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PubMed2003

Impact of pretreatment thrombocytosis on survival in primary breast cancer.

Platelet count has been reported to have predictive value in various cancer entities. In the case of breast cancer, evidence about involvement of platelets is still incomplete. Our objective was to assess the influence of pretreatment thrombocytosis on survival and establish its prognostic relevance for breast cancer patients. We performed a retrospective, multivariate analysis of 4,300 patients with early-stage breast cancer. All subjects participated in one of five prospective, randomized, multicenter trials conducted by the Austrian Breast and Colorectal Cancer Study Group. Thrombocytosis was defined as a platelet count exceeding 400 G/L. Median follow-up was 52 months. Univariate and multiple Cox regression models were calculated for overall survival (OS), breast cancer-related survival and disease-free survival (DFS). Pretreatment thrombocytosis was observed in 161 patients (3.7%). Estimated median OS, breast cancer-related survival and DFS for patients with versus those without thrombocytosis was 71.0 versus 99.5, 72.0 versus 100.9, and 80.4 versus 88.4 months, respectively (p = 0.0054, p = 0.0095, p = 0.0199). A multiple Cox regression model including tumor and nodal status, grading, age, hormone receptor status and pretreatment thrombocytosis identified pretreatment thrombocytosis as an independent predictive factor for OS (p = 0.0064) and breast cancer-related survival (p = 0.0162). Multivariate analysis failed to identify pretreatment thrombocytosis as an independent risk factor for DFS (p = 0.1355). In our retrospective study, elevated platelet counts at time of diagnosis were associated with poor prognosis in breast cancer. We hypothesize that platelets may contribute to the pathophysiology of hematogenous metastasis.

Aged↗
PubMed2004

[Report of 8 cases of bcr-abl gene positive thrombocytosis and review of the literature].

OBJECTIVE: To analyse the features of 8 cases of Bcr(+) thrombocytosis. METHODS: The clinical and hematological features and therapeutic outcomes were studied retrospectively in 8 Bcr(+) thrombocytosis and compared with essential thrombocytosis (ET) and chronic myeloid leukemia-chronic phase thrombocytosis (CML-CP-T). BCR-ABL fusion gene was detected with PCR. RESULTS: (1) Except for the presence of BCR-ABL fusion gene, there was no significant difference in clinical and hematological features and therapeutic outcomes between thrombocytosis with or without BCR-ABL. (2) The Bcr(+) thrombocytosis differed from CML-CP-T in the following aspects: female predominance, milder or no splenomegaly, peripheral leukocytes count < 40 x 10(9)/L, less or no basophilia and fewer immature granulocytes in peripheral blood, bone marrow granulocytic and/or megakaryocytic lineage hyperplasia, normal or increased neutrophil alkaline phosphatase score and less blastic transformation. CONCLUSION: Bcr(+) thrombocytosis may be considered as a new member of chronic myeloproliferative diseases, a variant of essential thrombocythemia.

Adult↗
PubMed1990

Prolonged thrombocytosis in mice after 5-fluorouracil results from failure to down-regulate megakaryocyte concentration. An experimental model that dissociates regulation of megakaryocyte size and DNA content from megakaryocyte concentration.

Rodents treated with 150 mg/kg of 5-fluorouracil (5-FU) exhibit a marked and prolonged rebound thrombocytosis, suggesting that feedback control of one or more megakaryocyte characteristics (size, polyploidy, or concentration) is altered. To determine the changes in megakaryocytes that lead to such a profound thrombocytosis, C3H mice were injected with 150 mg/kg 5-FU, and platelet and megakaryocyte responses were examined at frequent intervals from days 1 through 25. After 5-FU injection, all megakaryocyte indices decreased, as did platelet number. However, the decrease in platelets to one third of control was greater than the decreases in megakaryocyte indices, suggesting that thrombocytopoiesis was ineffective from days 3 through 7 post 5-FU. Megakaryocyte size began to recover on day 4, followed by polyploid DNA content on day 5, and megakaryocyte concentration and platelets at 7.5 days. Megakaryocyte size peaked on days 6 through 8 (1.25 x normal), followed by megakaryocyte polyploid DNA content on day 8, megakaryocyte concentration on days 9 through 12 (2 1/2 to 3x normal), and platelets on days 12 through 15 (2x normal). Platelet levels are thought to be important in the feedback regulation of megakaryocytes; however, only polyploid DNA content distributions showed a close inverse relationship to platelet counts during both the recovery and rebound thrombocytosis phases after 5-FU. In contrast, megakaryocyte size peaked before platelet recovery commenced, while megakaryocyte concentration increased in parallel with platelets from 7.5 to 10 days post 5-FU and continued to be maintained at 2 to 3 times normal through day 13, despite platelet levels that were more than twice normal. Both megakaryocyte size and polyploid DNA content distributions shifted toward lower values in response to the rebound thrombocytosis (DNA content on day 10 and size on days 12 and 13). Splenectomy did not substantially alter the pattern of post 5-FU rebound thrombocytosis or megakaryocyte response from that seen in intact mice, indicating that splenic megakaryocytes are not responsible for the prolonged thrombocytosis seen after this drug. In summary, the prolonged thrombocytosis after 5-FU administration results from failure to down-regulate the number of precursors entering the differentiating megakaryocyte compartment. These data indicate that megakaryocyte size and DNA content are responsive to different feedback controls than megakaryocyte concentration in this model system.

Animals↗
PubMed1998

Ovarian carcinoma associated thrombocytosis. Correlation with prognostic factors and with survival.

OBJECTIVE: To assess the prevalence of thrombocytosis (platelets > or = 400,000 microliters) in ovarian cancer of epithelial origin as compared to benign controls consisting of benign ovarian cysts of epithelial origin and to correlate it with prognostic factors of ovarian cancer and survival. METHOD: Hospital records of 82 consecutive patients with ovarian carcinoma, 12 with low malignant potential tumors and 70 with invasive carcinoma, and of 32 patients with benign cysts of epithelial origin were reviewed. The clinical data and preoperative platelet counts were recorded. RESULTS: The prevalence of thrombocytosis in invasive ovarian carcinoma of epithelial origin was significantly higher than in benign controls (24.3% vs 2.9%; p = 0.006). No statistically significant correlation was found between thrombocytosis with age, grade and residual disease. A statistically non-significant excess of thrombocytosis was found among patients with advanced disease, but the survival of patients with thrombocytosis was significantly less favorable (p = 0.04). CONCLUSIONS: Thrombocytosis is significantly more prevalent in ovarian cancer patients than in benign controls and has a statistically significant correlation with poorer survival. The prevalence of thrombocytosis in ovarian carcinoma and its significance in various studies is inconsistent and should be elucidated in large prospective studies.

Adolescent↗
PubMed1990

Thrombocytosis in young people: evaluation of 57 cases diagnosed before the age of 40.

Over the past 13 years 57 cases of primary thrombocytosis in young people have been studied. Only patients with a platelet count over 500 x 10(9)/liter and a follow-up longer than 2 years were considered. Thrombocytosis in young people represents approximately 25% of total cases referred to our department during this period. The most common causes are essential thrombocythemia (20 cases) and secondary thrombocytosis (22 cases). The highest platelet counts are found in essential thrombocythemia patients. Most of our patients were discovered by a fortuitous hematological examination. In contrast, 5 out of the polycythemic patients were recognized after a thrombosis. The same was true for 2 out of 20 essential thrombocythemia subjects. Four subjects (2 essential thrombocythemia and 2 secondary thrombocytosis) were diagnosed after hemorrhages. The overall survival was very good except for leukemic patients and thrombocytosis secondary to neoplasms. Vascular complications after diagnosis were scarce: 2 polycythemia vera patients showed bleedings during antiaggregating therapy. None of our patients developed epithelial cancer, malignant lymphoma or myelofibrosis. Vascular traumata seem more frequent in polycythemia vera regardless of age. Therefore, it seems useful to treat polycythemic patients, while no therapy seems to be indicated in other forms of thrombocytosis.

Adult↗
PubMed2002

Poor prognosis associated with thrombocytosis in patients with gastric cancer.

BACKGROUND: Thrombocytosis is commonly associated with malignant disease and has recently been suggested to be a poor prognostic indicator in patients with lung cancer and gynecological cancers. The prevalence of thrombocytosis in patients with gastric cancer was reviewed, and its association with poor prognosis was investigated. METHODS: Platelet count (PLT) and hemoglobin concentrations (Hb) were reviewed in 369 consecutive patients with histologically verified gastric cancer from 1994 to 2000. Differences between categories were analyzed with analysis of variance, and survival was compared by using the log-rank test on the Kaplan-Meier life table. Multivariate Cox regression analysis was used to evaluate whether thrombocytosis is an independent prognostic marker. RESULTS: Thrombocytosis was found in 42 patients, and anemia was found in 200 patients. PLT was negatively correlated with Hb. Mean PLT was significantly increased in patients with noncurative operations. There was a positive correlation between the depth of tumor invasion and PLT. One- and 3-year survival expectancies in patients with or without thrombocytosis were 52.4% and 23.4% and 85.7% and 72.9%, respectively. PLT was identified as an independent prognostic factor after lymph node metastasis and depth of tumor invasion. CONCLUSIONS: Thrombocytosis is an independent prognostic indicator of survival in patients with gastric cancer.

Adult↗
PubMed1998

Thrombopoietin serum concentration in patients with reactive and myeloproliferative thrombocytosis.

We wished to test whether thrombopoietin (TPO) is entirely regulated by receptor binding or if other factors may play a role in the mechanism of TPO regulation. Therefore, we analyzed the TPO serum levels in 43 patients with reactive (secondary) thrombocytosis and in 37 with myeloproliferative thrombocytosis. Thrombocytosis was defined as a platelet level greater than 440 x 10(9)/l. Forty-two patients (98%) with reactive thrombocytosis had high concentrations of IL-6 correlating with elevated C-reactive protein levels. Twenty-three patients (53%) in this group had TPO serum concentrations of more than 300 pg/ml (normal: below 300 pg/ml). Only nine patients (24%) with myeloproliferative thrombocytosis had TPO serum levels above normal range, whereas 28 patients (76%) had normal levels of TPO. No correlation between the TPO serum levels and the concentrations of IL-6 or EPO was established. The other investigated thrombopoietic cytokines (IL-3, IL-11, GM-CSF) were unmeasurable; therefore, a correlation could not be assessed. We conclude that TPO concentrations are not strictly inversely related to platelet count. TPO serum levels are elevated especially in a considerable percentage of patients with reactive thrombocytosis, arguing for the existence of additional mechanisms of TPO regulation.

Adolescent↗
PubMed2002

Thrombocytosis is associated with a significant increase in the cancer specific death rate after radical nephrectomy.

PURPOSE: We have previously reported that patients with advanced renal cell carcinoma and a normal platelet count of 400,000/mm. have a 64% increase in life expectancy compared with those with thrombocytosis. We determined whether thrombocytosis was predictive of death from renal cell carcinoma after radical nephrectomy was performed with curative intent for early stage disease. MATERIALS AND METHODS: We reviewed the records of 204 patients with renal cell carcinoma who underwent radical nephrectomy with curative intent between June 1993 and January 2000 at Emory University Hospital. Survival, pathological grade and stage were recorded from the Emory Winship Cancer Institute tumor registry. Platelet counts were recorded and any patient with at least 1 platelet count of greater than 400,000/mm. was classified with thrombocytosis. Those with a platelet count of 400,000/mm. were classified with a normal platelet count. RESULTS: There were 26 patients with thrombocytosis and 178 patients with persistently normal platelet counts. The overall and cancer specific death rate in the 26 patients with thrombocytosis was 50% and 42%, respectively. The overall mean time between nephrectomy and death was 12.1 months in this group. The overall and cancer specific death rate in the 178 patients with a normal platelet count was 15.2% and 7.3%, respectively. Mean time to death was 22.6 months in this group. Differences in the overall and cancer specific death rates were highly statistically significant as well as clinically significant. These differences remained significant after controlling for grade, stage and histological type of cancer. CONCLUSIONS: This study documents the association of thrombocytosis with decreased survival in patients with renal cell carcinoma. In those who undergo nephrectomy for early stage renal cell carcinoma with a perioperative platelet count of greater than 400,000/mm. the cancer specific death rate from renal cell carcinoma is greater than 5 times the rate in patients with a persistently normal platelet counts after radical nephrectomy. The platelet count appears to be a new and powerful independent prognosticator in patients with renal cell carcinoma who undergo radical nephrectomy for presumed localized disease.

Aged↗
PubMed2000

Use of a platelet filter test in patients with thrombocytosis.

In the differential diagnosis of primary and secondary thrombocytosis platelet function tests may play an important role. We examined the applicability of a platelet filter test (shear-dependent platelet aggregation) as a tool, to differentiate primary thrombocytosis (cases with myeloproliferative disorders) from secondary (reactive) thrombocytosis. The test was carried out in 53 patients suffering from myeloproliferative disorders associated with primary thrombocytosis and in 21 patients with other diseases complicated by secondary thrombocytosis. Using citrate as anticoagulant, the sensitivity of the O'Brien's test proved to be 77.1%, and its specificity 94.4%. Using heparin as anticoagulant the sensitivity and specificity of the test were found to be also reliably high. Based on these studies we suggest the use of the O'Brien's filterometer as a screening test in the differential diagnosis in patients with elevated platelet count. In the case of normal results, the causes of reactive thrombocytosis should be clarified first, while with abnormal results, haematological examination of the patients should be performed.

Adenosine Diphosphate↗
PubMed1992

Thrombocytosis and thrombocytopenia in childhood bacterial meningitis.

To assess factors affecting the development of reactive thrombocytosis during bacterial meningitis, thrombocyte counts of 311 children with cerebrospinal fluid culture-positive bacterial meningitis were followed during hospitalization. Thrombocytosis (platelet counts greater than 500 x 10(9)/liter) was seen in 49% of the patients after the first week of treatment. Thrombocyte counts were higher in infants and in patients with long duration of illness before admission. Subdural effusion and cephalosporin therapy were associated with more pronounced thrombocytosis We found no relation between thrombocytosis and neurologic complications, but the patients who died developed thrombocytopenia instead of thrombocytosis. The difference between the thrombocyte curves of the surviving and dying patients might be utilized in predicting the final outcome in the severest cases of bacterial meningitis. We speculate that inflammatory cytokines, especially interleukin 1-beta, induce reactive thrombocytosis in bacterial meningitis.

Adolescent↗
PubMed1993

Drug-induced thrombocytosis.

Thrombocytosis is generally defined as platelet counts greater than 400,000/mm3. Thrombocytosis can be either primary or secondary. Adrenalin was one of the first drugs noticed to cause platelet elevations, probably due to demargination of platelets in the pulmonary vasculature. Vinca alkaloids have the most convincing data to show that they can induce thrombocytosis through their thrombocyte-stimulating properties. Miconazole has been implicated in causing thrombocytosis and has a documented case validated by drug rechallenge. Iron, predictably, can cause a transient thrombocytosis. The beta-lactam antibiotic data are very difficult to interpret due to the possibility of an acute-phase reaction in an infected patient being the cause of the thrombocytosis.

Anti-Bacterial Agents↗
PubMed2001

Neonatal thrombocytosis resulting from the maternal use of non-narcotic antischizophrenic drugs during pregnancy.

Neonatal thrombocytosis can result from maternal narcotic drug abuse. The case of a male infant is reported who was born to a woman with schizophrenia treated with non-narcotic psychotropic drugs during pregnancy; he developed severe prolonged thrombocytosis. The platelet count reached 1310 x 10(9)/l on day 15. This thrombocytosis persisted for three months. The patient was treated with dipyridamole. A bone marrow aspirate showed normal myeloid and erythroid precursors with an increased number of megakaryocytes. Plasma concentrations of interleukin 6 and thrombopoietin were suppressed. No obvious complications from the thrombocytosis occurred, and the platelet count fell to within the upper limit of normal after 3 months of age. This case indicates that thrombocytosis may occur in infants born to mothers treated with non-narcotic psychopharmaceutical drugs during pregnancy. The thrombocytosis in this case may have been induced by factors other than interleukin 6 or thrombopoietin.

Dipyridamole↗
PubMedDate not supplied

Tumor anemia and thrombocytosis in patients with vulvar cancer.

The aim of our study was to determine the prevalence of tumor anemia and thrombocytosis in patients with vulvar cancer, and to evaluate the prognostic value or pretreatment hemoglobin (Hb) and platelet count regarding disease-free and overall survival of patients with vulvar cancer. We measured pretreatment Hb and platelet count in 62 patients with squamous cell vulvar cancer. The results were correlated to clinical data. Median Hb and platelet count in patients with vulvar cancer were 13.1 g/dl (range 8.3-16.2) and 268, 500/microl (range 88,000-778,000), respectively. Cut-off levels of 12 g/dl and 300,000/microl were selected for tumor anemia and tumor thrombocytosis, respectively according to published criteria. Tumor anemia and tumor thrombocytosis were present in 30.6 and 27.4% of patients with vulvar cancer, respectively. In a univariate analysis tumor stage and tumor thrombocytosis were significantly associated with a shortened disease-free (log-rank test, p < 0.001 and p = 0. 003, respectively) and overall survival (log-rank test, p < 0.001 and p < 0.001, respectively). Tumor anemia was not associated with a shortened disease-free, but with a shortened overall survival of patients with vulvar cancer (log-rank test, p = 0.1 and p = 0.002, respectively). A multivariate Cox regression model considering tumor stage, tumor anemia, and tumor thrombocytosis showed, however, that pretreatment Hb and platelet count did not confer additional prognostic information to that already obtained by the established prognosticator tumor stage on disease free (multivariate Cox regression model, p = 0.8, p = 0.2, and p = 0.003, respectively) and overall survival (multivariate Cox regression model, p = 0.4, p = 0. 5, and p = 0.04, respectively). Pretreatment tumor anemia and tumor thrombocytosis were associated with a poor prognosis, but were not an independent predictor of outcome in patients with vulvar cancer.

Adult↗
PubMed1996

Megakaryocyte-related interleukins in reactive thrombocytosis versus autonomous thrombocythemia.

The primary thrombocytosis (thrombocythemia) associated with myeloproliferative disorders is believed to be due to autonomous platelet production. Secondary or reactive thrombocytosis can be observed in a number of clinical circumstances, and may be related to persistent overproduction of some thrombocytopoietic factors acting on megakaryocytes. Several cytokines, including IL-6, IL-1 and IL-4 have been shown to act alone or in concert, to affect various cellular stages of megakaryocytopoiesis in humans. The aim of this study is to assess the serum concentrations of these cytokines in myeloproliferative disorders (MPD) with thrombocythemia and in rheumatoid arthritis (RA) with marked reactive thrombocytosis. Twenty-two patients (14 men, 8 women) with MPD and thrombocythemia (platelet counts > 500 x 10(9)/1; range 507-996 x 10(9)/1), 33 RA patients (28 women, 5 men) with marked thrombocytosis (platelet counts > 500 x 10(9)/1; range 500-745 x 10(9)/ 1), 27 RA patients (24 women, 3 men) with normal platelet counts (range 168-399 x 10(9)/1) and 15 healthy volunteers (8 women, 7 men) with normal platelet counts (range 161-385 x 10(9)/1) enrolled in the study. Serum IL-1 alpha, IL-1 beta, IL-4 and IL-6 concentrations were measured in these four groups. Of the 22 patients with MPD, 10 had chronic myelogenous leukemia, 5 had polycythemia vera, 6 had essential thrombocytosis and 1 had osteomyelofibrosis. Serum interleukin concentrations in patients with MPD and thrombocythemia were either suppressed or similar to those of normal subjects, whereas IL-6, IL-1 beta and IL-4 levels were increased in RA patients with reactive thrombocytosis. We conclude that thrombocythemia associated with MPD is an autonomous phenomenon, and is not regulated by cytokines which affect megakaryocytopoiesis.

Adolescent↗
PubMed1999

Patients with thrombocytosis have normal or slightly elevated thrombopoietin levels.

BACKGROUND AND OBJECTIVE: The distinction between clonal and reactive thrombocytoses is a frequent problem and implies different therapeutic options. As thrombopoietin (TPO) is the main regulator of megakaryocytopoiesis and thrombopoiesis, we measured TPO levels in patients with thrombocytosis in an attempt to understand the regulation and potential utility of distinguishing thrombocytoses. DESIGN AND METHODS: Serum TPO levels, platelet counts, mean platelet volume, hemoglobin, erythrocyte sedimentation rate and age were evaluated in 25 patients with clonal thrombocytosis (15 with essential thrombocythemia, 6 with polycythemia vera and 4 with chronic myeloid leukemia) and in 50 patients with reactive thrombocytosis distributed in three groups: 1) patients in post-surgical states; 2) patients with solid tumors; and 3) patients with inflammatory diseases. RESULTS: TPO levels were slightly increased in patients with clonal (135+/-50 pg/mL) and reactive (147+/-58 pg/mL) thrombocytosis compared with controls (121+/-58 pg/mL). Analyzing the different groups, patients with essential thrombocythemia had the lowest TPO levels (120+/-28 pg/mL) and patients with solid tumors the highest levels (162+/-59 pg/mL). Patients with clonal thrombocytosis were older, had higher platelet counts, mean platelet volume and hemoglobin, and lower erythrocyte sedimentation rate than patients with reactive thrombocytosis. INTERPRETATION AND CONCLUSIONS: Minor differences were observed in TPO levels between patients with primary and secondary thrombocytoses. Erythrocyte sedimentation rate, but not TPO levels, may be a useful tool for discriminating both types of thrombocytoses.

Adolescent↗
PubMedDate not supplied

Preoperative thrombocytosis is an independent prognostic factor in stage III and IV endometrial cancer.

BACKGROUND: To identify prognostic factors in stage III and IV endometrial cancer with special attention to pretreatment platelet count. MATERIALS AND METHODS: 59 patients with FIGO stage III or IV disease operated on between 1983 and 1993 were analyzed. Patients with preoperative thrombocytosis were compared with those without thrombocytosis. Prognostic factors were analyzed with a Cox proportional hazard model. RESULTS: With the exception of age, there were no significant differences between patients with or without thrombocytosis. At multivariate analysis, five-year disease-free survival was influenced significantly by FIGO stage (stage III vs stage IV; p = 0.009), thrombocytosis (p = 0.02) and cervical involvement (p = 0.024). Similarly, overall five-year survival was significantly influenced by stage (p < 0.001), cervical involvement (p = 0.005) and thrombocytosis (p = 0.01). Age, histology, grade, myometrial invasion, lymph-vascular space involvement or spread to adnexae were not significantly associated with survival. CONCLUSION: Thrombocytosis is an independent prognostic factor in stage III and IV endometrial cancer.

Adult↗
PubMed1985

Blood coagulation and platelet profiles in persistent post-splenectomy thrombocytosis. The relationship to thromboembolism.

To clarify the possible role of persistent thrombocytosis after splenectomy being a predisposing factor causing development of thromboembolism, blood coagulation profiles and platelet functions were studied in 34 cases being 1-18 years post-splenectomy from non-malignant diseases. Persistent thrombocytosis was observed in 16 with significant negative correlation between hemoglobin level and platelet count indicated the role of anemia on persistent post-splenectomy thrombocytosis. Blood coagulation profiles showed accelerated thrombin formation or hypercoagulability as measured by thrombin generation test especially in cases with thrombocytosis, together with decreased fibrinolytic activity and high fibrinogen, but in presence of high antithrombin III activity. Concerning the platelet, the aggregation to ristocetin was defective, the improved aggregation to ADP and adrenaline was achieved only in whom with intact spleen giving defective platelet aggregation. The finding indicated the role of spleen contributing to abnormal platelet aggregation. Another interesting observation was the decreased platelet 5-hydroxytryptamine content in splenectomized cases. The overall changes on blood coagulation and platelets post-splenectomy including those with persistent thrombocytosis did not thoroughly shift to hypercoagulable state, since a high antithrombin III activity and some platelet defect remained. These present findings, therefore, unlikely predisposed to the occurrence of thromboembolism even in those with persistent thrombocytosis.

Adolescent↗
PubMed1997

Platelet distribution width for differential diagnosis of thrombocytosis.

Differential diagnosis of thrombocytosis is not always obvious. The routine clinical chemistry laboratory classically provides only limited help in distinguishing between reactive thrombocytosis (RT) and autonomous thrombocytosis, where platelet production escapes normal regulatory processes, and which is seen in myeloproliferative diseases (MPD) such as essential thrombocythemia and polycythemia vera. We explored the clinical use of platelet distribution width (PDW) in the differential diagnosis of thrombocytosis. During a 3-month period, 250 patients presenting with a platelet count > 500 x 10(9)/L were studied; 174 were classified as having RT, 42 had a diagnosis of MPD, and 34 patients were excluded because they had a hemopathy different from MPD, and either did or did not present a known etiologic factor for RT. First, we determined that in the RT group the value of PDW was closely linked to both mean platelet volume (MPV) and platelet count (PLT) (PDW = 79.5-0.005 PLT -3.5 MPV; r = 0.848, R2 = 0.720). Therefore a new parameter, PDWresidual was defined (PDWresidual = PDWobserved -PDWexpected). Second, the discrimination between reactive and autonomous thrombocytosis obtained with PDWresidual was compared with that obtained with either PDW, MPV, or PLT. PDWresidual provided much more powerful than each of the other parameters used separately: 76% of MPD patients had a PDWresidual above the 95th percentile value of the RT population and none of the MPD patients had a PDWresidual below the 50th percentile. Thus, the combined interpretation of PLT, MPV, and PDW through the use of a PDWresidual appears highly useful in the differential diagnosis of thrombocytosis. Also, through simple modeling, more information can be drawn from parameters such as PDW that hitherto were mostly discarded as being without clinical interest.

Blood Platelets↗