Mean platelet volume, thrombocytosis, and survival in non-small cell lung cancer patients treated with first-line pembrolizumab alone or with chemotherapy.

INTRODUCTION: Patients treated with immune checkpoint inhibitors (ICIs) may not response to treatment and are at risk for immune-related adverse events (irAEs). Platelet function has been linked to both oncogenesis and immune evasion. We studied the association between the change in mean platelet volume (MPV), platelet count, survival, and the risk of developing irAEs in patients with metastatic non-small cell lung cancer (NSCLC) who have received first-line ICI. METHODS: In this retrospective study, delta (∆) MPV was defined as the difference between cycle 2 and baseline MPV. Patient data were collected via chart review, and Cox proportional hazard and Kaplan-Meier method were used to assess the risk and estimate median overall survival. RESULTS: We identified 188 patients treated with first-line pembrolizumab, with or without concurrent chemotherapy. There were 80 (42.6%) patients received pembrolizumab monotherapy, and 108 (57.4%) received pembrolizumab in combination with platinum-based chemotherapy. Patients whose MPV (∆MPV ≤ 0) decreased had hazard ratio (HR) = 0.64 (95% CI 0.43-0.94) for death with p = 0.023. Patients with ∆MPV ≤ - 0.2 fL (median), there was a 58% increase in the risk of developing irAE (HR = 1.58, 95% CI 1.04-2.40, p = 0.031). Thrombocytosis at baseline and cycle 2 was associated with shorter OS with p = 0.014 and 0.039, respectively. CONCLUSION: Change in MPV after 1 cycle of pembrolizumab-based treatment was significantly associated with overall survival as well as the occurrence of irAEs in patients with metastatic NSCLC in the first-line setting. In addition, thrombocytosis was associated with poor survival.

Aberrant Platelet Aggregation as Initial Presentation of Essential Thrombocythemia: Failure of Entero-Coated Aspirin to Reduce Platelet Hyperactivation.

Essential thrombocythemia (ET) is a myeloproliferative neoplasm variant characterized by excessive production of platelets. Since the most common cause of mortality and morbidity in ET patients is thrombosis, the excessive production of platelets may cause thrombotic events. However, little is known about the function of platelets in ET. We report a female patient who presented as asymptomatic, without a remarkable medical history, and ET was diagnosed after an incidental finding of moderate thrombocytosis. Notably, together with thrombocytosis, an abnormal platelet phenotype was found for the presence of a massive, rapid and spontaneous formation of aggregates and platelet hypersensitivity to subthreshold concentrations of aggregating agonists. Bone marrow histopathological examination and genetic analysis with the JAK2 (V617F) gene mutation findings confirmed the initial suspicion of ET. Although the ET patient was placed on aspirin, the persistence of the platelet hyperactivation and hyperaggregability prompted a switch in antiplatelet medication from entero-coated (EC) to plain aspirin. As result, platelet hypersensitivity to agonists and spontaneous aggregation were no longer found. Collectively, our study demonstrates that platelet function analysis could be a reliable predictor of ET and that plain aspirin should be preferred over EC aspirin to attenuate platelet hyperreactivity.

[Role and mechanism of platelet-derived growth factor BB in thrombocytosis in Kawasaki disease]. / è¡€å°æ¿è¡ç”Ÿç”Ÿé•¿å› å­BBåœ¨å·å´Žç— è¡€å°æ¿å¢žå¤šä¸­çš„ä½œç”¨åŠæœºåˆ¶ç ”ç©¶.

OBJECTIVES: To study the role and mechanism of platelet-derived growth factor BB (PDGF-BB) on platelet production in Kawasaki disease (KD) mice and human megakaryocytic Dami cells through in vitro and invivo experiments. METHODS: ELISA was used to measure the expression of PDGF in the serum of 40 children with KD and 40 healthy children. C57BL/6 mice were used to establish a model of KD and were then randomly divided into a normal group, a KD group, and an imatinib group (30 mice in each group). Routine blood test was performed for each group, and the expression of PDGF-BB, megakaryocyte colony forming unit (CFU-MK), and the megakaryocyte marker CD41 were measured. CCK-8, flow cytometry, quantitative real-time PCR, and Western blot were used to analyze the role and mechanism of PDGF-BB in platelet production in Dami cells. RESULTS: PDGF-BB was highly expressed in the serum of KD children (P<0.001). The KD group had a higher expression level of PDGF-BB in serum (P<0.05) and significant increases in the expression of CFU-MK and CD41 (P<0.001), and the imatinib group had significant reductions in the expression of CFU-MK and CD41 (P<0.001). In vitro experiments showed that PDGF-BB promoted Dami cell proliferation, platelet production, mRNA expression of PDGFR-ß, and protein expression of p-Akt (P<0.05). Compared with the PDGF-BB group, the combination group (PDGF-BB 25 ng/mL + imatinib 20 µmol/L) had significantly lower levels of platelet production, mRNA expression of PDGFR-ß, and protein expression of p-Akt (P<0.05). CONCLUSIONS: PDGF-BB may promote megakaryocyte proliferation, differentiation, and platelet production by binding to PDGFR-ß and activating the PI3K/Akt pathway, and the PDGFR-ß inhibitor imatinib can reduce platelet production, which provides a new strategy for the treatment of thrombocytosis in KD.

Effect of iron supplementation on platelet count in adult patients with iron deficiency anemia.

Iron deficiency anemia (IDA) affects more than 1.2 billion individuals globally. In addition to anemia, reactive thrombocytosis is also a common clinical hematological condition in patients with IDA. However, some case reports have described the thrombotic complications in association with IDA-induced thrombocytosis. Patients with a high risk of thrombosis need prompt identification and effective treatment to prevent thrombotic complications. While iron replacement treatment has been shown to decrease platelet count in this context, there is limited published evidence on how iron supplementation affects the thrombocytosis caused by IDA. We retrospectively examined the clinical records of 440 patients with IDA from an RCT completed from 1 January 2016, to 30 December 2017, and data obtained from this study was used for post hoc analysis to examine the effect of iron on platelet count in IDA-induced thrombocytosis.The mean ± standard deviation (SD) platelet counts of the 440 patients with IDA was 310.23 ± 98.72 × 109/L. With baseline platelet counts>450 × 109 /L as the cutoff for thrombocytosis, patients were divided into 2 groups: 36 (8.1%) in the IDA with thrombocytosis group (mean ± SD platelet count, 521.67 ± 73.85 × 109/L) and the remaining 404 in the IDA without thrombocytosis group (mean ± SD platelet count, 291.39 ± 76.11 × 109/L).Differences were found in baseline characteristics including white blood cell (WBC) count, hemoglobin (Hb) level, mean corpuscular volume (MCV), transferrin saturation (TSAT), serum iron (SI) level, and total iron-binding capacity (TIBC) between the two groups (P < .05). From baseline to 8 weeks of continuous iron supplementation treatment, the mean platelet counts in both groups were decreased at 2-week treatment intervals. And in the IDA with thrombocytosis group, half of the patients resolved thrombocytosis after 2 weeks of iron supplementation, and the counts of all patients with thrombocytosis decreased below 450 × 109 /L within 6 weeks.In conclusion, the rate of reactive thrombocytosis in patients with IDA was 8.1%. IDA patients with thrombocytosis showed more severe anemia, lower ferritin, and more advanced iron deficiency than those without thrombocytosis. Platelet counts of half of the patients with thrombocytosis reduced below cut off of 450 × 109/L for thrombocytosis after 2 weeks of treatment, and all patients resolved thrombocytosis after 6 weeks. Our study provided clinical evidence for more effective and individualized iron management in the future. IDA patients with thrombocytosis should take active iron treatment and increase follow-up frequency to prevent thrombotic events. For patients with persistent thrombocytosis, a concomitant clonal process should be considered.

The Effect of TLR4 Blockade on Some Indicators of Systemic Inflammatory Response to Proteus mirabilis LPS in Rats.

The effects of TLR4 blocker on blood cell morphology, concentrations proinflammatory cytokines, and functional state of the liver and kidneys were studied in outbred male rats (n=60) after intravenous injection of 20 mg/kg LPS isolated from opportunistic Proteus mirabilis strain ATCC 51393. TLR4 blocker TLR4-IN-C34 was injected intravenously in a dose of 1 mg/kg/day over 3 days. Systemic inflammatory reaction induced by LPS was characterized by elevation of serum TNFα, IL-1ß, IL-6, erythrocyte sedimentation rate, leukocytosis, and thrombocytosis. Increased activity of hepatocyte enzymes (ALT, alkaline phosphatase, and lactate dehydrogenase), retention of nitrogen metabolites (urea and creatinine), elevated content of protein oxidation products, and enhanced protein catabolism were also observed. Administration of TLR4 blocker reduced parameters of inflammatory reaction and prevented the development of hypercatabolic syndrome; endotoxicosis and kidney function indicators approached the normal levels.

Aggregometry in the settings of thrombocytopenia, thrombocytosis and antiplatelet therapy.

A variety of laboratory tests have been developed, which can diagnose a number of both congenital and acquired disorders of platelet function. Many tests of platelet function measure the ability of platelets to adhere to each other, forming platelet aggregates, which represent the major constituents of hemostatic plugs and of arterial thrombi. Light transmission aggregometry (LTA) is still considered the gold standard of platelet aggregation tests, but other platelet aggregation-based tests are also available. Among them, the flow cytometry-based methods may be more convenient than LTA for the study of patients with very low or very high platelet counts. The use of platelet aggregation tests has also been advocated to monitor the treatment with antiplatelet agents (mostly the P2Y12 antagonist clopidogrel) of patients with thrombotic arterial occlusions, with the aim of improving their efficacy and safety. However, randomized clinical trials failed to show any advantage of this strategy; as a consequence, international guidelines now recommend against laboratory monitoring of antiplatelet therapy.

Cyclic thrombocytopenia synchronizing with the menstrual cycle showing periodic phases of thrombocytopenia and rebound thrombocytosis.

A 37-year-old woman was admitted to our hospital for purpura involving the extremities and thrombocytopenia. Prednisolone (PSL) was administered based on a diagnosis of idiopathic thrombocytopenic purpura (ITP), but was not effective for maintaining her platelet count within the normal range, which showed cyclic fluctuation corresponding to the menstrual cycle. Therefore, we discontinued PSL, and cyclic thrombocytopenia (CTP) was diagnosed. CTP is a rare disease which is usually treated as ITP but with no response. Although the exact cause of CTP is uncertain, in our case, a hormonal mechanism may be responsible for fluctuating platelet count.

Paraneoplastic thrombocytosis: the secrets of tumor self-promotion.

Paraneoplastic thrombocytosis is associated with many solid tumors and often correlates with reduced survival. Recent studies suggest that a pathogenic feed back loop may be operative between platelets and tumor cells, with reciprocal interactions between tumor growth/metastasis and thrombocytosis/platelet activation. Specific molecular pathways have been identified in which tumors can stimulate platelet production and activation; activated platelets can, in turn, promote tumor growth and metastasis. Taken together, these findings provide exciting new potential targets for therapeutic intervention.

Germ-line JAK2 mutations in the kinase domain are responsible for hereditary thrombocytosis and are resistant to JAK2 and HSP90 inhibitors.

The main molecular basis of essential thrombocythemia and hereditary thrombocytosis is acquired, and germ-line-activating mutations affect the thrombopoietin signaling axis. We have identified 2 families with hereditary thrombocytosis presenting novel heterozygous germ-line mutations of JAK2. One family carries the JAK2 R867Q mutation located in the kinase domain, whereas the other presents 2 JAK2 mutations, S755R/R938Q, located in cis in both the pseudokinase and kinase domains. Expression of Janus kinase 2 (JAK2) R867Q and S755R/R938Q induced spontaneous growth of Ba/F3-thrombopoietin receptor (MPL) but not of Ba/F3-human receptor of erythropoietin cells. Interestingly, both Ba/F3-MPL cells expressing the mutants and platelets from patients displayed thrombopoietin-independent phosphorylation of signal transducer and activator of transcription 1. The JAK2 R867Q and S755R/R938Q proteins had significantly longer half-lives compared with JAK2 V617F. The longer half-lives correlated with increased binding to the heat shock protein 90 (HSP90) chaperone and with higher MPL cell-surface expression. Moreover, these mutants were less sensitive to JAK2 and HSP90 inhibitors than JAK2 V617F. Our results suggest that the mutations in the kinase domain of JAK2 may confer a weak activation of signaling specifically dependent on MPL while inducing a decreased sensitivity to clinically available JAK2 inhibitors.

JAK2 inhibitors do not affect stem cells present in the spleens of patients with myelofibrosis.

Dysregulation of Janus kinase (JAK)-signal transducer and activator of transcription signaling is central to the pathogenesis of myelofibrosis (MF). JAK2 inhibitor therapy in MF patients results in a rapid reduction of the degree of splenomegaly, yet the mechanism underlying this effect remains unknown. The in vitro treatment of splenic and peripheral blood MF CD34(+) cells with the JAK1/2/3 inhibitor, AZD1480, reduced the absolute number of CD34(+), CD34(+)CD90(+), and CD34(+)CXCR4(+) cells as well as assayable hematopoietic progenitor cells (HPCs) irrespective of the JAK2 and calreticulin mutational status. Furthermore, AZD1480 treatment resulted in only a modest reduction in the proportion of HPCs that were JAK2V617F(+) or had a chromosomal abnormality. To study the effect of the drug on MF stem cells (MF-SCs), splenic CD34(+) cells were treated with AZD1480 and transplanted into immunodeficient mice. JAK2 inhibitor therapy did not affect the degree of human cell chimerism or the proportion of malignant donor cells. These data indicate that JAK2 inhibitor treatment affects a subpopulation of MF-HPCs, while sparing another HPC subpopulation as well as MF-SCs. This pattern of activity might account for the reduction in spleen size observed with JAK2 inhibitor therapy as well as the rapid increase in spleen size observed frequently with its discontinuation.

Thrombosis in thrombocythemic Ph- myeloproliferations is associated with higher platelet count prior to the event: results of analyses of prothrombotic risk factors from a registry of patients treated with anagrelide.

Controversies still exist regarding definition of the thrombotic risks in Ph- (BCR/ABL1-) myeloproliferative disorders with thrombocythemia (MPD-T). Platelet counts at diagnosis are currently not taken as a risk factor of thrombosis. In our cohort of 1179 patients with MPD-T, prospectively registered for anagrelide treatment, we found that the median platelet count prior to the thrombotic event was significantly higher than at time points without any ensuing thrombosis (453 vs. 400 × 10(9)/L, P < 0.001), albeit higher platelet counts at diagnosis tended to be connected with fewer thrombotic events (in contrast to WBC counts at diagnosis). The JAK2(V617F) mutation predicted both arterial and venous events, while age >65 yr, hypertension, diabetes mellitus, smoking, elevated triglyceride and homocysteine levels predicted arterial events only. For venous events, the specific thrombophilic risk factors (factor V 'Leiden' and others), antiphospholipid antibodies, and elevated factor VIII levels played a major role. During anagrelide treatment (± aspirin), we documented a decrease in both venous (6.7-fold) and arterial events (1.8-fold), while bleeding (mostly minor events) increased twofold compared to history. Our results suggest that keeping platelet counts at low levels may be a meaningful therapeutic measure to prevent thrombosis, although their counts at diagnosis lack any prognostic value.

Refractory anemia with ring sideroblasts and RARS with thrombocytosis.

DISEASE OVERVIEW: Ring sideroblasts (RS) are erythroid precursors with abnormal perinuclear mitochondrial iron accumulation. Two myeloid neoplasms defined by the presence of RS, include refractory anemia with ring sideroblasts (RARS) and RARS with thrombocytosis (RARS-T). DIAGNOSIS: RARS is a lower risk myelodysplastic syndrome (MDS) with dysplasia limited to the erythroid lineage, <5% bone marrow (BM) blasts and ≥15% BM RS. RARS-T is a provisional entity in the MDS/MPN (myeloproliferative neoplasm) overlap syndromes, with diagnostic features of RARS, along with a platelet count ≥450 × 10(9)/L and large atypical megakaryocytes similar to those observed in BCR-ABL1 negative MPN. Mutations and Karyotype: Mutations in the SF3B1 gene are seen in ≥80% of patients with RARS and RARS-T, and strongly correlate with the presence of BM RS; RARS-T patients have additional mutations such as, JAK2V617F (∼60%), MPL (<5%), and CALR (<5%). Cytogenetic abnormalities are uncommon in both RARS and RARS-T. RISK STRATIFICATION: Most patients with RARS are stratified into lower risk groups by the International Prognostic Scoring System (IPSS) for MDS and the revised IPSS. Disease outcome in RARS-T is better than that of RARS, but worse than that of essential thrombocytosis. Both RARS and RARS-T have a low risk of leukemic transformation. TREATMENT: Anemia and iron overload are complications in both diseases and are managed similar to lower risk MDS. Aspirin therapy is reasonable in RARS-T, especially in the presence of JAK2V617F, but the value of platelet-lowering drugs is uncertain. Case reports of RARS-T therapy with lenalidomide warrant additional studies.

Rebound Thrombocytosis following Induction Chemotherapy is an Independent Predictor of a Good Prognosis in Acute Myeloid Leukemia Patients Attaining First Complete Remission.

There are very few data about the relationship between acute myeloid leukemia (AML) prognosis and bone marrow recovery kinetics following chemotherapy. In this study, we aimed to assess the prognostic importance and clinical associations of neutrophil and platelet recovery rates and rebound thrombocytosis (RT) or neutrophilia (RN) in the postchemotherapy period for newly diagnosed AML patients. De novo AML patients diagnosed between October 2002 and December 2013 were evaluated retrospectively. One hundred patients were suitable for inclusion. Cox regression analysis using need for reinduction chemotherapy as a stratification parameter revealed RT as the only parameter predictive of OS, with borderline statistical significance (p = 0.06, OR = 7; 95% CI 0.92-53), and it was the only parameter predictive of DFS (p = 0.024, OR = 10; 95% CI 1.3-75). In order to understand whether RT or RN was related to a better marrow capacity or late consolidation, we considered neutrophil recovery time and platelet recovery time and nadir-first consolidation durations in all patients in the cohort. Both the marrow recovery duration and the time between marrow aplasia and first consolidation were shorter in RT and RN patients. To our knowledge, this is the first study to report a correlation between RT/RN and prognosis in AML.

Thrombocytosis is associated with increased short and long term mortality after exacerbation of chronic obstructive pulmonary disease: a role for antiplatelet therapy?

INTRODUCTION: Evidence suggests that platelets play a significant role in inflammation in addition to their role in thrombosis. Systemic inflammation is linked to poor short and long term outcomes in COPD. Increased platelet activation has been reported in acute exacerbations of COPD (AECOPD). We investigated whether thrombocytosis is independently associated with poor outcomes following AECOPD. METHODS: An observational cohort study of patients hospitalised with AECOPD was performed. Patients were >40 years with spirometry confirmed COPD admitted between 2009 and 2011. Platelet count was recorded on admission. The primary outcome was 1-year all-cause mortality. Secondary outcomes included inhospital mortality and cardiovascular events. Analyses were conducted using logistic regression after adjustment for confounding variables. RESULTS: 1343 patients (49% male) were included. Median age was 72 years (IQR 63-79 years). 157 (11.7%) had thrombocytosis. Thrombocytosis was associated with both 1-year mortality and inhospital mortality; OR 1.53 (95% CI 1.03 to 2.29, p=0.030) and OR 2.37 (95% CI 1.29 to 4.34, p=0.005), respectively. Cardiovascular hospitalisation was not significantly increased (OR 1.13 (95% CI 0.73 to 1.76, p=0.600)) in patients with thrombocytosis. Aspirin or clopidogrel treatment correlated with a reduction in 1-year mortality (OR 0.63 (95% CI 0.47 to 0.85, p=0.003)) but not inhospital mortality (OR 0.69 (95% CI 0.41 to 1.11, p=0.124)). CONCLUSIONS: After adjustment for confounders thrombocytosis was associated with increased 1-year mortality after exacerbation of COPD. Antiplatelet therapy was associated with significantly lower 1-year mortality and may have a protective role to play in patients with AECOPD.

Thrombocythemia and polycythemia in patients younger than 20 years at diagnosis: clinical and biologic features, treatment, and long-term outcome.

Sixty-four patients < 20 years of age, investigated for a suspicion of Philadelphia-negative myeloproliferative disease (MPD), were retrospectively evaluated to characterize the different forms and to examine the treatments used and long-term outcome. JAK2 mutations, endogenous erythroid colony growth, and clonality were investigated in 51 children. Mutations of thrombopoietin, the thrombopoietin receptor (MPL), and the erythropoietin receptor and mutations of other genes involved in the pathogenesis of MPD were investigated in JAK2 wild-type patients. Based on our criteria for childhood MPD, we identified 34 patients with sporadic thrombocythemia (ST), 16 with hereditary thrombocytosis (HT), 11 with sporadic polycythemia (SP), and 3 with hereditary polycythemia (HP). JAK2(V617F) mutations were present in 47.5% of ST and in no HT. The MPL(S505A) mutation was detected in 15/16 HT patients and in no ST (P < .00001). The JAK2(V617F) mutation occurred in 27% of SP patients diagnosed according to the Polycythemia Vera Study Group or World Health Organization 2001 criteria. Children with ST received more cytoreductive drugs than those with HT (P = .0006). After a median follow-up of 124 months, no patient had developed leukemia or myelofibrosis and 5% had thrombosis; the miscarriage rate in thrombocythemic patients was 14%. The low complication rate in our population suggests that children with MPD may be managed by tailored approaches.

Artemisia vulgaris L. ethanolic leaf extract reverses thrombocytopenia/thrombocytosis and averts end-stage disease of experimental severe Plasmodium berghei murine malaria.

BACKGROUND & OBJECTIVES: Artemisinin isolated from Artemisia annua is the most potent antimalarial against chloroquine resistant Plasmodium falciparum malaria. We previously reported that the ethanolic leaf extract of Artemisia vulgaris, an invasive weed and the only Artemisia species in Sri Lanka, possess both potent and safe antimalarial activity (in terms of antiparasitic properties) in a P. berghei murine malaria model. We report here a prototype study that investigated antidisease activities of A. vulgaris ethanolic leaf extract (AVELE) in a P. berghei ANKA murine malaria model that elicit pathogenesis similar to falciparum malaria. Profound thrombocytosis and thrombocytopenia in mice were detected in early-stage (Day 3), and at a later stage of infection (Day 6), respectively. Plasmodium berghei infected mice, 7 or 8 days post-infection reached end-stage disease with rapid drop in body temperature and usually die within 24 h, as a consequence of cerebral malaria. METHODS: Three doses of the AVELE (500, 750 and 1000 mg/kg) were used to assess antidisease activity of A. vulgaris in terms of survival, effects on thrombocyte related pathology and end-stage disease, antipyretic activity, and antinociception, using standard methodology. RESULTS: The 1000 mg/kg dose of AVELE significantly increased survival, reversed the profound thrombocytopenia/ thrombocytosis (p ≤0.01), altered the end-stage disease (p ≤0.05), and manifested significant antipyretic and antinociceptive (p ≤0.05) activities. INTERPRETATION & CONCLUSION: We conclude that a crude ethanolic leaf extract of A. vulgaris, showed potent antimalarial properties, in terms of antidisease activities; antipyretic activity, peripheral and central antinociception, increased survival, averted end-stage disease and reversed thrombocytopenia/thrombocytosis.