Diagnostic characteristics of immature platelet fraction for the assessment of immune thrombocytopenia.

The diagnosis of immune thrombocytopenia (ITP) remains an exclusion, as a specific biomarker is missing. We aimed to investigate the diagnostic characteristics, establish a cut-off point for reticulated platelets, and compare it with the clinical exclusion diagnosis used in the assessment of ITP. Forty-one patients with ITP and 187 healthy individuals were enrolled in Santa Maria, Brazil. Sysmex XE-5000 was used to measure IPF. We obtained an IPF cut-off point of 6.3% with a sensitivity of 92.7% (95% CI: 80.1-98.5) and a specificity of 92.5% (95% CI: 87.8-95.8). The area under the curve was 0.97. The kappa coefficient was 0.85 (95% CI: 0.75-0.95), which shows high agreement between methods. The positive (PPV) and negative predictive values (NPV) were 81.25% and 96.42%, respectively. From the cut-off point, kappa index, PPV, and NPV obtained, it is possible to conclude that IPF can be an efficient laboratory marker for diagnosing ITP.

Mean Platelet Volume and Immature Platelet Fraction in Autoimmune Disorders.

Mean platelet volume (MPV), measured using automated blood analysers, has been appraised as a potential biomarker in cardiovascular disease, diabetes mellitus, and cancer. The test, a useful tool in differentiation of thrombocytopenic states, has now been carried out for autoimmune disorders, but data are yet scarce. Controversial results have been obtained in systemic and organ-specific autoimmune disorders. Another test, the immature platelet fraction (IPF) reflects the amount of young, reticulated platelets. IPF is calculated by automated hematology analysis or flow cytometry, and it is usually high in patients with rapid platelet destruction. For both MPV and IPF, standardization of cutoff is a major need. In this review, we focus the current applicability of MPV and IPF as biomarkers in patients with autoimmune diseases.

Determination of reference ranges for immature platelet and reticulocyte fractions and reticulocyte hemoglobin equivalent

ABSTRACT Introduction: The immature platelet and immature reticulocyte fractions represent the ratios of platelets and reticulocytes recently released into the circulation and thus with higher RNA content. They are considered early indicators of bone marrow recovery. Objective: The aim of this study was to determine the reference ranges for the immature platelet and reticulocyte fractions of hematologically normal individuals in a university hospital. Methods: Venous blood samples collected in ethylenediaminetetraacetic acid K3 were analyzed using a Sysmex XE-5000™ analyzer. Individuals with platelet and reticulocyte counts within the reference ranges, and a blood count within the laboratory's screening criteria were included. Individuals with clinical conditions that could affect hematological results were excluded. The immature platelet fraction, high, medium and low fluorescence reticulocyte fractions and reticulocyte hemoglobin equivalent were evaluated. The reference ranges were determined according to the recommendations of the International Federation of Clinical Chemistry. Results: One hundred and thirty-two outpatients were evaluated. The mean age was 44 years (range: 13-80 years), 72 (54.5%) were women treated in a university hospital. The mean platelet count was 250.8 × 109/L and the mean reticulocyte count was 0.052 × 109/L. The following reference ranges were obtained: immature reticulocyte fraction 1.6-12.1%, the high, medium and low fluorescence reticulocyte fractions were 0.0-1.7%, 1.6-11.0% and 87.9-98.4%, respectively, the reticulocyte hemoglobin equivalent was 30.0-37.6% and immature platelet fraction was 0.8-5.6%. There was a statistically significant difference (p-value = 0.006) between genders in respect to the immature platelet fraction with 0.8-4.7% for females and 0.7-6.1% for males. The immature reticulocyte fraction was directly correlated with the reticulocyte count. Conclusion: Determining the reference range is critical to the introduction of a new parameter. The reference ranges obtained herein corroborate those reported in previous publications and will contribute to the clinical and laboratory application of the indices.

Determination of reference ranges for immature platelet and reticulocyte fractions and reticulocyte hemoglobin equivalent.

INTRODUCTION: The immature platelet and immature reticulocyte fractions represent the ratios of platelets and reticulocytes recently released into the circulation and thus with higher RNA content. They are considered early indicators of bone marrow recovery. OBJECTIVE: The aim of this study was to determine the reference ranges for the immature platelet and reticulocyte fractions of hematologically normal individuals in a university hospital. METHODS: Venous blood samples collected in ethylenediaminetetraacetic acid K3 were analyzed using a Sysmex XE-5000™ analyzer. Individuals with platelet and reticulocyte counts within the reference ranges, and a blood count within the laboratory's screening criteria were included. Individuals with clinical conditions that could affect hematological results were excluded. The immature platelet fraction, high, medium and low fluorescence reticulocyte fractions and reticulocyte hemoglobin equivalent were evaluated. The reference ranges were determined according to the recommendations of the International Federation of Clinical Chemistry. RESULTS: One hundred and thirty-two outpatients were evaluated. The mean age was 44 years (range: 13-80 years), 72 (54.5%) were women treated in a university hospital. The mean platelet count was 250.8×109/L and the mean reticulocyte count was 0.052×109/L. The following reference ranges were obtained: immature reticulocyte fraction 1.6-12.1%, the high, medium and low fluorescence reticulocyte fractions were 0.0-1.7%, 1.6-11.0% and 87.9-98.4%, respectively, the reticulocyte hemoglobin equivalent was 30.0-37.6% and immature platelet fraction was 0.8-5.6%. There was a statistically significant difference (p-value=0.006) between genders in respect to the immature platelet fraction with 0.8-4.7% for females and 0.7-6.1% for males. The immature reticulocyte fraction was directly correlated with the reticulocyte count. CONCLUSION: Determining the reference range is critical to the introduction of a new parameter. The reference ranges obtained herein corroborate those reported in previous publications and will contribute to the clinical and laboratory application of the indices.

Assessment of immature platelet fraction and immature reticulocyte fraction as predictors of engraftment after hematopoietic stem cell transplantation.

INTRODUCTION: Engraftment is a critical milestone of the hematopoietic stem cell transplantation (HSCT) process. The immature platelet fraction (IPF) and immature reticulocyte fraction (IRF) are considered early indicators of bone marrow recovery. The objective of this study was to assess these parameters as predictors of HSCT engraftment. METHODS: Neutrophil and platelet engraftment were defined as the first of three consecutive days with an absolute neutrophil count >0.5 × 10(9) /L or platelet count >20 × 10(9) /L, respectively. The IRF cutoff was 12%. Two IPF cutoffs were used: >6.2% and >10%. RESULTS: The study sample comprised 44 patients, of whom 24 had undergone autologous HSCT and 20 had undergone allogeneic HSCT. Absolute neutrophil counts >0.5 × 10(9) /L were preceded by IRF >12% in 86% of patients (38 of 44). Platelet counts >20 × 10(9) /L were preceded by an IPF >6.2% in 90% of patients (37 of 41) and by an IPF >10% in 63% of patients (26 of 41). CONCLUSION: The results show that IRF and IPF are engraftment predictors. Peak in IPF was observed before rise in platelet count, while IRF rises before absolute neutrophil count (ANC) and persists increased. This indicates that IRF and IPF can be considered as new tools for hematopoietic assessment after HSCT.