Immature Platelet Fraction Values Research Articles

Immature platelet fraction in children infected with dengue fever

Background: Millions are infected with dengue every year. Early diagnosis of dengue infection is important for proper treatment of DHF and DSS to avoid fatal outcome. Thrombocytopenia is a common hematological abnormality in dengue, which demands platelet transfusion in most of the severe dengue cases. Platelet transfusion though life-saving has its own hazards. Hence, we can use some new parameter like immature platelet fraction (IPF) which is a measure of reticulated platelets that reflects the rate of thrombopoiesis. The risk of platelet transfusion may be decreased by rapid identification of immature platelet fraction. This study was performed to establish reference of IPF values for the assessment of thrombopoiesis.Methods: Blood samples from 150 children were obtained on day of illness 3, 5 and 7. The IPF is identified by sysmex XE2100 hematology analyser in the reticulocyte channel using a fluorescent dye and a carefully designed gating system and counted by a special software termed IPF master7. IPF values against platelet count were assessed separately on day 3, 5 and 7.Results: The reference intervals of IPF > 8 % and IPF < 8 % were assessed against platelet count. Increase in IPF favored increase in platelet count on day 5 which was statistically significant with the p value <0.001.Conclusions: A rapid and inexpensive automated measurement of IPF can be integrated as a standard parameter to evaluate the thrombopoietic state of the bone marrow. From the study it can be concluded that IPF is an important predictor of increase in platelet count. Increase in IPF>8 % suggests that platelet count will be increased in next 24 to 48hrs indicating that further blood transfusion will not be required.

Relationship Between Immature Platelet Fraction and Platelet Count among Pediatric Patients with Dengue Fever: A Prospective Cross-Sectional Study

Background and Objectives: Immature platelet fraction (IPF) is a new hematologic parameter that reflects the rate of thrombopoiesis. It has been suggested to be a predictor of platelet recovery in patients with thrombocytopenia. This study aimed to determine the relationship between IPF and platelet count among pediatric patients with thrombocytopenia due to dengue fever. Methods: This was a prospective cross-sectional study of 77 thrombocytopenic pediatric dengue fever patients. IPF was included in the daily complete blood count extraction. Baseline and daily IPF, platelet count, hematocrit, white blood cell count and presence of fever were recorded according to day of illness. The pattern of IPF in relation to the pattern of platelet count was analyzed. The proportion of patients showing platelet recovery at different time points was also determined. A receiver operating characteristic analysis was done to determine an IPF cut-off value predictive of platelet recovery within 24 hours. Results: The IPF increased as the platelet count decreased. The highest increase in IPF coincided with the trough of platelet count. Eighty -seven percent of the patients showed platelet recovery after the increasing trend of IPF, 87% after the peak value and 95% after the decreasing trend. An IPF value of more than 6.6% was found to be predictive of platelet recovery within 24 hours, with a sensitivity of 45% and specificity of 70%. Conclusion: There was an observed inverse relationship between IPF and platelet count but with a statistically weak correlation. The decreasing trend of IPF can be a possible good predictor of an increasing trend in platelet count. These findings suggest a possible role of IPF as an additional parameter to predict platelet recovery in pediatric dengue fever patients.

IMMATURE PLATELET FRACTION (IPF) DAN TROMBOPOIETIN DI SIROSIS HATI

Liver cirrhosis remains a major clinical problem worldwide when associated with significant morbidity and mortality due toits complications. The presence of liver cirrhosis state affects the production of TPO influencing the process of thrombopoiesis. Thethrombopoiesis activity can be described by the Immature Platelet Fraction (IPF) value which is young platelets. The immature Plateletfraction value increases when platelet production enhances as well, on the contrary when the production declines, the IPF value is alsodecreased. This study was performed by cross-sectional method using 31 subject samples suffering from liver cirrhosis, consisting of ChildPugh score class A 2 samples (6.4%), Child Pugh score class B 9 samples (29%) and Child Pugh score class C 20 samples (64.6%). Theexamination of TPO levels was done by ELISA method using Humans TPO QuantikineR, the IPF value was examined using Sysmex XE-2100 Hematology Analyzer. The thrombopoietin serum levels in the samples ranged from 23.5 to 96.6 pg/mL with a mean of 45.1pg/mL.The immature Platelet Fraction values varied from 1.7% to 19.1% with a mean of 6.7%. From the statistical analysis, the levels of TPO andIPF at various degrees of the disease severity were not significantly different. There was no significant correlation between the TPO leveland IPF value, r = 0.038, p = 0.837. There was no significant difference between the TPO level and the IPF value in the splenomegaly andnonsplenomegaly state. In conclusion, based on this study no significant correlation was found between the IPF value with thrombopoietinserum levels, as well as the IPF and thrombopoietin levels, and there was no association with the disease severity.

Reference interval for immature platelet fraction on Sysmex XN haematology analyser in adult population.

IntroductionThe Sysmex XN-series haematology analyser has newly adopted a fluorescent channel to measure immature platelet fraction (IPF). To promote the clinical utility of this promising parameter, establishing a reliable reference interval is mandatory. According to previous studies, IPF values may be affected by the employed analyser and the ethnic background of the individual, but no differences seem to be found between individuals’ genders. Therefore, this study aimed to define the reference interval for IPF in a Spanish population following Clinical and Laboratory Standard Institute (CLSI) guidelines.Materials and methodsA total of 153 healthy Caucasian adults from Spain met the inclusion criteria. IPF measurement was performed by means of a Sysmex XN-2000 haematology analyser. A non-parametric percentile method was used to calculate the reference intervals in accordance with CLSI guidelines.ResultsThe obtained reference interval for IPF on the Sysmex XN-2000 was 1.6–9.6% (90% confidence intervals (CIs) were 1.5–1.8 and 9.3–11.5, respectively). No significant gender difference in IPF reference intervals was observed (P = 0.101).ConclusionsThis study provides, for the first time, a reference interval for IPF using a Sysmex XN-2000 in a Spanish population, ranging from 1.6 to 9.6%. These data are needed to evaluate platelet production in several conditions such as thrombocytopenia, inflammatory states and cardiovascular diseases, as well as for future research.

Effects of Analyzer Detection Method, Ethnicity, and Reference Individuals on Reference Interval of Immature Platelet Fraction.

Immature platelet fraction (IPF) is a new biomarker for thrombopoiesis and inflammation. However, the reference interval (RI) is wildly discrepant among published reports. This study aimed to establish the RI of IPF for a population in Taiwan and evaluate the effects the detection method of the analyzer, ethnicity, and reference individuals have on the RI of IPF. The RI of absolute IPF (A-IPF) and IPF% were established with healthy subjects from the outpatient services of the Health Management Department of Taichung Veterans General Hospital between January 1, 2015 and March 1, 2016. These values were used along with published reports for meta-analysis. A-IPF (109/L) and IPF% of Taiwanese were 6.9 - 7.6 and 3.1 - 3.4, respectively. Significant differences were found when performing paired comparisons of the RI of A-IPF and IPF% published in reports. For A-IPF, there was only one paired comparison with a significant difference (Z > 1.96) across 6 reports. Thus, the contribution of the factors examined on the RI of IPF cannot be determined. For IPF%, there were 8 paired comparisons with significant differences across 10 reports. The discrepancy rates of RI for IPF% were 41.2%, 50.0%, and 25.0% with the difference of reference individuals, the analyzer method, and ethnicity, respectively. The RIs of Taiwanese for A-IPF and IPF% were established. Furthermore, the analyzer detection method and the reference individuals contribute to the discrepancy of the RI for IPF% and should be considered cautiously when the value of IPF is interpreted.

Evaluation of bone marrow function with immature platelet fraction in normal pregnancy.

Bone marrow function in pregnancy is influencing blood cell concentration of platelets. The steady state of consumption, recovery and production of platelets is essential for coagulation and bleeding prevention. Reticulated platelets are an intermediate form of thrombocytes during thrombopoiesis representing platelet production. The immature platelet fraction (IPF) represents these platelets as percentage of all thrombocytes. Until now, there is little knowledge on IPF during pregnancy. 69 healthy pregnant women were included in this monocentric study. Serial blood samples of 27 women (study group 1) and single blood samples of 42 women (study group 2) were taken between 20 and 40weeks of gestation. IPF levels and thrombocytes were quantified by a routine clinical hematology analyzer. Both two study groups were analyzed separately. IPF levels increased between 20 and 40weeks of gestation in both study groups. Median absolute values of IPF increased from 8.1/nl to 13.6/nl in study group 1 and remained constant in study group 2. Values in percent rose from 3.63% to 6.06% in study group 1 and from 4.9% to 6.01% in study group 2. Most values stayed below 20/nl or 7-7.5%. Highest IPF levels were measured near term. In contrast, thrombocyte counts decrease slightly during this period. Bone marrow function is mirrored by IPF levels, which increase with gestational age in healthy pregnant women. Most IPF values remain below 20/nl or 7%. More studies are needed to improve understanding of thrombocyte turnover in pregnancy.

Evaluation of the immature platelet fraction contribute to the differential diagnosis of hereditary, immune and other acquired thrombocytopenias

The differential diagnosis of immune (ITP) and hereditary macrothrombocytopenia (HM) is key to patient management. The immature platelet fraction (IPF) represents the subset of circulating platelets with higher RNA content, and has been shown to distinguish hypo- from hyperproliferative thrombocytopenias. Here we evaluated the diagnostic accuracy of IPF in the differential diagnosis between HM and other thrombocytopenias in a population of patients with post-chemotherapy thrombocytopenia (n = 56), bone marrow failure (n = 22), ITP (n = 105) and HM (n = 27). TPO levels were also measured in HM and ITP matched for platelet counts. Platelet counts were similar in all patient groups. Higher IPF values were observed in both ITP (12.3%; 2.4–65.6%) and HM (29.8%; 4.6–65.9%) compared to hypoproliferative thrombocytopenias. IPF values were also higher in HM compared to ITP, yielding a diagnostic accuracy of 0.80 (95%CI 0.70–0.90; P < 0.0001) to distinguish these two conditions. Intra- and inter-assays reproducibility of IPF in HM patients revealed that this is a stable parameter. In conclusion, IPF is increased in HM compared to both ITP and other thrombocytopenias and contributes to the differentiation between ITP and HM. Further studies are warranted to understand the biological rationale of these findings and to its incorporation in diagnostic algorithms of HM.

Immature platelet fraction and the extent of coronary artery disease: A single centre study

Background and aimsImmature platelet fraction (IPF) represents the quote of younger and larger sized circulating platelets, a potential marker of platelet reactivity and major cardiovascular events. We aimed to assess the relationship between IPF levels and the prevalence and extent of coronary artery disease (CAD) in patients undergoing coronary angiography. MethodsA cohort of consecutive patients undergoing coronary angiography in a single centre were included. Significant CAD was defined as at least 1 vessel stenosis >50%, while severe CAD was defined as left main and/or three-vessel disease. IPF levels were measured at admission by routine blood cells count (A Sysmex XE-2100). ResultsWe included 1789 patients, divided according to quartiles values of IPF. IPF levels were directly related to active smoke (p = 0.02), and non-acute coronary syndrome as indication to angiography (p < 0.001), higher levels of haemoglobin and uric acid (p < 0.001, respectively) and lower platelet count (p = 0.003). Angiographic features did not significantly differ according to quartiles values of IPF, but for a lower degree of TIMI flow in patients with a higher percentage of reticulated platelets (p = 0.01) and a higher rate of lesions involving bifurcations (p = 0.05). IPF levels did not affect the prevalence of CAD (77% vs. 82.2% vs. 79.1% vs. 75.6%, p = 0.34, adjusted OR [95% CI] = 0.93 [0.82–1.05], p = 0.22), nor of severe left main/three-vessel CAD (28.5% vs. 34.4% vs. 32.2% vs. 33.1%, p = 0.27; adjusted OR [95% CI] = 0.99 [0.90–1.1], p = 0.88). ConclusionsThe present study shows that among patients undergoing coronary angiography, the immature platelet fraction (IPF) is not associated with the prevalence and extent of coronary artery disease, and, therefore, should not be overlooked as a marker of coronary atherosclerosis.

Immature platelets do not reliably predict platelet recovery in patients with intensive chemotherapy or stem cell transplantation.

It has been reported that immature platelets may indicate imminent platelet (PLT) recovery following intensive chemotherapy and/or haematopoietic stem cell transplantation with the perspective to withhold unnecessary transfusions. The objective of our prospective study was to test immature PLTs as measured by two haematology analysers to predict PLT recovery. This study monitored 51 courses of severe thrombocytopenia after chemotherapy in 35 adult haematology/oncology patients starting at a PLT count <70 × 109 /l until PLT recovery (>20 × 109 /l) or discharge from hospital. Immature platelets as measured by immature platelet fraction (IPF) (Sysmex XE-5000) and retPLT (Abbott CD-Sapphire) as well as reticulocyte and leucocyte count were evaluated regarding their usefulness to predict PLT recovery. Furthermore, the influence of platelet concentrate (PC) transfusions upon IPF and retPLT was assessed. With beginning of thrombocytopenia, most patients demonstrated elevated IPF% (median 8·6%) and retPLT% (median 6·8%). These elevated values significantly dropped after transfusions of PCs. IPF and retPLT values during nadir and at imminent PLT recovery were largely overlapping and receiver operating characteristics analysis demonstrated poor separation between both clinical situations. A reasonable cut-off could not be established to prospectively predict imminent PLT recovery for either of the parameters investigated. Measurements of IPF and retPLT lack predictive power regarding imminent PLT recovery in patients with severe thrombocytopenia following intensive chemotherapy. Decisions regarding prophylactic PC transfusions should not be based on these parameters.

Immature platelet fraction predicts coagulopathy-related platelet consumption and mortality in patients with sepsis

IntroductionThe diagnostic and prognostic value of immature platelet fraction (IPF) in sepsis has not been determined. This study aimed to assess whether IPF is an early predictor of platelet decline due to coagulopathy and is associated with mortality in patients with sepsis. Materials and methodsIn total, 149 patients with a platelet count of ≥80×103/μL on intensive care unit admission (101 with sepsis, 48 controls without sepsis) were prospectively evaluated. We measured IPF on admission and observed for development of subsequent platelet count decline (defined as a >30% decrease or <80×103/μL) in 5days, and mortality at 28days. The absolute immature platelet count (AIPC) was calculated to evaluate thrombopoiesis. ResultsForty-seven patients with sepsis subsequently developed a decrease in platelet count. The IPF was highest in patients whose platelet count decreased, followed by patients without a decrease in platelet count and controls (median, 4.3% [3.1%–8.1%] vs. 3.7% [2.6%–4.6%] vs. 2.1% [1.6%–3.5%], respectively; P<0.0001). The AIPC was similar in patients with and without a decrease in platelet count (7.6 [4.2–10.0] vs. 5.9 [4.2–8.7]×103/μL, respectively; P=0.32). Coagulation derangement was more severe in patients who did than did not subsequently develop a decreased platelet count. Cox regression and receiver operator characteristic curve analysis revealed that IPF was a strong independent predictor of mortality, with accuracy similar to a standard prognostic scoring system. ConclusionsThe admission IPF in septic patients predicts a subsequent decrease in platelet count, indicating platelet consumption with ongoing coagulopathy and risk of poor prognosis.

Immature platelet fraction in Dengue cases

Background: Immature Platelet Fraction (IPF) is an index of thrombopoiesis which quantitates reticulated platelets that have been recently released from the bone marrow. Objectives: To find out the association between the status of immature platelet fraction (IPF) and the recovery of platelets in patients with dengue. Methods & Materials: A prospective study was designed done to find out the association between the status of immature platelet fraction (IPF) and the recovery of platelets in 45 Dengue confirmed (positive NS1 or IgM antibody dengue test) cases whose platelet count was less than one lakh/cumm with or without a downward trend. Platelet count and IPF were estimated using Sysmex XE-2100 (Sysmex, Kobe, Japan). Complete blood count was recorded simultaneously and peripheral smears were studied in all these cases with a note for the presence of large platelets on smear. The cases were managed conservatively. The work was carried out after an approval from Institutional ethics committee. Data was analysed statistically. Results: Among the recovery of platelets, 86.4% showed recovery within 24hrs and the rest with 48 hrs after attaining peak IPF value. A single value IPF more than 10% was indicative of platelet recovery within 24-48 Hours. A positive correlation was observed among immature platelet fraction (IPF) level and the recovery of platelets in those patients with dengue. Conclusion: IPF had a positive correlation with recovery of platelet counts in patients with dengue infections. Hence, Practitioners handling Dengue cases may be oriented to look for IPF, and consider it before referral or active intervention.

Stromal cell-derived factor-1 rs2297630 polymorphism associated with platelet production and treatment response in Chinese patients with chronic immune thrombocytopenia

Stromal cell-derived factor-1 (SDF-1), signaling through CXCR4, is implicated in megakaryopoiesis and platelet production. SDF-1 rs2297630 is a functional polymorphism in linkage disequilibrium with other functional variants in SDF-1. This study aimed to investigate the role of SDF-1 rs2297630 in chronic ITP. The genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism and confirmed by direct sequencing. Immature platelet fraction (IPF) was performed using Sysmex XE-2100. Anti-platelet autoantibodies were assayed by enzyme-linked immunosorbent assay. The main characteristics at diagnosis and the outcome of chronic ITP in 201 Chinese patients were retrospectively reviewed. There was no significant difference in either genotype or allelic distribution between ITP patients and the controls (p = 0.114; p = 0.787). However, both heterozygote (GA) and homozygote minor allele (AA) patients had significantly increased megakaryocyte quantity compared to homozygote genotype (GG) patients at diagnosis (p = 0.011). The mean IPF values of GA and AA genotype patients were higher than those observed in the GG genotype patients when platelet counts ≤50 × 109/L at diagnosis (p = 0.007). Patients with GA and AA genotype showed a higher response rate to standard treatments than patients with GG genotype (p < 0.001). In particular, GA and AA genotype patients had a significantly increased chance of responding to steroids, intravenous immunoglobulin (IVIG), and thrombopoietin analogs (p = 0.007; p = 0.029; p = 0.034, respectively). No significant difference was found between anti-platelet antibodies and genotypes (p = 0.296). In summary, the SDF-1 rs2297630 was associated with platelet production and treatment response in Chinese patients with chronic ITP.

Application of immature platelet fraction absolute immature platelet fraction and thrombelastograph on assessment of bleeding risk in patients with immune thrombocytopenia

目的探讨未成熟血小板比例（IPF）、未成熟血小板绝对值（A-IPF）和血栓弹力图（TEG）在原发免疫性血小板减少症（ITP）患者出血倾向评估中的价值。方法采用ITP-BAT出血评分系统对271例ITP患者进行出血评分及出血程度分级，并行IPF、A-IPF检测，其中125例行TEG检测，分析ITP患者出血程度与IPF、A-IPF、TEG各指标的相关性。结果在271例ITP患者中，不同疾病分期和性别患者的出血程度差异无统计学意义（P>0.05）；儿童以轻度出血为主，与成人出血程度差异有统计学意义（P<0.05）；出血程度和血小板计数呈负相关（P<0.001）。在所有患者、PLT<30×109/L患者以及PLT<30×109/L儿童患者中，血小板计数与IPF呈负相关（P<0.05），与A-IPF、血栓最大幅度（MA）值呈正相关（P<0.05）。在所有患者及PLT<30×109/L患者中，出血程度和IPF呈正相关（P<0.001），与A-IPF、MA值呈负相关（P<0.001）。在PLT<30×109/L儿童患者中，出血程度与IPF、A-IPF、MA值均无相关性（P>0.05）。ROC曲线分析显示IPF、A-IPF、MA值评估ITP患者出血风险效能较好，ROC曲线下面积分别为0.745、0.744、0.813（P<0.001）。多因素分析显示IPF和MA值是预测ITP患者出血倾向的独立因素，综合诊断ROC曲线下面积0.846（P<0.001），优于单一指标。结论IPF、A-IPF和MA值能够准确评估ITP患者的出血风险，可以作为治疗的参考指标和疗效的观察指标。

A time course study of high on treatment platelet reactivity in acute coronary syndrome male patients on dual antiplatelet therapy

IntroductionLimited data are available on the natural history of high on treatment platelet reactivity (HPR) by arachidonic acid and ADP - markers of unfavorable prognosis in acute coronary syndrome patients -. Material and methodsIn a cohort of acute coronary syndrome male patients (n=101), we evaluated the time-course of HPR by ADP (platelet aggregation by 10μM ADP≥70%) and arachidonic acid (platelet aggregation by 1mmol arachidonic acid≥20%) measuring platelet function in the acute phase (T0), at 6months (T1) and 1year (T2). ResultsWe identified persistent (HPR at T0,T1 and T2), acute non persistent (HPR only at T0), and late (HPR only at T1 or T2). Patients with persistent HPR by ADP were more frequently with higher values of BMI. Patients carrying CYP2C19*2 variant were more prevalent in the group of persistent HPR (33%). Significant higher values of immature platelet fraction and high immature platelet fraction at 6 and 12months and mean platelet volume were present in patients with late HPR. Immature platelet fraction was the only variable significantly associated with late HPR by ADP at multivariate analysis (OR=1.6 (1.08-2.3), p=0.016). Patients with persistent HPR by arachidonic acid were more frequently diabetics. Immature platelet fraction at 6months and high immature platelet fraction at 6 and 12months were the parameters associated with late HPR by AA (OR=1.4 (1.0-1.9), p=0.036; OR=1.5 (1.08-2.4), p=0.05; OR=4.9 (1.3-18.8), p=0.018, respectively). ConclusionsAbout 25% of 101 patients has persistent HPR; they are more frequently diabetics, overweight or carriers of CYP2C19*2. The occurrence of an inflammatory state, indicated by the increase of immature platelet fraction, is associated with the occurrence of late HPR.

Immature platelet fraction measurement is influenced by platelet size and is a useful parameter for discrimination of macrothrombocytopenia

BackgroundReticulated platelets (RPs) as measured using flow cytometry are useful parameters of thrombopoiesis; however, difficulties remain with standardization between laboratories. On the other hand, immature platelet fraction (IPF) measurement, as determined using an automated hematology analyzer, is simple, reproducible, and displays a good correlation with RP, although specific factors may affect its value. We previously noticed that a small proportion of patients exhibit extremely high IPF values that do not correlate with flow cytometrically measured RP.ObjectivesWe investigated the mechanism of the aberrant increase in IPF values of different types of macrothrombocytopenia.Patients/methodsIPF, RP, and other platelet indexes were analyzed using samples from 15 congenital macrothrombocytopenic patients from 12 families, 150 immune thrombocytopenic patients, and 27 normal individuals. We further monitored the change in IPF values and morphology during platelet agglutination.ResultsIPF values were about five times higher in MYH9 disorders (IPF 48.6 ± 1.9%) and about twice as high in other macrothrombocytopenias (IPF 18.4 ± 2.1%) than in immune thrombocytopenic patients with similar platelet counts (IPF 9.2 ± 0.3%). We then examined changes in IPF values during ethylenediaminetetraacetic acid- and macroglobulinemia-induced platelet agglutination. The IPF value significantly increased in a time-dependent manner along with the formation of platelet clumps and was strongly influenced by a few tiny platelet aggregates.ConclusionsThese results suggested that IPF values are influenced by platelet size. Furthermore, IPF could be a useful and convenient parameter for screening of macrothrombocytopenia, which presents with a disproportionately high IPF value.

Immature Platelet Fraction Predicts Outcome and Sepsis Development in Critically Ill Patients Admitted to a General Intensive Care Unit, but Not in Neutropenic Patients

Introduction: Immature platelet fraction (IPF) is a new laboratory parameter, representing a fraction of young platelets in peripheral blood count which is known to correlate with thrombopoiesis. IPF can be reported in absolute numbers or expressed as percentage (IPF%) of total platelet count. IPF% can be used to differentiate individuals at higher risk for bleeding among patients suffering from immune thrombocytopenia and to predict recovery of blood counts after stem cell transplantation (SCT). Moreover, IPF% was also reported to predict the development of sepsis in patients admitted to the general intensive care unit. This study was aimed to prospectively evaluate the value of IPF% as a predictor of clinical outcome and/or mortality in patients susceptible to sepsis.Methods: Two different patient populations at high risk for life-threatening infection, i.e., patients presenting with fever and neutropenia and adults admitted to the general intensive care unit (ICU) of a tertiary health care center for various reasons apart from neutropenic fever were prospectively studied. IPF was measured using the Sysmex XE-2100 analyzer during the first 24 hours of hospitalization. In addition, C-reactive protein (CRP) and Interleukin-6 (IL-6) levels were tested in some of the patients. All patients were monitored and their vital signs, renal function, hemodynamic and respiratory state, as well as final outcome were recorded. For patients with neutropenic fever, the infectious pathogen was listed, whenever identified. Treating physicians were blinded to IPF% results to ensure that clinical decisions were not affected by consideration of this parameter.Results: One hundred and four adults with neutropenic fever and 138 additional adults admitted to the ICU were included in the study.A median age of patients admitted to ICU and those with neutropenic fever was 53 (range 17-88) and 55 (range 18-85) years; males composed 58% and 60% of the cohorts, respectively. A mean IPF% in patients admitted to ICU was significantly higher than that determined in neutropenic patients (8.6 vs 6.8). IPF% levels during the first 24 hours of admission, predicted mortality (p = 0.037) for patients admitted to ICU but not for patients presenting with neutropenic fever. In patients admitted to ICU, high IPF% was also associated with length of stay in the unit, poor hemodynamic status, and death. Neither IL-6 plasma level nor CRP correlated with these clinical outcomes. APACHE-II score (a known disease severity scale in ICU patients) and IPF% were not correlated by Pearson test (p=0.09).Conclusion: IPF% is a valuable biomarker for predicting prognosis in ICU patients independent of APACHE-II score. This study suggests that the validity of IPF% as a predictor of outcome depends on the bone marrow (BM) capacity. In patients with normal bone marrow admitted to ICU, IPF% correlates with the significance of stress and severity of the disease. In patients presenting with neutropenic fever, BM reserve is impaired due to chemotherapy. Larger studies are needed to evaluate the role of IPF% in different patient populations and to determine its application to patients with impaired BM reserves such as immunocompromised patients and those at older age. DisclosuresNo relevant conflicts of interest to declare.

Evaluation of the immature platelet fraction in the diagnosis and prognosis of childhood immune thrombocytopenia

Rapid assessment of platelet production would distinguish between thrombocytopenia due to decreased platelet production or increased peripheral platelet destruction. We evaluated the value of immature platelet fraction (IPF) in differentiating immune thrombocytopenia (ITP) from thrombocytopenia secondary to bone marrow failure and its potential use as a prognostic marker. Forty-one young patients with ITP were compared with 14 patients with hematological malignancies under chemotherapy, representing a control group with thrombocytopenia due to bone marrow suppression and 30 age- and sex-matched healthy controls. Patients were studied stressing on bleeding manifestations, organomegaly/lymphadenopathy and therapy. Complete blood count including IPF was performed using Sysmex XE-2100. ITP patients were classified into two subgroups: acute ITP with spontaneous resolution within 3 months from diagnosis and chronic ITP that lasted ≥1 year from diagnosis. Median IPF was 11.8% in patients with ITP, 7% in those with hematological malignancy and 3% in the control group (p < 0.001). ITP patients had significantly higher mean platelet volume (MPV), platelet distribution width (PDW), platelet large cell ratio (P-LCR) and IPF compared with patients with malignancy or healthy controls, while plateletcrit (PCT) was significantly lower in ITP patients than other groups (p < 0.001). IPF was increased in patients with chronic ITP compared with acute ITP group (p < 0.001). Patients with active ITP had the highest IPF followed by those in partial remission, while ITP patients in remission had the lowest IPF. IPF was positively correlated to the number of lines of treatment used, MPV, PDW and P-LCR, while negatively correlated to platelet count and PCT among ITP patients (p < 0.001). Multiple regression analysis showed that platelet count and P-LCR were independently related to IPF. ROC curve analysis revealed that the cut-off value of IPF at 9.4% could be diagnostic for ITP patients with a sensitivity of 88% and a specificity of 85.7%. We suggest that IPF may be a rapid and inexpensive automated marker for etiology of thrombocytopenia and can be integrated as a standard parameter to evaluate the thrombopoietic state of the bone marrow. It may be considered as a potential prognostic marker for the development of chronic ITP.

Increased mean platelet volume and immature platelet fraction as potential predictors of thrombotic complications in BCR/ABL-negative myeloproliferative neoplasms.

BCR/ABL-negative myeloproliferative neoplasms (MPNs) are considered to be acquired thrombophilic conditions. Persistently enhanced platelet activation has been described in polycythaemia vera and essential thrombocythaemia (ET), and shown to contribute to a higher risk of arterial and venous thrombotic complications. Recent studies have shown that mean platelet volume (MPV) and immature platelet fraction (IPF) can serve as useful markers of platelet activation and increased risk of thrombosis. The aim of the present study was to investigate the relationship between these parameters and thrombotic events in BCR/ABL-negative MPN. MPV values in patients with BCR/ABL-negative MPN were significantly higher than MPV values of healthy individuals (P<0.001). No significant difference in MPV or IPF was observed between groups of patients with and without thrombotic complications (P=0.441; P=0.110); the difference in IPF values was close to the significance level for patients with ET (P=0.073). Higher values of IPF were more frequently detected in patients with JAK2 V617F positivity (P=0.030). These patients had higher MPV more frequently than others, and this difference was close to the significance level (P=0.056). Further studies should validate the use of platelet parameters to identify patients at high risk.

Evaluation of the immature platelet fraction as an indicator of platelet recovery in dengue patients.

Thrombocytopenia is a common complication in many disorders (such as aplastic anemia, ITP, dengue fever,), the etiology being multifactorial. Immature platelet fraction (IPF) is a new parameter which is a measure of reticulated platelets that reflects the rate of thrombopoiesis. We tried to evaluate IPF as an indicator to predict the recovery of platelets in patients with dengue. A total of 32 patients suffering from dengue fever (as confirmed by NS1 antigen or IgM antibody positivity for dengue) were taken for the study. The platelet count and IPF value of all these patients were evaluated on a daily basis. It was found out that IPF has a strong correlation with the recovery of platelet counts in patients with dengue. 84.3% patients showed recovery within 24 h after attaining the peak IPF, 93.75% of the patients showed recovery within 24-48 h of the rise of the IPF compared with the previous day's value, and 100% patients showed a recovery within 24 h of the fall of the IPF compared with the previous days. It was also observed that 93.75% of the patients show platelet recovery within 24-48 h if the IPF was more than 10%. Based on our study, we concluded that IPF can be used to evaluate the recovery of platelets in patients with dengue. It holds a great promise of becoming a reliable future guide for decisions concerning platelet transfusions.

Moving Average Of Immature Platelet Fraction Predict Late Platelet Engraftment After Reduced-Intensity Cord Blood Transplantation: A Single-Institutional Study

Introduction Platelet engraftment is an important marker of successful allogeneic stem cell transplantation and platelet is the last to be regenerated in bone marrow after stem cell transplantation. Especially, platelet engraftment is far slower in reduced-intensity conditioning regimen(RIC) in cord blood transplant(CBT). Early prediction of platelet engraftment in RIC-CBT can be helpful to proper treatment. Recent retrospective studies suggested immature platelet fraction(IPF) can be useful to predict platelet engraftment. However, the role of IPF in RIC-CBT is not be sufficiently investigated. In addition, these studies included patients undergoing bone marrow or peripheral blood transplantation. Therefore, we analyzed cases in our database to evaluate the impact of IPF and Reticulocyte count(RET%) on the outcome of platelet engraftment in consecutive patients who were treated with RIC-CBT over the past 4 years at our institution in Tokyo, Japan. Patients and Methods We included 53 consecutive patients treated at our institution between April 2008 and May 2013. The study population consisted of 29 male and 23 female patients with a median age of 57 years old (range: 36-69). Patient in this cohort underwent RIC-CBT as a part of therapy for myeloid malignancies(N=28) and lymphoid malignancies (N=24). 21 patients were treated with Flu+Cy+TBI(2gy), and 31 patients were treated with Flu+Bu+TBI(2Gy). All patients received calcineurin inhibitor plus MMF for GVHD prophylaxis. Due to the influence of blood transfusion on IPF and RET% and overall estimation of IPF and RET% movement, IPF and RET% were assessed by using the 5-day moving average ,and then we compared movement of the fifth moving average between patients with platelet engraftment and patients without platelet engraftment. The fifth moving average was calculated from the time of day4 after transplantation until the date of platelet engraftment or death from any cause or the date on which the patient was received next chemotherapy. Platelet engraftment was defined as independent from platelet transfusion. Result Among 53 patient, 29 patieunt achieved platelet engraftment. The median time of platelet engraftment was day +42 (range:24-203day), and median time of follow up periods of patients without platelet engraftment was 47 days. 16 patients achieved platelet engraftment after day +40. Baseline characteristics according to patients who achieved platelet engraftment, or did not achieve were similar among RIC-regimen, patient diagnosis. Patients' age, sex, total cell count andCD34 cell count in donor cord blood has no impact on pletelet engraftment. Maximum value of IPF did not have significant impact on platelet engrafment. As shown figure 1, The mean of the 5-day moveing average in IPF show similar curve from day +4 to day +30 between patient with platelet engraftment and without, and after +30 days the curve of patient with platelet engraftment gradually highter than the curve of patient without platelet engraftment. The difference of these curves was larger after day +50. In the RET% case, it was almost same. the 5-day moveing average of IPF and RET% in platelet engraftment patient were raising after day +40, while those in non-engraftment patient were decreasing in this period. Provided the 5-day moving average of IPF are blow 6.0 from day +40 to day +50, It is highly likely that platelet engraftment can't be expected (p=0.001 in univariate analyses). Likewise, provided the 5-day moving average RET% are blow 1.5 from day +40 to day +50, platelet engraftment significantly can't be expected (p=0.002). Conclusion The results of the present study highlighted the importance of the fifth-moving average of IPF and RET% after day +40, and IPF and RET% can be useful tools to predict platelet engraftment in RIC-CBT. Disclosures: No relevant conflicts of interest to declare.