count (PLT), mean platelet volume (MPV), platelet distribution width (PDW), and percentage of eosinophils (EOS) were compared among the groups.

RESULTS

Fifty-three patients who had undergone surgical treatment of hepatic HD and 55 healthy controls were included in the study. The mean follow-up time for all patients was 45 (14-70) months. The patients comprised 33 (62%) females and 20 (38%) males. The control group comprised 37 (67%) females and 18 (33%) males. The median age of the patients was 48 (19-78) years, while that of the control group was 42 (16-64) years. No significant differences in the HTC, PLT, or EOS were present among the groups. The MPV and PDW indicated that platelet function was significantly different between Group 1 and Groups 2 and 3. Additionally, nine patients had undergone previous surgical treatment for HD. In a separate long-term follow-up, these patients exhibited no statistically significant differences in MPV or PDW between the preoperative and postoperative periods.

CONCLUSIONS

MPV and PDW can be used in the initial follow-up of patients with hepatic HD, but have limited use in long-term follow-up.

Evaluation of the platelet-to-lymphocyte ratio as a prognostic indicator in a European cohort of patients with prostate cancer treated with radiotherapy

OBJECTIVES

Recent evidence suggests that the presence of a systemic inflammatory response plays an important role in the progression of several solid tumors. The platelet-to-lymphocyte ratio (PLR) has been proposed as an easily assessable marker of systemic inflammation and has been shown to represent a prognostic marker in different cancer entities. To evaluate the prognostic value of the PLR in prostate cancer, we performed the present study.

METHODS AND MATERIALS

Data from 374 consecutive patients with prostate cancer, treated with 3D conformal radiotherapy from 1999 to 2007, were analyzed. Distant metastases-free survival (MFS), cancer-specific survival (CSS), overall survival (OS), biochemical disease-free survival, and time to salvage systemic therapy were assessed using the Kaplan-Meier method. Cox proportional hazards analysis was performed to calculate hazard ratio (HR) and 95% CI. Multivariate Cox regression analysis was performed to adjust for other covariates.

RESULTS

Using receiver operating characteristics analysis, the optimal cutoff level for the PLR was 190. Kaplan-Meier analyses revealed that PLR≥190 was a prognostic factor for decreased MFS (P = 0.004), CSS (P = 0.004), and OS (P = 0.024) whereas a significant association of an elevated PLR with biochemical disease-free survival (P = 0.740) and time to salvage systemic therapy (P = 0.063) was not detected. In multivariate analysis, an increased PLR remained a significant prognostic factor for poor MFS (HR = 2.24, 95% CI: 1.06-4.76, P = 0.036), CSS (HR = 3.99, 95% CI: 1.19-13.4, P = 0.025), and OS (HR = 1.87, 95% CI: 1.02-3.42, P = 0.044).

CONCLUSIONS

Our findings indicate that the PLR may predict prognosis in patients with prostate cancer and may contribute to future individual risk assessment in them.

Prognostic significance of neutrophil to lymphocyte ratio in pancreatic cancer: A meta-analysis

AIM: To conduct a meta-analysis evaluating the association between the peripheral blood neutrophil to lymphocyte ratio (NLR) and the outcome of patients with pancreatic cancer.

METHODS: Studies evaluating the relationship between the peripheral blood NLR and outcome of patients with pancreatic cancer published up to May 2014 were searched using electronic databases, including PubMed, Web of Science, Embase and Ovid. A meta-analysis was performed to pool the hazard ratios (HRs) or odds ratios (ORs) and their 95% confidence intervals (CIs) using either a fixed-effects model or a random-effects model to quantitatively assess the prognostic value of NLR and its association with clinicopathological parameters.

RESULTS: Eleven studies containing a total of 1804 patients were eligible according to our selection criteria, and combined hazard ratios indicated that high NLR was a poor prognostic marker for pancreatic cancer patients because it had an unfavorable impact on the overall survival (OS) (HR = 2.61, 95%CI: 1.68-4.06, P = 0.000) and cancer specific survival (HR = 1.66, 95%CI: 1.08-2.57, P = 0.021). Subgroup analysis revealed that high NLR was associated with poor OS in patients with mixed treatment (HR = 4.36, 95%CI: 2.50-7.61, P = 0.000), chemotherapy (HR = 2.08, 95%CI: 1.49-2.9, P = 0.000), or surgical resection (HR = 1.2, 95%CI: 1.00-1.44, P = 0.048). Additionally, high NLR was significantly correlated with tumor metastasis (OR = 1.69, 95%CI: 1.10-2.59, P = 0.016), poor tumor differentiation (OR = 2.75, 95%CI: 1.19-6.36, P = 0.016), poor performance status (OR = 2.56, 95%CI: 1.63-4.03, P = 0.000), high cancer antigen 199 (OR = 2.62, 95%CI: 1.49-4.60, P = 0.000), high C-reactive protein (OR = 4.32, 95%CI: 2.71-6.87, P = 0.000), and low albumin (OR = 3.56, 95%CI: 1.37-9.27, P = 0.009).

CONCLUSION: High peripheral blood NLR suggested a poor prognosis for patients with pancreatic cancer, and it could be a novel marker of survival evaluation and could help clinicians develop therapeutic strategies for pancreatic cancer patients.

The Inflammatory Role of Platelets via Their TLRs and Siglec Receptors

Platelets are non-nucleated cells that play central roles in the processes of hemostasis, innate immunity, and inflammation; however, several reports show that these distinct functions are more closely linked than initially thought. Platelets express numerous receptors and contain hundreds of secretory products. These receptors and secretory products are instrumental to the platelet functional responses. The capacity of platelets to secrete copious amounts of cytokines, chemokines, and related molecules appears intimately related to the role of the platelet in inflammation. Platelets exhibit non-self-infectious danger detection molecules on their surfaces, including those belonging to the "toll-like receptor" family, as well as pathogen sensors of other natures (Ig- or complement receptors, etc.). These receptors permit platelets to both bind infectious agents and deliver differential signals leading to the secretion of cytokines/chemokines, under the control of specific intracellular regulatory pathways. In contrast, dysfunctional receptors or dysregulation of the intracellular pathway may increase the susceptibility to pathological inflammation. Physiological vs. pathological inflammation is tightly controlled by the sensors of danger expressed in resting, as well as in activated, platelets. These sensors, referred to as pathogen recognition receptors, primarily sense danger signals termed pathogen associated molecular patterns. As platelets are found in inflamed tissues and are involved in auto-immune disorders, it is possible that they can also be stimulated by internal pathogens. In such cases, platelets can also sense danger signals using damage associated molecular patterns (DAMPs). Some of the most significant DAMP family members are the alarmins, to which the Siglec family of molecules belongs. This review examines the role of platelets in anti-infection immunity via their TLRs and Siglec receptors.

New frontiers for platelet CD154

The role of platelets extends beyond hemostasis. The pivotal role of platelets in inflammation has shed new light on the natural history of conditions associated with acute or chronic inflammation. Beyond the preservation of vascular integrity, platelets are essential to tissue homeostasis and platelet-derived products are already used in the clinics. Unanticipated was the role of platelets in the adaptative immune response, allowing a renewed conceptual approach of auto-immune diseases. Platelets are also important players in cancer growth and dissemination. Platelets fulfill most of their functions through the expression of still incompletely characterized membrane-bound or soluble mediators. Among them, CD154 holds a peculiar position, as platelets represent a major source of CD154 and as CD154 contributes to most of these new platelet attributes. Here, we provide an overview of some of the new frontiers that the study of platelet CD154 is opening, in inflammation, tissue homeostasis, immune response, hematopoiesis and cancer.

CD235a (Glycophorin-A) Is the Most Predictive Value Among Different Circulating Cellular Microparticles in Thrombocytopenic Human Immunodeficiency Virus Type 1

BACKGROUND

This study was conducted to assess different cellular microparticles (MPs) in thrombocytopenic human immunodeficiency virus type 1 and their significance as disease activity markers.

METHODS

Thirty-five thrombocytopenic human immunodeficiency diseases and 25 healthy controls with matched age and sex were selected. Viral load was quantitated by COBAS real-time polymerase reaction (PCR) assessment of absolute T-cell subsets CD4, CD8 as a disease progress marker. Platelet MPs, platelet-derived monocyte MPs (CD42a, CD61), erythrocyte MP (CD235a), monocytic MP (CD14), and platelet activity MPs (CD62P, PAC-1) were assessed by multicolor flow cytometry FACSCalibur, while platelet functions were assessed by platelet function analyzer (PFA-100). CD42a, CD61, and platelet activity index represented by PAC-1 and CD62.

RESULTS

P-selectin in HIV-infected patient samples were significantly greater (P < 0.001) than among controls. There was a negative correlation between the proportion of PAC-1 and CD62 P-selectin-positive MPs and levels of CD4(+) T-cell counts (r = -0.403, P = 0.016; r = -0.438, P = 0.008), respectively. There was a negative correlation between collagen-ADP and levels of CD4(+) T-cell counts (r = -0.368, P = 0.03). There was a significant high expression level of CD14 monocyte MPs in patients than controls (P < 0.0001), overexpression of CD235a (P < 0.0001), and no correlation between CD14 and CD4, whereas there was a significant negative correlation with CD235a (r = -0.394, P = 0.019). A linear regression analysis of CD4 as a disease progression marker with other variable indicators in HIV patients showed that CD235a could be the most sensitive predictor similar to CD4.

CONCLUSION

Different cellular MPs and platelets activated in HIV patients could have a role in thrombotic events in these patients.

Are Platelets Cells? And if Yes, are They Immune Cells?

Small fragments circulating in the blood were formally identified by the end of the nineteenth century, and it was suggested that they assisted coagulation via interactions with vessel endothelia. Wright, at the beginning of the twentieth century, identified their bone-marrow origin. For long, platelets have been considered sticky assistants of hemostasis and pollutants of blood or tissue samples; they were just cell fragments. As such, however, they were acknowledged as immunizing (to specific HPA and HLA markers): the platelet’s dark face. The enlightened face showed that besides hemostasis, platelets contained factors involved in healing. As early as 1930s, platelets entered the arsenal of medicines were transfused, and were soon manipulated to become a kind of glue to repair damaged tissues. Some gladly categorized platelets as cells but they were certainly not fully licensed as such for cell physiologists. Actually, platelets possess almost every characteristic of cells, apart from being capable of organizing their genes: they have neither a nucleus nor genes. This view prevailed until it became evident that platelets play a role in homeostasis and interact with cells other than with vascular endothelial cells; then began the era of physiological and also pathological inflammation. Platelets have now entered the field of immunity as inflammatory cells. Does assistance to immune cells itself suffice to license a cell as an “immune cell”? Platelets prove capable of sensing different types of signals and organizing an appropriate response. Many cells can do that. However, platelets can use a complete signalosome (apart from the last transcription step, though it is likely that this step can be circumvented by retrotranscribing RNA messages). The question has also arisen as to whether platelets can present antigen via their abundantly expressed MHC class I molecules. In combination, these properties argue in favor of allowing platelets the title of immune cells.

Differential gene expression in Aspergillus fumigatus induced by human platelets in vitro

Invasive aspergillosis is characterized by vascular invasion and thrombosis. In order to determine the antifungal activity of human platelets, hyphal elongation and metabolic activity of a clinical A. fumigatus isolate were measured. Genome-wide identification of differentially expressed genes in A. fumigatus was performed after exposure to platelets for 15, 30, 60 and 180 min. Data were analyzed by gene ontology annotation as well as functional categories (FunCat) and KEGG enrichment analyses.

Platelets attenuated hyphal elongation and viability of A. fumigatus and in total 584 differentially expressed genes were identified, many of which were associated with regulation of biological processes, stress response, transport and metabolism. FunCat and KEGG enrichment analyses showed stress response and metabolic adaptation to be increased in response to platelets. Our findings demonstrate that A. fumigatus displayed a specific transcriptional response when exposed to platelets, thus reflecting their antifungal activities.

Chronic hepatitis B: role of anti-platelet therapy in inflammation control

Platelets play a known role in the maintenance of vascular homeostasis, but these cells are emerging as important cellular mediators of acute and chronic inflammatory diseases. Platelets are key elements in the pathogenesis of acute and chronic liver disease associated with hepatitis B virus (HBV) infection by promoting the accumulation of virus-specific CD8(+) T cells and nonspecific inflammatory cells into the liver parenchyma. This review discusses major platelet functions in immune and inflammatory responses, with an emphasis on recent pre-clinical studies that suggest that the inhibition of platelet activation pathways represent an alternative therapeutic strategy with potential use in the reduction of virus-specific T cell-mediated chronic inflammation, liver fibrosis and hepatocellular carcinoma in patients who are chronically infected with HBV.

Platelet/lymphocyte ratio was associated with impaired myocardial perfusion and both in-hospital and long-term adverse outcome in patients with ST-segment elevation acute myocardial infarction undergoing primary coronary intervention

Introduction

Platelet/lymphocyte ratio (PLR) has been shown to be an inflammatory and thrombotic biomarker for coronary heart disease, but its prognostic value in ST-segment elevation myocardial infarction (STEMI) has not been fully investigated.

Aim

To investigate the relationship between PLR and no-reflow, along with the in-hospital and long-term outcomes in patients with STEMI.

Material and methods

In the present study, we included 304 consecutive patients suffering from STEMI who underwent primary percutaneous coronary intervention (p-PCI). Patients were stratified according to PLR tertiles based on the blood samples obtained in the emergency room upon admission. No-reflow after p-PCI was defined as a coronary thrombolysis in myocardial infarction (TIMI) flow grade ≤ 2 after vessel recanalization, or TIMI flow grade 3 together with a final myocardial blush grade (MBG) < 2.

Results

The mean follow-up period was 24 months (range: 22–26 months). The number of patients characterized with no-reflow was counted to depict increments throughout successive PLR tertiles (14% vs. 20% vs. 45%, p < 0.001). In-hospital major adverse cardiovascular events and death increased as the PLR increased (p < 0.001, p < 0.001). Long-term MACE and death also increased as the PLR increased (p < 0.001, p < 0.001). Multivariable logistic regression analysis revealed that PLR remained an independent predictor for both in-hospital (OR = 1.01, 95% CI: 1.00–1.01; p = 0.002) and major long-term (OR = 1.01, 95% CI: 1.00–1.01; p < 0.001) adverse cardiac events.

Conclusions

Platelet/lymphocyte ratio on admission is a strong and independent predictor of both the no-reflow phenomenon and long-term prognosis following p-PCI in patients with STEMI.

Relationship between prognosis and neutrophil: lymphocyte and platelet:lymphocyte ratios in patients with malignant pleural mesotheliomas

BACKGROUND

It has been demonstrated that neutrophil:lymphocyte (NLR) and platelet:lymphocyte (PLR) ratios are associated with prognosis in cancer patients. The aim of this study was to investigate whether pretreatment white blood cell (WBC), neutrophil, lymphocyte, monocyte, platelet, basophil and eosinophil counts, LDH level, NLR and PLR are associated with prognosis in patients with malignant pleural mesothelioma (MPM).

MATERIALS AND METHODS

We retrospectively reviewed files of 50 patients who were managed with a diagnosis of MPM between 2005 and 2010. Demographic and clinical characteristics, treatments, response to treatment and prognostic factors were evaluated, along with relationships between pretreatment blood parameters and prognosis.

RESULTS

Overall, 38 men and 12 women were included to the study. Mean age was 61.5±9.4 years (range: 39-83 years). There was advanced disease in 86% (n=43) and the histological type was epithelial mesothelioma in the majority (82%). Of the cases, 17 (34%) received radiotherapy, while 42 cases underwent first- and second-line chemotherapy, with cisplatin plus pemetrexed as the most commonly used regimen. In the assessment after therapy, it was found that there was complete response in 4 cases (8%), partial response in 10 cases (20%), stable disease in 17 cases (34%) and progression in 19 cases (38%). Median follow-up was 10 months (range: 10 day-30 months). Median overall survival was found to be 20.7 months while median progression-free survival as 10 months. In univariate and multivariate analyses, it was found that factors significantly affecting overall survival included stage (p=0.030), response to treatment (p=0.026) and monocyte count (p=0.004), while factors affecting disease-free survival included NLR (p=0.018), response to treatment (p=0.001), and PLR score (p=0.003).

CONCLUSIONS

Overall and disease-free survival was found to be better in cases with a WBC count<8.000, platelet count<300,000, and low NLR and PLR scores in malignant pleural mesothelioma.

A prognostic model based on pretreatment platelet lymphocyte ratio for stage IE/IIE upper aerodigestive tract extranodal NK/T cell lymphoma, nasal type

Patients with stage IE/IIE natural killer T (NK/T) cell lymphomas have discrepant survival outcome. This study aims to establish a prognostic model based on the pretreatment platelet lymphocyte ratio (PLR) specifically for localized extranodal NK/T cell lymphoma to guide the therapy. We retrospectively analyzed the data of 252 patients with early-stage upper aerodigestive tract NK/T cell lymphoma. The 5-year overall survival rate in 252 patients was 67.1%. Prognostic factors for survival were female (P = 0.025; relative risk, 0.51; 95% CI 0.28-0.92), older age (P = 0.000; relative risk, 3.34; 95% CI 1.94-5.75), stage II(P = 0.020; relative risk, 1.79; 95% CI 1.10-2.91), lactate dehydrogenase (LDH) level (P = 0.009; relative risk, 2.00; 95% CI 1.19-3.35), and PLR (P = 0.020; relative risk, 1.77; 95% CI 1.10-2.87). Based on these five parameters, we identified three different risk groups: group 1(106 cases, 43.4%), no or one adverse factor; group 2(85 cases, 34.8%), two factors; group 3(53 cases, 21.7%), three to five factors. Five-year overall survival was 83.3% for group 1, 62.2% for group 2, and 43.1% for group 3 (P = 0.000). Compared with International Prognostic Index and Korean Prognostic Index, the new model has a better prognostic discrimination for the patients of stage IE/IIE upper aerodigestive tract NK/T cell lymphoma. The PLR-based prognosis model is useful to stratify patients with localized extranodal NK/T cell lymphoma into different risk groups and guide the treatment modalities selection.

Preoperative neutrophil-lymphocyte ratio before platelet-lymphocyte ratio predicts clinical outcome in patients with cervical cancer treated with initial radical surgery

OBJECTIVE

Several inflammatory parameters are applied to predict the survival of patients with various cancers. Neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR) are 2 nonspecific markers of systemic inflammation. This study aimed to evaluate the clinicopathologic and prognostic values of NLR and PLR in patients with cervical cancer undergoing primary radical hysterectomy with pelvic lymphadenectomy.

METHODS

A total of 460 cervical cancer patients were enrolled in this study. These patients were histologically confirmed with cervical cancer from February 2005 to June 2008, at the Department of Gynecology, the Third Affiliated Hospital of Harbin Medical University, China. Their clinical and histopathological markers and complete blood counts were collected and analyzed. Prognostic factors were assessed by univariate and multivariate analyses.

RESULTS

The median NLR and PLR were 2.213 and 150.9, respectively. The clinicopathologic analysis showed that NLR was highly associated with depth of stromal infiltration (P = 0.007) and lymph node metastasis (P = 0.003), and PLR was significantly related to tumor size (P = 0.020) and lymph node metastasis (P = 0.027).Univariate analysis identified high NLR as a statistically significant poor predictive factor for the progression-free survival (PFS) (P = 0.008) and overall survival (OS) (P = 0.014), and PLR exhibited no significance on PFS (P = 0.075) and OS (P = 0.110).Multivariable analysis showed that the NLR was an independent prognostic marker for PFS (hazard ratio, 1.799; 95% confidence interval, 1.069-3.028; P = 0.027), but not for OS (hazard ratio, 1.631; 95% confidence interval, 0.968-2.750; P = 0.066).

CONCLUSIONS

Preoperative NLR and PLR were found to be correlated to unfavorable histopathologic features of cervical cancer. The preoperative NLR, but not PLR, may be used as a potential and easy biomarker for survival prognosis in patients with cervical cancer receiving initial radical hysterectomy with pelvic lymphadenectomy.

The independent assocıatıon of plateletcrıt wıth long-term outcomes in patıents undergoıng prımary percutaneous coronary interventıon

PURPOSE

Platelets play a key role in the genesis of thrombosis. Plateletcrit (PCT) provides complete information on total platelet mass. The relationship between PCT values and long-term outcomes in patients with ST-segment elevation myocardial infarction (STEMI) who undergo primary angioplasty is not known. We sought to determine the effect of PCT values on the outcomes of primary angioplasty for STEMI.

METHODS

Overall, 2572 consecutive STEMI patients (mean age, 56.6±11.8 years) undergoing primary percutaneous coronary intervention were enrolled retrospectively into the present study. Plateletcrit at admission was measured as part of the automated complete blood count. Patients were classified into 2 groups: high PCT (>0.237, n=852) and nonhigh PCT (<0.237, n=1720). Clinical characteristics and in-hospital and long-term (median, 21 months) outcomes of primary angioplasty were analyzed.

RESULTS

A higher in-hospital shock rate was observed among patients with high PCT values compared with those with nonhigh PCT values (6.5 vs 3.8%, respectively; P=.003). The long-term cardiovascular prognosis was worse for patients with high PCT values (Kaplan-Meier, log-rank test; P=.007). We used Cox proportional hazard models to examine the association between PCT and adverse clinical outcomes. High PCT values were also an independent predictor of cardiovascular mortality (hazard ratio, 1.85; 95% confidence interval, 1.061-3.22; P=.03).

CONCLUSION

High PCT values on admission are independently associated with long-term adverse outcomes in patients with STEMI who undergo primary angioplasty.

Modulation of P-selection and platelet aggregation in chronic periodontitis: A clinical study

Background:

The primary etiologic factor of periodontitis is the subgingival infection with a group of Gram negative pathogens. Transient bacteremia in periodontitis patients underlie chronic production and systemic increases of various proinflammatory mediators, including Interleukin (IL)-1α, IL-6, C-reactive protein and Tumor necrosis factor (TNF)-α. P- selectin is a member of selectin family of cell surface receptor which is located in the membrane of the secretory granules (alpha granules) of platelets and in the membrane of the Weibel-Palade bodies of the vascular endothelial cells. P selectin redistributes from the membrane of the granules to the plasma membrane when platelets and endothelial cells are activated and thus degranulated.

Aim:

To compare the level of platelet activation, soluble P Selectin level and morphological changes and aggregation of platelets in patients in periodontitis patients compared to healthy controls.

Materials and Methods:

80 patients were included in the study with the age group of 35-60. The patients were divided into 2 groups, 40 subjects with generalized chronic periodontitis and 40 healthy subjects taken as control. Periodontal Examination using clinical parameters namely, Bleeding Index, Plaque Index, Probing Pocket Depth and Clinical Attachment Level were recorded. Collection of blood samples for estimation of serum soluble P- selectin level by ELISA method. Evaluation of Platelet morphology and grading the platelet aggregation.

Results:

P-selectin expression shows that the mean value for control group is 4.97 ± 16.56 ng/mL and study group 13.05 ± 29.94 ng/mL which was significantly higher than control group with P value 0.001. Platelet morphological changes shows small form – mean value for control group is 75.83% ± 14.24% while for study group is 39.08%. ± 21.59; Big form – mean value for control group 0.80% ± 0.35% while for study group 0.48% ± 1.3%and Spider form- mean value for control group 23.88% ± 14.13 while study group 59.32% ±. 23.42. The observation showed high statistical significance with P- value < 0.001 for small and spider form and no statistical significance for big form P = 0.075.

Conclusion:

Increased expression of P-selectin, spider form of platelets and pathological aggregation pattern which indicates that platelet activation may be associated with chronic periodontitis. The results of the study showed, higher number of spider forms and significant pathological aggregation pattern in periodontitis patients which indicates activation of platelets thus emphasized that periodontitis can be an contributing factor in the development of cardiovascular disease.

Prognostic value of PLR in various cancers: a meta-analysis

Background

Recently, more and more studies investigated the association of inflammation parameters such as the Platelet Lymphocyte Ratio (PLR) and the prognosis of various cancers. However, the prognostic role of PLR in cancer remains controversial.

Methods

We conducted a meta-analysis of published studies to evaluate the prognostic value of PLR in various cancers. In order to investigate the association between PLR and overall survival (OS), the hazard ratio (HR) and its 95% confidence interval (CI) were calculated.

Results

A total of 13964 patients from 26 studies were included in the analysis. The summary results showed that elevated PLR was a negative predictor for OS with HR of 1.60 (95%CI: 1.35–1.90; P_{heterogeneity} <0.001). Subgroup analysis revealed that increased PLR was a negative prognostic marker in patients with gastric cancer (HR = 1.35, 95%CI: 0.80–2.25, P_{heterogeneity} = 0.011), colorectal cancer (HR = 1.65, 95%CI: 1.33–2.05, P_{heterogeneity} = 0.995), hepatocellular carcinoma (HR = 3.07, 95% CI: 2.04–4.62, P_{heterogeneity} = 0.133), ovarian cancer (HR = 1.57, 95%CI: 1.07–2.31, P_{heterogeneity} = 0.641) and non-small cell lung cancer (NSCLC) (HR = 1.85, 95% CI: 1.42–2.41, P_{heterogeneity} = 0.451) except for pancreatic cancer (HR = 1.00, 95%CI: 0.92–1.09, P_{heterogeneity} = 0.388).

Conclusion

The meta-analysis demonstrated that PLR could act as a significant biomarker in the prognosis of various cancers.

Neutrophil–Lymphocyte Ratio and Platelet–Lymphocyte Ratio Combination Can Predict Prognosis in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

We assessed the effect of combination of neutrophil–lymphocyte ratio (NLR) and platelet–lymphocyte ratio (PLR) in predicting in-hospital and long-term mortality in patients (n = 2518) undergoing primary percutaneous coronary intervention (pPCI). Cutoff values for NLR and PLR were calculated with receiver–operating characteristic (ROC) curves. If both PLR and NLR were above the threshold, patients were classified as “high risk.” If either PLR or NLR was above the threshold individually, patients were classified as “intermediate risk.” High-risk (n = 693) and intermediate-risk (n = 545) groups had higher in-hospital and long-term mortality (7.2 4% vs 0.7%, P < .001; 14.1, 9.5% vs 4.5%, P < .001, respectively). Classifying patients into intermediate-risk group (hazards ratio [HR]: 1.492, 95% confidence interval [CI]: 1.022-2.178, P = .038) and high-risk group (HR: 1.845, 95% CI: 1.313-2.594, P < .001) was an independent predictor of in-hospital and long-term mortality. The combination of PLR and NLR can be useful for the prediction of in-hospital and long-term mortality in patients undergoing pPCI.

The elevated preoperative platelet-to-lymphocyte ratio predicts poor prognosis in breast cancer patients

BACKGROUND

The elevation of the platelet-to-lymphocyte ratio (PLR), an easily applicable blood test based on platelet and lymphocyte counts has been associated with poor prognosis in patients with different types of cancer. The present study was aimed to investigate the prognostic significance of the preoperative PLR in a large cohort of breast cancer patients.

METHODS

Data from 793 consecutive non-metastatic breast cancer patients, treated between 1999 and 2004, were evaluated retrospectively. The optimal cutoff values for the PLR were calculated using receiver operating curve analysis. Cancer-specific survival (CSS), overall survival (OS) as well as distant metastasis-free survival (DMFS) were assessed using the Kaplan-Meier method. To evaluate the independent prognostic significance of PLR, multivariable Cox regression models were applied for all three different end points.

RESULTS

Univariable analysis revealed a significant association between the elevated preoperative PLR and CSS (hazard ratio (HR): 2.75, 95% confidence interval (CI): 1.57-4.83, P<0.001) that remained statistically significant in multivariable analysis (HR: 2.03, 95% CI: 1.03-4.02, P=0.042). An increased PLR was also significantly associated with decreased OS in univariable (HR: 2.45, 95% CI: 1.43-4.20, P=0.001) and in multivariable analysis (HR: 1.92, 95% CI: 1.01-3.67, P=0.047). Furthermore, univariable analysis showed a significant impact of increased PLR on DMFS (HR: 2.02, 95% CI: 1.18-3.44, P=0.010). Subgroup analysis revealed significant associations of the elevated PLR on the primary end point CSS for all breast cancer subtypes. This association retained its significance in multivariable analysis in patients with luminal B tumours (HR: 2.538, 95% CI: 1.043-6.177, P=0.040).

CONCLUSIONS

In this study, we identified the preoperative PLR as an independent prognostic marker for survival in breast cancer patients. Independent validation of our findings is needed.

A platelet-inspired paradigm for nanomedicine targeted to multiple diseases

Platelets are megakaryocyte-derived anucleated cells found in the blood. They are mainly responsible for rendering hemostasis or clotting to prevent bleeding complications. Decreased platelet numbers or deficiencies in platelet functions can lead to various acute or chronic bleeding conditions and hemorrhage. On the other hand, dysregulated hyperactivity of the clotting process can lead to thrombosis and vascular occlusion. There is significant evidence that beyond hemostasis and thrombosis, platelets play crucial mechanistic roles in other disease scenarios such as inflammation, immune response and cancer metastasis by mediating several cell-cell and cell-matrix interactions, as well as aiding the disease microenvironment via secretion of multiple soluble factors. Therefore, elucidating these mechanistic functions of platelets can provide unique avenues for developing platelet-inspired nanomedicine strategies targeted to these diseases. To this end, the current review provides detailed mechanistic insight into platelets' disease-relevant functions and discusses how these mechanisms can be utilized to engineer targeted nanomedicine systems.

Prognostic role of platelet to lymphocyte ratio in solid tumors: a systematic review and meta-analysis

BACKGROUND

Inflammation influences cancer development and progression. An elevated platelet to lymphocyte ratio (PLR), a marker of inflammation, has been linked to poor prognosis in several malignancies. Here, we quantify the prognostic impact of this biomarker.

METHODS

A systematic review of databases was conducted to identify publications exploring the association of blood PLR and overall survival (OS) in solid tumors. Data were pooled in a meta-analysis. Pooled HRs for OS by disease group and by PLR cutoff groups were computed and weighted using generic inverse-variance and random-effect modeling.

RESULTS

Twenty studies comprising 12,754 patients were assessed. Cutoffs for PLR defining risk groups ranged from 150 to 300 and were dichotomous (12 studies; group 1) or split into three groups (<150/150-300/>300, 8 studies; group 2). Higher PLR was associated with significantly worse OS in group 1 [HR = 1.87; 95% confidence interval (CI, 1.49-2.34); P < 0.001] and with a nonsignificant association in group 2 (HR per higher category = 1.21; 95%CI, 0.97-1.50; P = 0.10). The size of effect of PLR on OS was greater for metastatic disease (HR[group 1] = 2.0; 95% CI, 1.6-2.7; HR[group 2] = 1.6; 95% CI, 1.1-2.4) than for early-stage disease (HR[group 1] = 1.5; 95% CI, 1.0-2.2; HR[group 2] = 1.0; 95% CI, 0.8-1.3). A significant association was observed for colorectal, hepatocellular, gastroesophageal, ovarian, and pancreatic carcinoma in group 1 and for colorectal cancers in group 2.

CONCLUSION

A high PLR is associated with worse OS in various solid tumors. Further research of its regulation and relevance in daily practice is warranted.

IMPACT

PLR is a readily available and inexpensive biomarker with independent prognostic value in solid tumors.

Signal transduction of platelet-induced liver regeneration and decrease of liver fibrosis

Platelets contain three types of granules: alpha granules, dense granules, and lysosomal granules. Each granule contains various growth factors, cytokines, and other physiological substances. Platelets trigger many kinds of biological responses, such as hemostasis, wound healing, and tissue regeneration. This review presents experimental evidence of platelets in accelerating liver regeneration and improving liver fibrosis. The regenerative effect of liver by platelets consists of three mechanisms; i.e., the direct effect on hepatocytes, the cooperative effect with liver sinusoidal endothelial cells, and the collaborative effect with Kupffer cells. Many signal transduction pathways are involved in hepatocyte proliferation. One is activation of Akt and extracellular signal-regulated kinase (ERK)1/2, which are derived from direct stimulation from growth factors in platelets. The other is signal transducer and activator of transcription-3 (STAT3) activation by interleukin (IL)-6 derived from liver sinusoidal endothelial cells and Kupffer cells, which are stimulated by contact with platelets during liver regeneration. Platelets also improve liver fibrosis in rodent models by inactivating hepatic stellate cells to decrease collagen production. The level of intracellular cyclic adenosine monophosphate (cyclic AMP) is increased by adenosine through its receptors on hepatic stellate cells, resulting in inactivation of these cells. Adenosine is produced by the degradation of adenine nucleotides such as adenosine diphosphate (ADP) and adenosine tri-phosphate (ATP), which are stored in abundance within the dense granules of platelets.

Genome-wide association studies for hematological traits in Chinese Sutai pigs

Background

It has been shown that hematological traits are strongly associated with the metabolism and the immune system in domestic pig. However, little is known about the genetic architecture of hematological traits. To identify quantitative trait loci (QTL) controlling hematological traits, we performed single marker Genome-wide association studies (GWAS) and haplotype analysis for 15 hematological traits in 495 Chinese Sutai pigs.

Results

We identified 161 significant SNPs including 44 genome-wide significant SNPs associated with 11 hematological traits by single marker GWAS. Most of them were located on SSC2. Meanwhile, we detected 499 significant SNPs containing 154 genome-wide significant SNPs associated with 9 hematological traits by haplotype analysis. Most of the identified loci were located on SSC7 and SSC9.

Conclusions

We detected 4 SNPs with pleiotropic effects on SSC2 by single marker GWAS and (or) on SSC7 by haplotype analysis. Furthermore, through checking the gene functional annotations, positions and their expression variation, we finally selected 7 genes as potential candidates. Specially, we found that three genes (TRIM58, TRIM26 and TRIM21) of them originated from the same gene family and executed similar function of innate and adaptive immune. The findings will contribute to dissection the immune gene network, further identification of causative mutations underlying the identified QTLs and providing insights into the molecular basis of hematological trait in domestic pig.

Association between parathyroid hormone levels and inflammatory markers among US adults

Background and Aims. High levels of parathyroid hormone (PTH) appear to be associated with an increased mortality. Previous studies concerning the relationship of inflammatory markers with hyperparathyroidism have yielded inconsistent results. This study investigated whether serum PTH concentrations were independently associated with several inflammatory markers among the US adults. Materials and Methods. Using data from the National Health and Nutrition Examination Survey, we examined the relation between serum PTH and C-reactive protein (CRP), red cell distribution width (RDW), and platelet-to-lymphocyte ratio (PLR) levels with weighted linear regression. Additionally, we examined the relation with increased modified Glasgow Prognostic Score (mGPS) by using weighted logistic regression. Results. CRP, RDW, and PLR values increased with increasing serum PTH concentration. After extensively adjusting for covariates, CRP and RDW increased linearly and across PTH categories (all P < 0.001), while PLR marginally increased (P = 0.190 and P = 0.095 using PTH as a categorical and continuous variable, resp.). The odds ratio of increased mGPS was 1.11 and 1.31 across PTH categories and with increasing PTH levels continuously. Conclusion. These nationally representative data indicate that serum PTH levels are independently associated with several inflammatory markers in the US population. The casual relationship between PTH levels and inflammation remains to be elucidated.

Preoperative platelet lymphocyte ratio (PLR) is superior to neutrophil lymphocyte ratio (NLR) as a predictive factor in patients with esophageal squamous cell carcinoma

Background

Recent studies have shown that the presence of systemic inflammation correlates with poor survival in various cancers. The aim of this study was to determinate the prognostic value of the neutrophil lymphocyte ratio (NLR) and the platelet lymphocyte ratio (PLR) in patients with esophageal squamous cell carcinoma (ESCC).

Methods

Preoperative NLR and PLR were evaluated in 483 patients undergoing esophagectomy for ESCC from January 2005 to December 2008. The prognostic significance of both markers was then determined by both uni- and multivariate analytical methods. Receiver operating characteristic (ROC) curves were also plotted to verify the accuracy of NLR and PLR for survival prediction.

Results

High preoperative NLR (≥3.5 versus < 3.5, P = 0.039) and PLR (≥150 versus < 150, P < 0.001) were significantly associated with poor overall survival in multivariate analysis. However, our study demonstrated a better discrimination for the PLR in terms of hazard ratio(HR) than the NLR (HR = 1.840 versus HR = 1.339). Patients with NLR ≥3.5 had significantly poorer overall survival compared to NLR <3.5 (35.4% versus 57.7%, P < 0.001). Patients with PLR ≥150 also had significantly poorer overall survival compared to patients with PLR <150 (32.7% versus 63.5%, P < 0.001). The area under the curve (AUC) was 0.658 (95% confidence interval (CI): 0.610 to 0.706, P < 0.001) for NLR and 0.708 (95% CI: 0.662 to 0.754, P < 0.001) for PLR, indicating that PLR was superior to NLR as a predictive factor in ESCC.

Conclusions

Preoperative NLR and PLR were significant predictors of overall survival in patients with ESCC. However, PLR is superior to NLR as a predictive factor in patients with ESCC.

The elevated preoperative platelet to lymphocyte ratio predicts decreased time to recurrence in colon cancer patients

BACKGROUND

Recent evidence indicates that tumor progression involves factors of systemic inflammation, such as platelets and lymphocytes. In this study, we investigated the prognostic relevance of the preoperative platelet to lymphocyte (P/L) ratio on time to recurrence (TTR) and overall survival (OS) in patients with stage II and III colon cancer (CC) who underwent curative resection.

METHODS

In this retrospective study, 372 CC patients were included. Kaplan-Meier curves and multivariate Cox proportional models were calculated for TTR and OS.

RESULTS

In univariate analysis, the elevated P/L ratio was significantly associated with decreased TTR (HR = 1.60, 95% CI = 1.02 to 2.51, P = .040) and remained significant in multivariate analysis (HR = 1.65, 95% CI = 1.05 to 2.58, P = .030), where HR and CI represent Hazard ratio and confidence interval, respectively. Patients with elevated P/L ratio showed a median TTR of 116 months. In contrast, patients with low P/L ratio had a median TTR of 132 months. In OS analysis, the elevated P/L ratio showed a trend toward decreased OS in univariate analysis (HR = 1.54, 95% CI = .95 to 2.48, P = .079).

CONCLUSION

In this study, we identified the preoperative P/L ratio as a prognostic marker for TTR in stage II and III CC patients.

Interference with the host haemostatic system by schistosomes

Schistosomes, parasitic flatworms that cause the tropical disease schistosomiasis, are still a threat. They are responsible for 200 million infections worldwide and an estimated 280,000 deaths annually in sub-Saharan Africa alone. The adult parasites reside as pairs in the mesenteric or perivesicular veins of their human host, where they can survive for up to 30 years. The parasite is a potential activator of blood coagulation according to Virchow's triad, because it is expected to alter blood flow and endothelial function, leading to hypercoagulability. In contrast, hepatosplenic schistosomiasis patients are in a hypocoagulable and hyperfibrinolytic state, indicating that schistosomes interfere with the haemostatic system of their host. In this review, the interactions of schistosomes with primary haemostasis, secondary haemostasis, fibrinolysis, and the vascular tone will be discussed to provide insight into the reduction in coagulation observed in schistosomiasis patients.

Interference with the haemostatic system by pathogens is a common mechanism and has been described for other parasitic worms, bacteria, and fungi as a mechanism to support survival and spread or enhance virulence. Insight into the mechanisms used by schistosomes to interfere with the haemostatic system will provide important insight into the maintenance of the parasitic life cycle within the host. This knowledge may reveal new potential anti-schistosome drug and vaccine targets. In addition, some of the survival mechanisms employed by schistosomes might be used by other pathogens, and therefore, these mechanisms that interfere with host haemostasis might be a broad target for drug development against blood-dwelling pathogens. Also, schistosome antithrombotic or thrombolytic molecules could form potential new drugs in the treatment of haemostatic disorders.

The comparison of thrombocytosis and platelet-lymphocyte ratio as potential prognostic markers in colorectal cancer

The aim of the present study was to analyse the preoperative platelet count and the platelet-lymphocyte ratio (PLR) in patients with colorectal cancer (CRC) of different stages and with hepatic metastasis of CRC (mCRC) and to compare these factors as potential prognostic markers. Clinicopathological data of 10 years were collected retrospectively from 336 patients with CRC and 118 patients with mCRC. Both in the CRC and the mCRC group overall survival (OS) was significantly worse in patients who had elevated platelet count (hazard ratio [HR] = 2.2, p < 0.001 and HR = 2.9, p = 0.018, respectively). Multivariate analysis indicated that elevated platelet count was an independent prognostic factor of CRC (HR = 1.7, p = 0.035) and mCRC (HR = 3.1, p = 0.017). Disease-free survival (DFS) was significantly worse in patients with elevated platelet count in the CRC group (HR = 2.0, p = 0.011). In the multivariate analysis the PLR was not a prognostic factor in either of the two cohorts (HR = 0.92, p < 0.001 and HR = 0.89, p = 0.789, respectively). The platelet count is a valuable prognostic marker for the survival in patients both with CRC and mCRC while the PLR is not prognostic in either group.

Adenovirus type 3 induces platelet activation in vitro

In the present study, we aimed to investigate platelet activation induced by adenovirus type 3 (HAdV3) in vitro. Platelet-rich plasma (PRP) or whole blood was incubated with or without HAdV at various concentrations. Platelet aggregation, platelet counting, fibrinogen and expression of platelet membrane antigens (CD41a and CD62P) were determined following incubation with HAdV for different periods of time. The results demonstrated that HAdV at the concentrations of 109-1011 vp/ml enhanced adenosine diphosphate (ADP) or ristocetin-induced platelet aggregation, however did not alter the platelet count. Infection with HAdVs also reduced fibrinogen level. P-selectin and CD41a appeared rapidly on the surface after platelets were incubated with HAdVs in vitro for 30 min. In conclusion, HAdVs may induce activation of platelets and lead to a pre-thrombotic state of peripheral blood. This finding may aid in the development of measures to prevent severe HAdV infection.

Combination of neutrophil lymphocyte ratio and platelet lymphocyte ratio is a useful predictor of postoperative survival in patients with esophageal squamous cell carcinoma

Background

Recent studies have shown that the presence of systemic inflammation correlates with poor survival in various types of cancers. This study investigated the usefulness of a novel inflammation-based prognostic system, using the combination of neutrophil lymphocyte ratio (NLR) and platelet lymphocyte ratio (PLR), collectively named the CNP, for predicting survival in patients with esophageal squamous cell carcinoma (ESCC).

Materials and methods

The CNP was calculated on the basis of data obtained on the day of admission: patients with both elevated NLR (>3.45) and PLR (>166.5) were allocated a score of 2, and patients showing one or neither were allocated a score of 1 or 0, respectively.

Results

The CNP was associated with tumor length (P<0.001), differentiation (P=0.021), depth of invasion (P<0.001), and nodal metastasis (P<0.001). No significant differences were found between the CNP and morbidity. However, significant differences were found between the CNP and mortality (P,0.001). The overall survival in the CNP 0, CNP 1, and CNP 2 groups were 63.4%, 50.0%, and 20.2%, respectively (CNP 0 versus CNP 1, P=0.014; CNP 1 versus CNP 2, P<0.001). Multivariate analyses showed that CNP was a significant predictor of overall survival. CNP 1–2 had a hazard ratio (HR) of 1.964 (95% confidence interval [CI]: 1.371–2.814, P<0.001) for overall survival. CNP (HR =1.964, P<0.001) is superior to NLR (HR =1.310, P=0.053) or PLR (HR =1.751, P<0.001) as a predictive factor.

Conclusion

The CNP is considered a useful predictor of postoperative survival in patients with ESCC. The CNP is superior to NLR or PLR as a predictive factor in patients with ESCC.