Medicine
Contributions
Type: Publication Only
Background
Immature platelets are newly released reticulated platelets into circulation. They can be measured using a specifically designed automated hematology analyzer as immature platelet fraction (IPF). IPF was shown to be high in immune thrombocytopenic purpura (ITP) due to rapid clearance and enhanced production of platelet. In aplastic anemia (AA), IPF was lower because of low platelet production rate. Utilization of this parameter to differentiate causes of thrombocytopenia between underproduction and peripheral destruction has been proposed. There is no IPF data on other diseases with similar mechanisms such as hypersplenism, Evans syndrome (ES), thrombotic thrombocytopenic purpura (TTP), or chemotherapy-induced bone marrow suppression (CIBMS).
Aims
To measure IPF in healthy Thai volunteers, and patients with thrombocytopenia from various causes and to compare IPF from different thrombocytopenic mechanisms i.e. underproduction (AA, CIBMS) and peripheral destruction/ sequestration (ITP, TTP, ES, hypersplenism).
Methods
This was a prospective, cross-sectional, observational study. Each EDTA-anticoagulated blood from Thai healthy volunteers (NL; 51) and thrombocytopenic patients (67) (platelet count < 150 x 109/L) with known diagnosis of AA (14), CIBMS (22), ITP (20), TTP (2), ES (3) and hypersplenism (6) was analyzed by Sysmex XE-5000 for complete blood count, reticulocyte parameters (percentage, absolute count and fluorescent ratio), IPF, and mean platelet volume (MPV). Peripheral blood smears were simultaneously examined for RBC, WBC and platelet morphology. Clinical parameters were collected on fever, anemia, jaundice, bleeding status with/ without ecchymosis, and concurrent therapy for thrombocytopenia.
Results
Mean platelet number (x 109/L) for NL, AA, CIBMS, ITP, TTP, ES and hypersplenism were 277.25, 27.21, 35.55, 50.20, 54.50, 22.67, and 63, respectively. Negative correlation between platelet number and IPF value was shown in which the lowest median IPF (%) was found in NL (1.50; 0.6-4.5) compared among underproduction (2.95; 0.7-24.8) and peripheral destruction group (4.80; 0.2-25.7). In each underproduction subgroup, median IPFs (%) for AA and CIBMS were 4.25 (1.8-24.8) and 2.50 (0.7-15.5). In each peripheral destruction/ sequestration subgroup, median IPFs (%) were 5.45 (0.2-25.7), 4.90 (2.4-7.4), 8.90 (4.8-11.4), and 3.95 (1.3-17.2) for ITP, TTP, ES and hypersplenism, respectively. A cut-off absolute immature platelet count value of more than 1,000 x 109/L was proposed to differentiate peripheral destruction from underproduction mechanism with sensitivity and specificity of 75.2 % and 63.9 %, respectively.
Summary
IPF is a simple, reliable parameter and can potentially be used to differentiate mechanisms causing thrombocytopenia. More beneficial roles of IPF are expected.
Keyword(s): Immune thrombocytopenia (ITP), Thrombocytopenia
Type: Publication Only
Background
Immature platelets are newly released reticulated platelets into circulation. They can be measured using a specifically designed automated hematology analyzer as immature platelet fraction (IPF). IPF was shown to be high in immune thrombocytopenic purpura (ITP) due to rapid clearance and enhanced production of platelet. In aplastic anemia (AA), IPF was lower because of low platelet production rate. Utilization of this parameter to differentiate causes of thrombocytopenia between underproduction and peripheral destruction has been proposed. There is no IPF data on other diseases with similar mechanisms such as hypersplenism, Evans syndrome (ES), thrombotic thrombocytopenic purpura (TTP), or chemotherapy-induced bone marrow suppression (CIBMS).
Aims
To measure IPF in healthy Thai volunteers, and patients with thrombocytopenia from various causes and to compare IPF from different thrombocytopenic mechanisms i.e. underproduction (AA, CIBMS) and peripheral destruction/ sequestration (ITP, TTP, ES, hypersplenism).
Methods
This was a prospective, cross-sectional, observational study. Each EDTA-anticoagulated blood from Thai healthy volunteers (NL; 51) and thrombocytopenic patients (67) (platelet count < 150 x 109/L) with known diagnosis of AA (14), CIBMS (22), ITP (20), TTP (2), ES (3) and hypersplenism (6) was analyzed by Sysmex XE-5000 for complete blood count, reticulocyte parameters (percentage, absolute count and fluorescent ratio), IPF, and mean platelet volume (MPV). Peripheral blood smears were simultaneously examined for RBC, WBC and platelet morphology. Clinical parameters were collected on fever, anemia, jaundice, bleeding status with/ without ecchymosis, and concurrent therapy for thrombocytopenia.
Results
Mean platelet number (x 109/L) for NL, AA, CIBMS, ITP, TTP, ES and hypersplenism were 277.25, 27.21, 35.55, 50.20, 54.50, 22.67, and 63, respectively. Negative correlation between platelet number and IPF value was shown in which the lowest median IPF (%) was found in NL (1.50; 0.6-4.5) compared among underproduction (2.95; 0.7-24.8) and peripheral destruction group (4.80; 0.2-25.7). In each underproduction subgroup, median IPFs (%) for AA and CIBMS were 4.25 (1.8-24.8) and 2.50 (0.7-15.5). In each peripheral destruction/ sequestration subgroup, median IPFs (%) were 5.45 (0.2-25.7), 4.90 (2.4-7.4), 8.90 (4.8-11.4), and 3.95 (1.3-17.2) for ITP, TTP, ES and hypersplenism, respectively. A cut-off absolute immature platelet count value of more than 1,000 x 109/L was proposed to differentiate peripheral destruction from underproduction mechanism with sensitivity and specificity of 75.2 % and 63.9 %, respectively.
Summary
IPF is a simple, reliable parameter and can potentially be used to differentiate mechanisms causing thrombocytopenia. More beneficial roles of IPF are expected.
Keyword(s): Immune thrombocytopenia (ITP), Thrombocytopenia