Platelet size has diagnostic predictive value in patients with thrombocytopenia

Predicting the dynamics of organ failure in patients with acute pancreatitis depending on the mean platelet volume

Background

The aim of this study is to determine the correlation between the blood serum mean platelet volume (MPV) and the dynamics of the OF course during the early phase in patients with moderately severe and severe acute pancreatitis (AP).

Methods

The predetermined criterion was the presence of the OF according to the revised Atlanta criteria 2012 for moderately severe and severe AP. A prospective sample of patients was stratified by severity, and two groups were defined based on MPV. Demographic indicators, comorbidities and clinical outcomes were compared between these groups. Multifactorial analysis determined whether an elevated MPV is independently associated with early OF and other unfavorable outcomes.

Results

Out of 108 patients, 20 had moderately severe AP and 88 had severe AP. The blood serum MPV, measured within 72 h of the onset of AP symptoms was lower 11.8 fL in 32 patients and equal to or greater 11.8 fL in 76 patients. Patients with elevated MPV were older (63 vs. 48 years), had obesity (59.2 % vs. 25 %), diabetes mellitus (DM) (51.3 % vs. 12.5 %), ischemic heart disease (70.8 % vs. 28.1 %) and more frequently experienced persistent OF (93.4 % vs. 53.1 %) compared to those with MPV lower 11.8 fL. The incidence of early OF increased proportionally with the severity of MPV (81.6 % vs. 34.4 % in the group with MPV lower 11.8 fL, Ptrend < 0.0001). In multifactorial analysis, adjusted for body mass index and DM, MPV equal to or greater 11.8 fL was independently associated with early OF.

Conclusions

Elevated blood serum MPV of patients with AP are independently and proportionally correlated with early organ failure in patients with alcoholic and idiopathic etiology of AP.

Key message

The study provides an evaluation of MPV as a prognostic marker for organ failure within the initial 7 days following the onset of acute pancreatitis symptoms. Additionally, alterations in MPV were identified in patients with acute pancreatitis who had diabetes or ischemic heart disease within the first 24 h of hospitalization.

Analytical verification of the Dymind D7-CRP automated analyser

Introduction

The aim of this study was to perform a verification of the Dymind D7-CRP automated analyser and compare it with established analysers.

Materials and methods

Analytical verification included estimation of repeatability, between run precision, within-laboratory precision, and bias in control samples with low, normal and high levels. The acceptance criteria for analytical verification were defined using the European Federation of Clinical Chemistry and Laboratory Medicine (EFLM) 2019 Biological Variation Database. Method comparison between the Dymind D7-CRP and the Sysmex XN1000 for haematological parameters and the Dymind D7-CRP and the Beckman Coulter AU680 for CRP values was performed on 40 patient samples.

Results

Analytical verification criteria were adequately met with the exception of monocyte count for repeatability and within-laboratory precision (13.4% and 11.5%, respectively, acceptance criteria 10.1%) and measurement uncertainty (23.0, acceptance criteria 20.0%) at low level, eosinophil count for BIAS at the low level (37.7%, acceptance criteria 25.2%), basophil count (BAS) for BIAS at the high level (14.2%, acceptance criteria 10.9%), and mean platelet volume (MPV) for repeatability (4.2% and 6.8%), between run precision (2.2% and 4.7%), within-laboratory precision (4.0% and 7.3%) (acceptance criteria 1.7%), and measurement uncertainty (8.0 and 14.6%, acceptance criteria 3.4%) at both the low and high concentrations. Method comparison showed no clinically significant constant or proportional differences for all parameters except BAS and MPV.

Conclusion

The analytical verification of the Dymind D7-CRP showed adequate analytical characteristics. The Dymind D7-CRP can be used interchangeably with the Sysmex XN-1000 for all parameters tested, except BAS and MPV, and with the Beckman Coulter AU-680 for the determination of CRP.

Laboratory Markers of Platelet Production and Turnover

Platelets are formed from bone marrow megakaryocytes, circulate in blood for 7-10 days, and then are destroyed in the spleen and/or liver. Platelet production depends on the megakaryocyte population state in the bone marrow: number and size of the cells. The platelet turnover, i.e., the number of platelets passing through the bloodstream in a certain time, is determined by both the rate of their production and the rate of their destruction. The review considers laboratory markers, which are used to assess platelet production and turnover in the patients with hematologic and cardiovascular pathologies. These markers include some characteristics of platelets themselves: (i) content of reticulated ("young") forms in the blood detected by their staining with RNA dyes; (ii) indicators of the platelet size determined in hematology analyzers (mean volume, percentage of large forms) and in flow cytometers (light scattering level). Alterations of platelet production and turnover lead to the changes in blood plasma concentrations of such molecules as thrombopoietin (TPO, main mediator of megakaryocyte maturation and platelet formation in the bone marrow) and glycocalicin (soluble fragment of the membrane glycoprotein Ib detached from the surface of platelets during their destruction). Specific changes in the markers of platelet production and turnover have been observed in: (i) hypoproductive thrombocytopenias caused by suppression of megakaryocytes in the bone marrow; (ii) immune thrombocytopenias caused by accelerated clearance of the autoantibody-sensitized platelets; and (iii) thrombocytosis (both primary and reactive). The paper presents the data indicating that in patients with cardiovascular diseases an increased platelet turnover and changes in the corresponding markers (platelet size indexes and content of reticulated forms) are associated with the decreased efficacy of antiplatelet drugs and increased risk of thrombotic events, myocardial infarction, and unstable angina (acute coronary syndrome).

Mean Platelet Volume as a Potential Marker of Large Vessel Occlusion and Predictor of Outcome in Acute Ischemic Stroke Patients Treated with Reperfusion Therapy

(1) Background: An early diagnosis of a large vessel occlusion (LVO) is crucial in the management of the acute ischemic stroke (AIS). The laboratory predictors of LVO and a stroke outcome remain unknown. We have hypothesized that high MPV—a surrogate marker of the activated platelet—may be associated with LVO, and it may predict a worse AIS outcome. (2) Methods: This was a retrospective study of 361 patients with AIS who were treated with thrombolysis (tPA, 65.7%) and/or mechanical thrombectomy (MT, 34.3%) in a tertiary Stroke Center between 2011 and 2019. (3) Results: The mean MPV in the cohort was 9.86 ± 1.5 fL (1st–4th quartiles: <8.8, >10.80 fL). Patients in the 4th quartile compared to the 1st had a significantly (p < 0.01) more often incidence of an LVO related stroke (75% vs. 39%) and a severe stroke manifestation with a higher RACE score (5.2 ± 2.8 vs. 3.3 ± 2.4), NIHSS at baseline (mean ± SD, 14 ± 6.5 vs. 10.9 ± 5.2), and NIHSS at discharge (6.9 ± 7 vs. 3.9 ± 3.6). A multivariate analysis revealed that quartiles of MPV (OR 1.4; 95%CI 1.2–1.8) significantly predicted an LVO stroke, also after the adjustment for RACE < 5 (OR 1.4; 95%CI 1.08–1.89), but MPV quartiles did not predict a favorable stroke outcome (mRS ≤ 2) (OR 0.89; 95%CI 0.7–1.13). (4) Conclusion: Our data suggest that MPV is an independent predictor of LVO in patients with an acute ischemic stroke.

Evaluation and comparison of the new Mindray BC-6200 hematology analyzer with ADVIA 2120i

BACKGROUND

The Mindray BC-6200 is a new automatic hematology analyzer that quantifies the parameters of blood morphology and leukocyte differential in five populations (5-Diff). The aim of the study was to evaluate the BC-6200 and compare it with the Siemens ADVIA 2120i analyzer.

MATERIALS AND METHODS

The comparison between BC-6200 and ADVIA 2120i analyzers was performed using 390 whole blood samples collected on K₃ EDTA. For the BC-6200, the carryover effect, precision, and linearity were evaluated. 138 samples were used to assess the sensitivity and flag ability, suggesting the presence of abnormal cells such as blasts, immature granulocytes, or atypical lymphocytes. Flagging results were compared with microscopic evaluation of blood smears.

RESULTS

The BC-6200 analyzer showed a high correlation (r ≥ .97) with ADVIA 2120i for most of the compared parameters except RDW (r = .8350), MPV (r = .7634), Mon# (r = .8366), Baso# (r = .9205), and NRBC (r = .3768). The BC-6200 had better correlation with microscopic evaluation for NRBC (r = .8902) compared with ADVIA 2120i (r = .5677). The BC-6200 has shown high efficiency for flagging blasts (80.4%), immature granulocytes (80.5%), and atypical lymphocytes (69.0%).

CONCLUSION

The new Mindray BC-6200 hematology analyzer provides high measurements precision and good correlation with ADVIA 2120i for most of the morphology and 5-diff parameters.

Immature platelets: a review of the available evidence

Immature platelets or reticulated platelets are newly released thrombocytes. They can be identified by their large size and high RNA cytoplasm concentration. Immature platelet fraction (IPF) represents the percentage of immature circulative platelets to the total number of platelets. The development of analytical standardization of this hematological parameter by new automated devices allowed a better exploration of its contribution in a context of thrombocytopenia. In fact, several studies had confirmed its clinical utility to differentiate immune thrombocytopenia from other causes of thrombocytopenia. IPF can also predict platelets recovery after chemotherapy and successful engraftment. In addition, immature platelets have shown utility in other diseases such as coronary artery diseases, bacterial infections and liver diseases. Despite all these advantages, immature platelet fraction can be increased in some cases of thrombocytopenia characterized by platelets hypoproduction. The aim of this review is to present the immature platelet fraction contribution in clinical practice.

Evaluation of Biomarkers for the Prediction of Venous Thromboembolism in Ambulatory Cancer Patients

BACKGROUND

Venous thromboembolism (VTE) is a common complication of cancer. This study aimed to evaluate immature platelet fraction (IPF), mean platelet volume (MPV), P-selectin, D-dimer, and thrombin generation (TG) as predictive biomarkers for VTE and further the improvement of existing risk assessment models (RAMs).

METHODS

A prospective, observational, exploratory study was conducted on ambulatory cancer patients with indication for systemic chemotherapy. Baseline RAMs included the Khorana-, Vienna Cancer, Thrombosis-, Protecht-, ONKOTEV-, and Catscore. IPF, MPV, P-selectin, D-dimer, and TG were analysed at baseline and 3-month follow-up.

RESULTS

We enrolled 100 patients, of whom 89 completed the follow-up. Frequent tumour types were breast (30%), gastric (14%), gynaecological (14%), and colorectal (14%) cancer. Ten of the 89 patients (11.2%) developed VTE. The highest VTE rate was observed in patients with cholangiocarcinoma (3/5; 60%). Baseline D-dimer levels but not IPF, MPV, or P-selectin were associated with the risk of developing VTE (HR 6.9; p = 0.021). None of the RAMs showed statistical significance in predicting VTE. Peak thrombin and endogenous thrombin potential were lower in patients who developed VTE. Biomarker changes between baseline and follow-up were not associated with VTE risk.

CONCLUSIONS

VTE risk was well predicted by baseline D-dimer levels. Adding D-dimer could improve existing RAMs to better identify patients who may benefit from primary VTE prophylaxis. The VTE risk among patients with cholangiocarcinoma should be further evaluated.

The use of mean platelet volume for distinguishing the causes of thrombocytopenia in adult patients

Establishment and analysis of mean platelet volume (MPV) may be helpful in the discrimination between underproduction or over-destruction of platelets as the causes of thrombocytopenia. The primary objective is to find the cut-off point of MPV for distinguishing causes of thrombocytopenia. The secondary objective is to validate the cut-off value of the MPV by using bone marrow examination. Thrombocytopenic patients were enrolled in a training set and a receiving operating characteristics (ROC) curve was plotted to obtain the cut-off value of MPV. A validation set of patients was recruited to validate the cut-off value. The training set included 240 patients. Half with with underproductive (n=120) and half with over-destructive thrombocytopenia (n=120). The best cut-off value of MPV was 8.8 fL. The validation set included 119 patients in total, again in 2 groups, those with underproductive (n=84) and those with overdestructive thrombocytopenia (n=35). The sensitivity, specificity, PPV and NPV when MPV ≥8.8 fL indicating over-destructive thrombocytopenia were 77%, 89%, 89% and 77%, respectively. MPV is useful for differentiating the cause of thrombocytopenia. The value of MPV ≥8.8 fL has acceptable sensitivity and specificity for diagnosis of over-destructive thrombocytopenia.

The mean platelet volume on admission predicts unfavorable stroke outcomes in patients treated with IV thrombolysis

Purpose

The role of biomarkers in the prediction of acute ischemic stroke (AIS) outcome or response to thrombolytic therapy (with recombinant tissue plasminogen activator [rt-PA]) remains limited. The aim of this study was to evaluate whether mean platelet volume (MPV) could predict short-term functional outcome in patients with AIS following rt-PA treatment.

Patients and methods

This was a retrospective analysis of 237 AIS patients (mean age 71.04±0.8 years, 50.6% women) consecutively admitted to a tertiary care center between 2011 and 2015.

Results

The mean MPV in the cohort was 9.8±0.35 fL (lowest tertile <7.29 fL, median 7.29–8.8 fL, and highest tertile >8.8 fL). Patients in the lowest tertile compared to median and highest tertiles were less often dependent (modified Rankin scale [mRS] ≥3) at admission (87.2% vs 96.1% and 96.1%, respectively, P=0.04) and less often had a poor stroke outcome (mRS 4–6) at discharge (28.2% vs 55.3% and 44.7%, P<0.01). However, there was no significant difference between tertiles with regard to AIS etiology, CT (Alberta Stroke Program Early CT) score, frequency of stroke due to large artery occlusion, risk of secondary hemorrhage, and early neurologic deterioration. Multivariable analysis after adjustment for confounders showed that patients in the second and third tertiles had a significantly higher risk of poor stroke outcome (OR =1.9, 95% CI =1.01–4), lack of early improvement (OR =1.91, 95% CI =1.05–3.47), lower chance of good outcome (mRS 0–2; OR =0.38, 95% CI =0.18–0.78), or minor stroke at discharge (OR =0.47, 95% CI =0.26–0.84). Receiver operating characteristic analysis for prediction of poor stroke outcome showed that the optimal cut-off point of MPV was 8.8 fL (area under the curve 0.586 [0.512–0.659], P=0.03) with a sensitivity of 82.7% and a specificity of 43.9%.

Conclusion

Disabling or fatal ischemic stroke in thrombolyzed patients was observed more often in patients with high admission MPV. The prognostic value of MPV was independent of other well-defined individual risk factors.

A characteristic flow cytometric pattern with broad forward scatter and narrowed side scatter helps diagnose immune thrombocytopenia (ITP)

Various disorders cause severe thrombocytopenia, which can lead to critical hemorrhage. Procedures that rapidly support the diagnosis and risk factors for serious bleeding were explored, with a focus on immune thrombocytopenia (ITP). Twenty-five patients with thrombocytopenia, including 13 with newly diagnosed ITP, 3 with chronic ITP, 6 with aplastic anemia (AA), and 3 with other thrombocytopenia (one acute myeloid leukemia, one acute lymphoblastic leukemia, and one hemophagocytic lymphohistiocytosis), were reviewed. In addition to platelet-related parameters obtained by an automated hematology analyzer, flow cytometric analysis of platelets was performed. A characteristic flow cytometric pattern with broad forward scatter and narrowed side scatter, which is specific to ITP, but not other types of thrombocytopenia, was found. CD62P-positive platelets were increased in newly diagnosed ITP cases compared to control (P < 0.0001), AA (P = 0.0032). Moreover, detection of dramatic changes in these parameters on sequential monitoring may suggest internal hemorrhage, even absent skin or visible mucosal bleeding. The bleeding score for visible mucosae had a negative correlation with platelet count and a positive correlation with immature platelet fraction (%), forward scatter, and CD62P. This characteristic flow cytometric pattern makes it possible to distinguish ITP from other thrombocytopenic disorders.

Association of mean platelet volume with risk of venous thromboembolism and mortality in patients with cancer

Venous thromboembolism (VTE) is a frequent complication in cancer patients. Mean platelet volume (MPV) has been associated with arterial and venous thrombosis in patients without cancer. We analysed MPV in cancer patients and investigated the association of MPV with risk of VTE and mortality. MPV was routinely determined in the Vienna Cancer and Thrombosis Study, a prospective, observational cohort study of patients with newly diagnosed or progressive cancer after remission. Study endpoints were occurrence of symptomatic VTE or death during a maximum follow-up of two years. Out of 1,544 included patients, 114 (7.4%) developed VTE and 573 (37.1%) died during a median observation time of 576 days. High MPV ≥75th percentile of the study population; ≥10.8 fL) was associated with decreased risk of VTE compared to MPV below the 75th percentile (HR [95% CI]: 0.59 [0.37–0.95], p=0.031). In multivariable analysis, including age, sex, cancer groups, newly diagnosed vs recurrent disease, platelet count and soluble P-selectin, this association remained statistically significant (0.65 [0.37–0.98], p=0.041). Mortality of patients with MPV (≥75th percentile was significantly decreased compared to those with lower MPV (0.72 [0.59–0.88], p=0.001). Two-year probability of VTE and overall survival was 5.5% and 64.7% in patients with high MPV compared to 9% and 55.7% in those with lower MPV. In conclusion, high MPV is associated with decreased VTE risk and improved survival in cancer patients. This finding is contrary to results observed in patients without cancer. Further studies are needed to confirm our results and elucidate underlying mechanisms.

Previous presentations of this manuscript: Data from this study were presented in part at the Annual Spring Meeting of the Austrian Society for Haematology and Oncology (OeGHO) in Linz, Austria, and as an oral presentation at the XXIV. Congress of the International Society on Thrombosis and Haemostasis (ISTH) 2013 in Amsterdam, the Netherlands.

A pilot study evaluating the prognostic utility of platelet indices in dogs with septic peritonitis

OBJECTIVE

To characterize platelet indices at time of diagnosis of septic peritonitis in dogs and to assess the relationship between platelet parameter data and survival to discharge in dogs treated surgically.

DESIGN

Retrospective, observational, descriptive pilot study from 2009 to 2014.

SETTING

University teaching hospital.

ANIMALS

Forty-eight dogs diagnosed with septic peritonitis were included in this study. Thirty-six dogs had surgical source control. Blood samples from 46 healthy control dogs were used for reference interval (RI) generation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Dogs with septic peritonitis had significantly increased mean values for mean platelet volume (MPV), plateletcrit (PCT), and platelet distribution width (PDW) with increased proportions of dogs having values above the RI compared to healthy dogs. A significantly increased proportion of dogs with septic peritonitis had platelet counts above (12.5%) and below (8.3%) the RI, with no significant difference in mean platelet count compared to healthy dogs. No significant differences in the mean platelet count, MPV, PCT, or PDW were found between survivors and nonsurvivors in dogs with surgical source control; however, dogs with MPV values above the RI had significantly increased mortality compared to dogs within the RI (P = 0.025). Values outside the RI for other platelet parameters were not associated with significant differences in mortality.

CONCLUSIONS

Dogs with septic peritonitis have increased frequency of thrombocytosis and thrombocytopenia with increased MPV, PCT, and PDW. An increased MPV may be a useful indicator of increased risk of mortality in dogs treated surgically.

Mean platelet volume predicts prognosis in patients with diffuse large B-cell lymphoma

To determine the prognostic value of baseline mean platelet volume (MPV) in diffuse large B-cell lymphoma (DLBCL) patients. We retrospectively analyzed 161 DLBCL patients who received R-CHOP chemotherapy. The associations between MPV and clinicopathological factors were assessed. A low MPV (MPV ≤ 9.1 fl, cut-off was calculated by receiver operating characteristics) was not associated with any other clinicopathological factors. Patients with MPV ≤ 9.1 fl experienced a shorter progression-free survival (PFS) (2-year PFS rate, 60.6% vs 84.0%, P = 0.003) and overall survival (OS) (2-year OS rate, 70.4% vs 87.9%, P = 0.030), compared with those with MPV > 9.1 fl. The multivariate analysis demonstrated that MPV ≤ 9.1 fl was an independent prognostic factor of OS (Hazard Ratio [HR] = 0.588, P = 0.045) and PFS (HR = 0.456, P = 0.010). Therefore, we demonstrated that low baseline MPV is an independent prognostic marker of poor outcome in patients with DLBCL.

Changes in Platelet Count and Size Indices in Adolescent Patients With Anorexia Nervosa

The significance of platelet size indices has not been widely analyzed in anorexia nervosa (AN). It seems important to get more knowledge on the easily available indices of platelet function obtained by routine complete blood count analysis in patients with AN. We analyzed platelet count (PLT), platelet distribution width (PDW), and mean platelet volume using an automated blood cell counter in 25 females with AN and healthy age- and gender-matched nonatopic controls. Mean PLT was significantly lower in patients with AN than in the control group. Platelet distribution width values in patients with AN were significantly higher than those in the controls. Platelet distribution width values significantly correlated with the disease duration and rate of body weight loss in the anorectic patients. Anorexia nervosa in adolescents is associated with a decrease in PLT along with an increased PDW, which may be an indicator of dysregulated thrombopoiesis.

Diagnostic value of platelet indices and bone marrow megakaryocytic parameters in immune thrombocytopenic purpura

Platelet indices could mirror megakaryopoietic activity in immune thrombocytopenic purpura (ITP), but its specificity and sensitivity need to be studied. The diagnostic performance of platelet indices was analyzed by receiver-operating characteristic curves, and the probability of true positive (sensitivity) and true negative (specificity) in predicting ITP, myelodysplasia, or controls was determined. Mean platelet volume (MPV) was higher, whereas plateletcrit (PCT) was significantly lower in ITP than in myelodysplasia and controls. The platelet distribution width in ITP patients was lower than in myelodysplasia, but higher than in controls. Increased megakaryocytes were only observed in ITP. A strong positive correlation was found between MPV and quantities of granular megakaryocytes, whereas a negative relationship existed between MPV and platelet-form megakaryocytes. In receiver-operating characteristic analysis, MPV and PCT gave a sensitivity of 70.3% (89.8%) and specificity of 74.8% (84.7%) at a cutoff of 9.35 (0.085) in diagnosis of ITP. Combined parallel test of MPV and PCT increased the sensitivity to 97.5 with 64.1% specificity, whereas series test increased the specificity to 94.7 with 62.7% sensitivity. Our results suggest that MPV, PCT, and platelet distribution width represent megakaryopoietic activity in bone marrow and may be reliable markers in ITP diagnosis.

No associations exist between mean platelet volume or platelet distribution width and thyroid function in Chinese

Mean platelet volume (MPV) and platelet distribution width (PDW) are morphometric indices of size distribution and variability of platelet. We aimed to explore the associations between MPV or PDW and thyroid function in a large Chinese cohort.This was a cross-sectional study with a recruitment of 13,622 self-reported healthy Chinese (8424 males, 5198 females). Clinical data of the participants comprised of anthropometric measurements, hepatic function, renal function, serum levels of lipid, glucose, C-reactive protein, erythrocyte sedimentation rate, platelet, MPV, PDW, and thyroid hormones. Database was sorted by sex, and the associations between MPV or PDW and thyroid function were analyzed by quartiles of MPV or PDW. Levels of MPV and PDW were compared in different thyroid function subgroups by 1-way analysis of variance and independent sample's t test. Receiver-operating characteristic (ROC) curve was adopted to determine diagnostic values of MPV and PDW for thyroid dysfunction. Crude and adjusted odds ratios of MPV and PDW for thyroid dysfunction with 95% confidence intervals were analyzed by binary logistic regression models.MPV, PDW, and thyroid stimulation hormone were significantly higher in females than in males. Females showed significantly higher incidence of hypothyroidism and hyperthyroidism than males. However, there were no significant differences of MPV and PDW among different thyroid function subgroups in both sexes, and no obvious correlations were revealed between MPV or PDW and thyroid function. From ROC analysis, we demonstrated no diagnostic values of MPV and PDW for thyroid dysfunction. From binary logistic regression models, no risks of different MPV and PDW quartiles were identified for thyroid dysfunction in both sexes.We could not show any association between MPV or PDW and thyroid function. Prospective studies with better defined risk groups should be performed in the future for further verification and validation.

Optimized gating and reference ranges of reticulated platelets in dogs for the Sysmex XT-2000iV

Background

Canine reticulated platelets (r-PLTs) i.e., juvenile PLTs reflecting thrombopoiesis can be measured automatically with the hematology analyzer Sysmex XT-2000iV using manual gating options. However, the impact of interferences on r-PLT measurements performed with the gates published previously (Pankraz et al., Vet Clin Path 38:30–38, 2009; Gelain et al., High fluorescent platelets fraction in macrothrombocytopenic Norfolk terrier, 2010) is largely unknown.

The aim was to compare different published gates for measurement of r-PLTs with the Sysmex XT-2000iV with an own, optimized gate (“Oellers-gate”) and to establish reference intervals (RIs) in > 120 dogs.

Data of 362 measurements of diseased and healthy dogs were analyzed retrospectively. Several gates were applied and RIs for r-PLTs and platelet indices were established for pet dogs and a group of 153 healthy Beagles kept under defined housing conditions. Intra-assay precision (CV) was also assessed.

Results

In 30/362 samples, interferences consistent with small erythrocytes/reticulocytes were seen in the previously published gates but not in the “Oellers-gate”. Good correlation was found between the different gates (r_s: 0.88–1.00). RIs for the “Pankraz-gate”, the “Gelain-gate”, and the “Oellers-gate” were 0.0–1.2, 0.2–3.7 and 0.2–3.9 % respectively. CVs were ranging between 22 and 41 %.

Conclusions

Optimization of previously published gates minimized interferences of small erythrocytes with r-PLT measurements.

Diagnostic predictive value of platelet indices for discriminating hypo productive versus immune thrombocytopenia purpura in patients attending a tertiary care teaching hospital in Addis Ababa, Ethiopia

Background

Bone marrow examination may be required to discriminate causes of thrombocytopenia as hypoproductive or hyperdestructive. However, this procedure is invasive and time consuming. This study assessed the diagnostic value of Mean Platelet Volume (MPV), Platelet Distribution Width (PDW) and Platelet Large Cell-Ratio (P-LCR) in discriminating causes of thrombocytopenia as hypoproductive or hyperdestructive (Immune thrombocytopenia purpura).

Method

A prospective cross-sectional study was conducted on 83 thrombocytopenic patients (Plt < 150 × 10⁹/L). From these, 50 patients had hypoproductive and the rest 33 Immune Thrombocytopenia Purpura (ITP). Age and sex matched 42 healthy controls were included as a comparative group. Hematological analysis was carried out using Sysmex XT 2000i 5 part diff analyzer. SPSS Version16 was used for data analysis. A two by two table and receiver operating characteristic (ROC) curve was used to calculate sensitivity, specificity, positive and negative predictive values, for a given platelet indices (MPV, PDW and P-LCR). Student t test and Mann Whitney U test were used to compare means and medians, respectively. Correlation test was used to determine associations between continuous variables.

Results

All Platelet indices were significantly higher in ITP patients (n = 33) than in hypoproductive thrombocytopenic patients (n = 50) (p < 0.0001). In particular MPV and P-LCR have larger area under ROC curve (0.876 and 0.816, respectively), indicating a better predictive capacity, sensitivity and specificity in discriminating the two causes of thrombocytopenia. The indices were still significantly higher in ITP patients compared to 42 healthy controls (p < 0.0001). A significant negative correlation was observed between platelet count and platelet indices in ITP patients, (p < 0.001).

Conclusion

MPV, PDW and P-LCR help in predicting thrombocytopenic patients as having ITP or hypoproductive thrombocytopenia. If these indices are used in line with other laboratory and clinical information, they may help in delaying/ avoiding unnecessary bone marrow aspiration in ITP patients or supplement a request for bone morrow aspiration or biopsy in hypoproductive thrombocytopenic patients.

Is the preoperative MPV value related to early thrombus formation in microvascular anastomosis?

OBJECTIVE

One of the most common encountered problems in free flap surgeries is anastomotic thrombosis. The mean platelet volume (MPV) may indicate the concentration of intra-platelet proactive substances and the thrombogenic potential of the platelets. MPV is used as a clinical monitoring index in routine blood counts, it has not yet been effectively used in free flap surgery.

METHODS

This study evaluates the relationship between the preoperative MPV value and anastomotic thrombus formation during the postoperative 48 hours in 32 free flap operations from September 2013 to September 2014. The mean patient age was 36.75 years. The preoperative MPV value, which was obtained from the complete blood count, was recorded and correlation of MPV and postoperative thrombus formation was investigated.

RESULTS

Four anastomotic thrombus were encountered in 34 free flaps during the postoperative 48 hours. Two of them were salvaged by performing thrombectomy and/or administration of i.v. heparin. There was no statistical relationship between MPV value and postoperative thrombus formation during 48 hours follow-up (p = 0.925).

CONCLUSION

Even though this study didn't find a correlation between preoperative MPV value and postoperative early anastomotic thrombus, it would be helpful to validate the results using multi-centre and comprehensive studies with larger patient cohorts.

The role of mean platelet volume in patients with non-specific abdominal pain in an emergency department

Introduction

Platelets play an important role in inflammation. Mean platelet volume (MPV) may be a useful parameter for inflammatory conditions, in differentiating between non-specific abdominal pain (NSAP) and conditions requiring surgery, or early diagnosis of abdominal pain as a serious problem for emergency services.

Aim

To investigate the role of MPV on NSAP admittance to the emergency department.

Material and methods

The study consisted of 330 patients (186 female and 144 male, with mean age 49 ±20 years) with NSAP and 249 patients with abdominal pain (144 female and 105 male, with mean age 49 ±19 years) applied to our emergency service and enrolled to our study. Medical history, physical examination, complete blood count (CBC), and biochemical parameters were evaluated. Haematological parameters were measured by Beckman Coulter LH 780 instrument. Data were compared using Student's t test, and p < 0.05 was accepted as statistically significant.

Results

The MPV were significantly lower in patients with NSAP than in others (p = 0.025). There was no significant difference between both sexes with regard to MPV (p > 0.05). Moreover, the other haematological parameters (haemoglobin, platelet, or WBC counts) were not statistically different between both groups (p > 0.05).

Conclusions

The MPV may be a useful, simple, and inexpensive parameter to diagnose or differentiate between NSAP and other conditions.

Hantavirus infection-induced thrombocytopenia triggers increased production but associates with impaired aggregation of platelets except for collagen

INTRODUCTION

We evaluated the mechanisms of thrombocytopenia encountered in hantavirus disease by studying platelet production together with platelet aggregation and deposition to collagen surface.

PATIENTS AND METHODS

The study group consisted of 31 prospectively recruited, consecutive, hospitalized patients having acute Puumala hantavirus infection. Blood samples were collected acutely and at the control visit and subjected to analysis in Sysmex® XE-5000 to capture mean platelet volume (MPV) and immature platelet fraction (IPF%). Platelet aggregation under low shear rate conditions was assessed with impedance aggregometry Multiplate®, whereas platelet function analyzer (PFA)-100® was applied under blood flow of high shear forces.

RESULTS

IPF% was 3.1-fold higher acutely compared with the control (median 7.4%, range 2.0-23.8% vs. median 2.4%, range 1.4%-5.2%, p<0.001) tightly associating with the low platelet count (r=-0.76, p<0.001). Accordingly, acute MPV was high (median 11.4f l, range 9.4-13.1 fl vs. median 10.5 fl, range 9.0-12.0 fl, p=0.003). Acute platelet aggregation in Multiplate® was decreased to all agonists compared with the later control (p<0.05 for all agonists). Aggregation capacity associated with thrombocytopenia (for all agonists r ≥ 0.81, p<0.001), but impaired aggregation occurred also among patients with a nearly normal platelet count. Triggered by collagen, 20% of values were below reference range, while 73% of responses were low with thrombin receptor activating peptide. Significantly, under high shear platelet deposition to collagen surface was normal despite thrombocytopenia.

CONCLUSIONS

During acute hantavirus disease, platelet aggregation is impaired especially when induced with thrombin. Platelet adhesive mechanisms on collagen are intact despite thrombocytopenia while thrombopoiesis is active.

Evaluation of the diagnostic performance of platelet-derived indices for the differential diagnosis of thrombocytopenia in pediatrics

<p>Background. Platelet-derived indices have a well-established correlation with the differential diagnosis of thrombocytopenia in adult-based research. These indices include mean platelet volume, platelet distribution width, and platelet-large cell ratio.</p><p>Objective. To determine the values of platelet-derived indices in a pediatric population with diagnoses of thrombocytopenia and their etiologic correlation.</p><p>Materials and methods. Analytic observational diagnostictest study. The population for this analytical study was pediatric patients between 6 months and 18 years of age who had thrombocytopenia (&lt;100x109/L). The study period was 18 months long.</p><p>Results. Of 54 subjects, 18 (33.3%) were diagnosed with idiopathic thrombocytopenic purpura, and 36 (66.7%) were diagnosed with acute leukemia. Mean age was 7.4 years and 6.8 years for immune thrombocytopenic purpura and acute leukemia, respectively. Mean platelet distribution width values for immune thrombocytopenic purpura and acute leukemia were 15.08 fL and 10.73, respectively. Mean MPV for immune thrombocytopenic purpura and acute leukemia was 11.7 fL and 9.8 fL, respectively. Mean platelet-large cell ratio was 38.26% and 24.97% for idiopathic thrombocytopenic purpura and acute leukemia, respectively. Differences in these three distinct platelet indices between idiopathic thrombocytopenic purpura and acute leukemia were statistically significant (p=0.00). The area under the ROC curve for platelet-derived indices showed that they were adequate for defining the causes of thrombocytopenia. MPV and platelet-large cell ratio had an area under the curve of 0.89 and 0.88, respectively, while platelet size deviation width had an area under the curve of 0.903.</p><p>Conclusions. Platelet-derived indices could be useful in the initial approach for the differential diagnosis of pediatric patients with thrombocytopenia.</p>

Platelets: the few, the young, and the active

Many modern automated cell counters in high-volume clinical hematology laboratories use new, improved technologies for routine platelet analysis. The latest progress includes the use of state-of-the art information technology, specific fluorescent dyes, and monoclonal antibodies to obtain more reliable platelet counts. This information allows the accurate and precise enumeration of platelets even in thrombocytopenic patients and the reporting of novel platelet parameters. In the near future, digital image analysis may permit even better platelet analysis.

Relationships of mean platelet volume and plasma thrombopoietin with glycocalicin levels in thrombocytopenic patients

BACKGROUNDS/AIMS

Relationships of mean platelet volume (MPV) and thrombopoietin (TPO) with platelet turnover assessed by glycocalicin measurement were evaluated in thrombocytopenic patients.

METHODS

MPV, glycocalicin and platelet-associated IgG (PA-IgG) were measured in 107 patients with idiopathic thrombocytopenic purpura (ITP) and 19 patients with hypoproductive thrombocytopenia (HPT; aplastic anemia or leukemia), and TPO was measured in 53 ITP and 12 HPT patients. All the included ITP patients had PA-IgG ≥300% and glycocalicin ≥50% of control values, and HPT patients had PA-IgG <300% and glycocalicin <50% of control values.

RESULTS AND CONCLUSIONS

MPV was higher in ITP than in HPT patients: 9.56 ± 1.69 and 7.59 ± 0.90 fl (p < 0.001). In the ITP group a direct correlation was detected between MPV and glycocalicin (r = 0.344, p < 0.001). This interaction was essentially expressed in patients with normal/increased glycocalicin (≥100% of control; r = 0.470, p < 0.001, n = 64). TPO was greatly enhanced in HPT in comparison with ITP patients (958 ± 659 and 11 ± 27 pg/ml, p < 0.001). In the ITP group a reverse correlation was detected between TPO and glycocalicin (r = -0.373, p = 0.006).

Clinical significance of platelet-associated hematological parameters as an early supplementary diagnostic tool for sepsis in thrombocytopenic very-low-birth-weight infants

Sepsis is an important cause of death in very-low-birth-weight (VLBW) neonates. Although conventional diagnostic indicator of sepsis has been done by blood cultures, this took much longer time. The measurement of platelet-associated parameters such as mean platelet volume (MPV) and platelet distribution width (PDW) become more reliable and accurate parameters as a non-specific marker for sepsis. Our objective is to examine the usefulness of those platelet hematological parameters as a supplementary diagnostic tool for sepsis in VLBW infants. This study is a retrospective cohort study of neonates subject to the diagnosis of sepsis from October 2006 to July 2010. This study was conducted at Korea University medical center. We studied total 2,336 infants for 32 days from birth (Day 0) to Day 31. We compared three groups of infants to examine differences of platelet parameters according to their age from birth to Day 31: (i) full-terms versus VLBW without sepsis, (ii) VLBW without sepsis versus VLBW with sepsis and (iii) thrombocytopenic VLBW without sepsis versus those with sepsis. The platelet-associated parameters were significantly distinguishable between septic and non-septic groups at their early age (∼ 1 week), especially platelet counts (PLT) (p = 0.0091), MPV (p = 0.007) and PDW (p = 0.0372) in thrombocytopenic VLBW infants. The decreased PLT, elevated MPV and PDW were major characteristics of septic group. We suggested maximum cutoff values of the platelet factors by performing receiver operating characteristic curve analysis between septic and non-septic thrombocytopenic VLBW infants, among which MPV was the most promising index (AUCMPV = 0.7044 > AUCPLT = 0.6921 > AUCPDW = 0.6593). Platelet-associated hematological parameters are useful for the early diagnosis of sepsis as a more efficient and supplementary diagnostic method in thrombocytopenic VLBW infants.

Platelet indices are novel predictors of hospital mortality in intensive care unit patients

BACKGROUND AND OBJECTIVE

Platelet volume indices (PVIs) are inexpensive and readily available in intensive care units (ICUs). However, their association with mortality has never been investigated in a critical care setting. Our study aimed to investigate the association of PVI and mortality in unselected ICU patients.

METHODS

This was a retrospective study conducted in a mixed 24-bed ICU from September 2010 to December 2012. Platelet indices including mean platelet volume (MPV), platelet distribution width (PDW), platelet count, and plateletcrit were measured on ICU entry. Univariable analyses were performed to screen for variables that were associated with mortality. Variables with P < .1 were incorporated into a regression model to adjust for the odds ratio of platelet indices.

RESULTS

A total of 1556 patients were included during the study period, including 1113 survivors and 443 nonsurvivors (mortality rate: 28.47%). Platelet distribution width and MPV were significantly higher in nonsurvivors than in survivors. Platelet distribution width greater than 17% and MPV greater than 11.3 fL were independent risk factors for mortality (adjusted odds ratio: 1.92 and 1.84, respectively) and survival time (hazards ratio: 1.77 and 1.75, respectively).

CONCLUSION

Higher MPV and PDW are associated with increased risk of death, whereas the decrease in plateletcrit is associated with increased mortality risk.

An overview of platelet indices and methods for evaluating platelet function in thrombocytopenic patients

Thrombocytopenia is associated with bleeding risk. However, in thrombocytopenic patients, platelet count does not correlate with bleeding risk and other factors are thus likely to contribute to this risk. This review presents currently available platelet-related markers available on automated haematology analysers and commonly used methods for testing platelet function. The test principles, advantages and disadvantages of each test are described. We also evaluate the current literature regarding the clinical utility of the test for prediction of bleeding in thrombocytopenia in haematological and oncological diseases. We find that several platelet-related markers are available, but information about the clinical utility in thrombocytopenia is limited. Studies support that mean platelet volume (MPV) can aid diagnosing the cause of thrombocytopenia and low MPV may be associated with bleeding in thrombocytopenia. Flow cytometry, platelet aggregometry and platelet secretion tests are used to diagnose specific platelet function defects. The flow cytometric activation marker P-selectin and surface coverage by the Cone-and-Plate[let] analyser predict bleeding in selected thrombocytopenic populations. To fully uncover the clinical utility of platelet-related tests, information about the prevalence of platelet function defects in thrombocytopenic conditions is required. Finally, knowledge of the performance in thrombocytopenic samples from patients is essential.

Mean platelet volume reflect hematopoietic potency and correlated blood group o in cord blood from healthy newborn

We evaluated the relationship between mean platelet volume (MPV) and characteristics of 10,577 cord blood (CB) units in a public CB bank in Korea. Blood group O has the highest MPV (P = 0.002). MPV correlated with CB volume (r = 0.121), Hb (r = 0.377), WBC (r = 0.111), TNCs (r = 0.110), CD34+ cell (r = 0.174), CD34+ cells/TNCs (r = 0.157), gestational age (r = −0.102), and birth weight (r = 0.023); (P < 0.001 in all). MPV may be one of the useful decision parameters of process priority in CB bank.

Platelet counting

Platelet counting is a daily basic hematological analysis of crucial interest in many clinical situations. Historical manual techniques (phase-contrast microscopy) have been replaced by automated techniques (impedance or optical analyzers) more rapid and precise. More recently, flow cytometry techniques using labeled monoclonal antibodies have been proposed as reference techniques. Nevertheless, pre-analytical and analytical variables should be respected to obtain reliable results and avoid validation pitfalls.

Are platelet volume indices of clinical use? A multidisciplinary review

Platelet size correlates with platelet activity and can be assessed by platelet volume indices (PVI). The PVI, mean platelet volume (MPV), is universally available with routine blood counts by automated hemograms and therefore is an attractive index to study in clinical scenarios. PVI are useful in assessing the etiology of thrombocytopenia. In addition, a normal platelet distribution width in the setting of thrombocytosis is highly suggestive of a reactive etiology. Higher MPV is also associated with the presence of cardiovascular risk factors, chest pain due to acute coronary syndrome, and adverse outcome after acute coronary syndrome. Results from studies evaluating MPV in patients with peripheral artery disease, unprovoked deep vein thrombosis, and pulmonary embolism further advocate a potential role for MPV in identifying patients at high risk of thrombosis. Nevertheless, most of these data come from retrospective studies some of which have small study populations and confounding factors influencing platelet volume. Moreover, the cut-off values derived from these retrospective studies have not been validated prospectively. Despite the potential for clinical utility evident from these studies, the above-mentioned flaws together with technical problems in measuring MPV currently limit its clinical usefulness. Our review provides a perspective on PVI's potential clinical use.

Platelet volume indices have low diagnostic efficiency for predicting bone marrow failure in thrombocytopenic patients

The aim of the present study was to evaluate the predictive efficiency of mean platelet volume (MPV) and platelet size deviation width (PDW) for bone marrow failure (BMF) in thrombocytopenic patients. Platelet count, MPV and PDW data were retrieved from the records of 574 unselected thrombocytopenic patients from between March 2010 and March 2011, of which 182 patients with a platelet count <20×10⁹/l were excluded from further study. A total of 392 valid thrombocytopenic patients were included in the present study and divided into two groups: 124 patients with idiopathic thrombocytopenia purpura (ITP) and 268 with BMF. The predictive efficiency of MPV and PDW were tested for the diagnosis of BMF. Significant differences were observed in the age distribution, platelet count, MPV and PDW between the ITP and BMF groups. The platelet count was positively correlated with MPV and PDW in the patients with ITP but not BMF. The negative-predictive values of MPV and PDW for BMF were 59.3 and 58.9%, respectively, with an MPV threshold of ≥11.0 fl and a PDW threshold of <16.0%. The positive-predictive values of MPV and PDW for BMF were 88.4 and 83.9%, respectively, with an MPV threshold <8.0 fl and a PDW threshold ≥17.5%. The areas under the curves (AUCs) of MPV and PDW were 0.281 and 0.700, respectively, for the diagnosis of BMF. The negative and positive-predictive values of MPV for BMF at different thresholds were not as conclusive as described in previous studies. MPV and PDW do not have sufficient specificity and sensitivity for the diagnosis of BMF in thrombocytopenic patients.