Immature platelet fraction measurement in patients with chronic liver disease: a convenient marker for evaluating cirrhotic change

Platelet Subtypes in Inflammatory Settings

In addition to their essential role in hemostasis and thrombosis, platelets also modulate inflammatory reactions and immune responses. This is achieved by specialized surface receptors as well as secretory products including inflammatory mediators and cytokines. Platelets can support and facilitate the recruitment of leukocytes into inflamed tissue. The various properties of platelet function make it less surprising that circulating platelets are different within one individual. Platelets have different physical properties leading to distinct subtypes of platelets based either on their function (procoagulant, aggregatory, secretory) or their age (reticulated/immature, non-reticulated/mature). To understand the significance of platelet phenotypic variation, qualitatively distinguishable platelet phenotypes should be studied in a variety of physiological and pathological circumstances. The advancement in proteomics instrumentation and tools (such as mass spectrometry-driven approaches) improved the ability to perform studies beyond that of foundational work. Despite the wealth of knowledge around molecular processes in platelets, knowledge gaps in understanding platelet phenotypes in health and disease exist. In this review, we report an overview of the role of platelet subpopulations in inflammation and a selection of tools for investigating the role of platelet subpopulations in inflammation.

Reticulated Platelets-Which Functions Have Been Established by In Vivo and In Vitro Data?

Reticulated platelets (RP) are the youngest platelet fraction released into the circulation. These immature platelets have increased RNA content, a larger cell volume, more dense granules, higher levels of surface activation markers and are thought to be more reactive compared to their mature counterparts. RP have been associated with cardiovascular disease, diabetes and increased mortality. Yet only a few animal studies investigating RP have been conducted so far and further investigations are warranted. Established methods to count RP are flow cytometry (staining with thiazole orange or SYTO13) or fully automated hematology analyzers (immature platelet fraction, IPF). IPF has been established as a diagnostic parameter in thrombocytopenia, cardiovascular disease and, in particular, the response to antiplatelet therapy. This review seeks to provide an overview of the key features of RP as well as preanalytical and analytical aspects that need to be considered when working with this platelet population.

Immature Platelet Dynamics in Immune-Mediated Thrombocytopenic States

A major challenge encountered by clinicians is differentiating presentations characterized by significant thrombocytopenia due to overlapping clinical symptoms and signs in the setting of ambiguous laboratory results. Immature platelets represent the youngest platelets that can be measured in peripheral blood by current hematology analyzers. These young platelets are larger, with higher RNA content recently released from the bone marrow. Thrombocytopenic presentations caused directly or indirectly by immune responses can lead to compensatory bone marrow responses seeking to normalize the platelet count; thus obtaining absolute immature platelet counts may be informative while triaging patients. Over the last decade, their use has expanded beyond being an early biomarker of bone marrow reconstitution post-hematopoietic stem cell transplantation to being used to establish bone marrow responses to infection and thrombocytopenias due to immune etiologies. Its accessibility as part of more detailed platelet indices obtained with routine laboratories makes it a promising option to understand the bone marrow's real-time response to disease states characterized by thrombocytopenia. This review will look at the immature platelet count as a biomarker, while presenting current attempts trying to understand how it could be used in thrombocytopenias occurring secondary to a given immune etiology.

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.

Immature platelet fraction based diagnostic predictive scoring model for immune thrombocytopenia

BACKGROUND/AIMS

The diagnosis of immune thrombocytopenia (ITP) is based on clinical manifestations and there is no gold standard. Thus, even hematologic malignancy is sometimes misdiagnosed as ITP and adequate treatment is delayed. Therefore, novel diagnostic parameters are needed to distinguish ITP from other causes of thrombocytopenia. Immature platelet fraction (IPF) has been proposed as one of new parameters. In this study, we assessed the usefulness of IPF and developed a diagnostic predictive scoring model for ITP.

METHODS

We retrospectively studied 568 patients with thrombocytopenia. Blood samples were collected and IPF quantified using a fully-automated hematology analyzer. We also estimated other variables that could affect thrombocytopenia by logistic regression analysis.

RESULTS

The median IPF was significantly higher in the ITP group than in the non-ITP group (8.7% vs. 5.1%). The optimal cut-off value of IPF for differentiating ITP was 7.0%. We evaluated other laboratory variables via logistic regression analysis. IPF, hemoglobin, lactate dehydrogenase (LDH), and ferritin were statistically significant and comprised a diagnostic predictive scoring model. Our model gave points to each of variables: 1 to high hemoglobin (> 12 g/dL), low ferritin (≤ 177 ng/ mL), normal LDH (≤ upper limit of normal) and IPF ≥ 7 and < 10, 2 to IPF ≥ 10. The final score was obtained by summing the points. We defined that ITP could be predicted in patients with more than 3 points.

CONCLUSION

IPF could be a useful parameter to distinguish ITP from other causes of thrombocytopenia. We developed the predictive scoring model. This model could predict ITP with high probability.

Reticulated platelets and immature platelet fraction: Clinical applications and method limitations

So-called "reticulated" or "immature platelets," which are newly released into the circulation, are more reactive than mature platelets, contain more RNA, and can be counted using flow cytometry after staining with thiazole orange or using some fully automated hematology analyzers, albeit with numerical disagreement. This review provides an overview of the state of the art of available technology for measuring immature or reticulated platelets (RP) with preanalytical (time stability, biological variation), analytical (methods, imprecision), and postanalytical (reference range) limitations. We also analyzed the clinical conditions in which immature/RP can be considered a diagnostic or prognostic tool (ie, differential diagnosis of thrombocytopenia, recovery after bone marrow or stem cell transplantation, risk assessment in cardiovascular diseases, response to antiplatelet drugs). They might also be of clinical utility in other settings but with lower evidence. The lack of a specific reference method and universal control material, as well as dependency of results on the measurement technique used, calls for different reference intervals and compromises comparison between clinical studies carried out using different analytical methods. To obviate lack of agreement between methods, more specific RNA dyes are necessary and the impact of the platelet size on the fluorescence signal defined. In the harmonization age, also in nomenclature field, a new definition instead of "reticulated" or "immature" platelets would be useful, and "young platelets" might be a more appropriate definition taking into account both the age and the functionality of this platelet fraction.

A Review on Clinical, Pathophysiological, and Diagnostic Hematological Features in Children With Liver Cirrhosis

Appropriate diagnostic and therapeutic measures for liver cirrhosis is critical, particularly in children. In the present review, a comprehensive approach was provided toward hematological parameters in pediatric liver cirrhosis. The literature search included MeSH terms "liver cirrhosis" and "hepatic cirrhosis" and databases such as PubMed, Web of Science, Scopus, and Google Scholar were searched up until December 2017. Hematologic changes in the liver cirrhosis mainly encompassed anemia and coagulopathies. In addition, bleeding diathesis was considered as the most clinical complication in these patients. In addition to reduced coagulation factors, hyperfibrinolysis is a common feature in childhood cirrhosis and may be an important contributor to the risk of bleeding. Based on the results, children with liver cirrhosis also demonstrated a procoagulant state at laboratory and clinical levels. This may be partly due to a reduction in coagulation inhibitors such as anti-thrombin, C1 inhibitor, and α1-antitrypsin in children with cirrhosis. The portal vein thrombosis and portal hypertension are considered as the most clinical presentations of the hypercoagulable state. Further, children with liver cirrhosis complicated with portal hypertension usually show leukopenia, anemia, and thrombocytopenia due to hypersplenism. Although the etiology of childhood and adult cirrhosis may be different, their hematological compilations and clinicopathological features are somehow similar.

Immature platelet fraction and thrombopoietin in patients with liver cirrhosis: A cohort study

BACKGROUND AND AIMS

Thrombocytopenia occurs frequently in patients with cirrhosis. The immature platelet fraction (IPF%) is measured to differentiate the causes of thrombocytopenia. To date the relevance of thrombopoietin (TPO) in the context of cirrhosis is unknown. The aim of our study was to investigate the cause of thrombocytopenia in patients with liver cirrhosis by measuring IPF%, TPO and spleen size. In addition we examined the use of IPF% to evaluate the severity of cirrhosis and its complications.

METHODS

Overall, we included 88 in-patients with cirrhosis in our study. The collected data comprises current health status, blood parameters, severity of cirrhosis evaluated by Child-Pugh score and MELD score, spleen diameter, ascites and esophageal varices. The IPF% was measured using an automatic hematology analyzer. TPO was measured with ELISA.

RESULTS

IPF% (p = 0.003) and spleen diameter (p = 0.001) were significantly higher in patients with thrombocytopenia. There was no significant difference in TPO between patients with and without thrombocytopenia. The mean values of IPF% varied significantly (p = 0.044) in Child-Pugh stages. IPF% was significantly (p = 0.005) elevated in patients with esophageal varices. Moreover, IPF% higher than 3.85% displayed sensitivity of 76.6% and specificity of 52.4% with an area under receiver operating curve characteristics of 0.669 for the presence of esophageal varices.

CONCLUSION

On closer examination of the three compartments known to have an influence on platelet count splenomegaly seems to be the major cause of thrombocytopenia in patients with cirrhosis according to current knowledge. Higher IPF% in patients with thrombocytopenia indicates peripheral consumption of platelets. The relation between spleen diameter and platelet count indicates the spleen to be the major place of platelets' consumption. TPO did not differ between patients with and without thrombocytopenia. Furthermore, we cannot exclude an influence of impaired thrombopoietin synthesis on platelet counts. The association between IPF% and platelet count suggests that there is physiological regulation of platelets in patients with cirrhosis. In our study IPF% is associated with esophageal varices and the stage of cirrhosis. Further studies are needed to confirm these results.

Liver and kidney function and complications in patients with different types of hepatorenal syndrome

AIM: To explore the liver and kidney function and complications in patients with hepatorenal syndrome (HRS) of different types.

METHODS: Ninety-six patients with HRS were randomly divided into either a typeⅠHRS group (n = 63) or a type Ⅱ HRS group (n = 63). All of them received routine treatment. The INR, SCr, TBil, Alb, Child-Pugh classes, MELD scores and complications were compared between the two groups.

RESULTS: The levels of SCr and TBil in the type ⅠHRS group were higher than those in the type Ⅱ HRS group (448.08 mmol/L ± 180.33 mmol/L vs 159.94 mmol/L ± 28.16 mmol/L, 262.80 mmol/L ± 159.08 mmol/L vs 125.04 mmol/L ± 76.43 mmol/L, P < 0.05 for both). There were no significant differences in the levels of INR and Alb (2.09 g/L ± 0.68 g/L vs 1.73 g/L ± 0.45 g/L, 26.72 g/L ± 4.73 g/L vs 23.99 g/L ± 9.89 g/L, P > 0.05 for both) or Child-Pugh classes (0.00% vs 0.00%, 18.18% vs 25.40%, 81.82% vs 74.60%, P > 0.05 for all). As to MELD scores, the percentage of cases with a MELD score between 10-19 was significantly lower in the typeⅠHRS group than in the type Ⅱ HRS group (6.06% vs 57.14%, P < 0.05), but the percentages of cases with a MELD score between 30-39 and > 40 were significantly higher in the typeⅠHRS group than in the type Ⅱ HRS group (39.39% vs 3.17%, 12.12% vs 0.00%, P < 0.05 for both). The rates of ascites and infection in the typeⅠHRS group were higher than those in the type Ⅱ HRS group (78.79% vs 53.97%, 75.76% vs 42.86%, P < 0.05), although there were no significant differences in the rates of digestive tract hemorrhage and hepatic encephalopathy (21.21% vs 39.68%, 72.73% vs 57.14%, P > 0.05 for both).

CONCLUSION: Child-Pugh class, MELD score and indexes of liver function can be used to assess the condition and prognosis of patients with hepatorenal syndrome. The survival rate can be improved by reasonable treatment and efficient prevention of complications.

Changes in platelet functional parameters and CD62 P expression in liver cirrhosis

BACKGROUND

Hepatic impairment, portal hypertension, and multi-systemic damage could occur during liver cirrhosis's late stage. Bleeding is a complication of hepatic cirrhosis along with several changes including blood platelet count (BPC), mean platelet volume (MPV), platelet crit (PCT) and expression of platelet CD62P. Blood platelet count (BPC), mean platelet volume (MPV), platelet distribution width, and other indices are indirect reflections of CD62P parameters.

OBJECTIVE

To investigate the changes in platelet functional parameters and CD62 P expression in liver cirrhosis as a possible guide in clinical treatments and prognoses of liver cirrhosis.

METHODS

CD62P was tested by flow cytometry in liver cirrhosis. BPC, MPV, and PCT in peripheral blood were tested using an auto blood cell analyzer. Data were analyzed using SPSS11.0.

RESULTS

The values of CD62P and MPV in patients was significantly higher than those of healthy donors (P<0.01), while the values of BPC and PCT were significantly lower than those of the control group (P<0.01).

CONCLUSIONS

CD62P, BPC, MPV, and platelet crit (PCT) show several changes in liver cirrhosis. It is useful to understand the relationship between hepatic cirrhosis severity and CD62P, BPC, MPV, PCT, timely monitoring of CD62P for treatment of hepatic cirrhosis in clinical treatment and prognosis.