Evaluation of Absolute Neutrophil, Lymphocyte and Platelet Count and Their Ratios as Predictors of Thrombotic Risk in Patients with Prefibrotic and Overt Myelofibrosis

AIM

To investigate the prognostic contribution of absolute neutrophil (ANC), lymphocyte (ALC), platelet count and their ratios, neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR), to thrombotic risk in patients with prefibrotic and overt fibrotic myelofibrosis (MF).

METHODS

We retrospectively analyzed a cohort of 256 patients with prefibrotic (85 patients) and overt fibrotic MF (171 patients) treated in six Croatian hematological centers.

RESULTS

Prefibrotic compared to overt fibrotic MF patients presented with significantly higher ALC, platelet count and PLR, and experienced longer time to thrombosis (TTT). Among prefibrotic patients, ANC > 8.33 × 109/L (HR 13.08, p = 0.036), ALC > 2.58 × 109/L (HR 20.63, p = 0.049) and platelet count > 752 × 109/L (HR 10.5, p = 0.043) remained independently associated with shorter TTT. Among overt fibrotic patients, ANC > 8.8 × 109/L (HR 4.49, p = 0.004), ALC ≤ 1.43 × 109/L (HR 4.15, p = 0.003), platelet count ≤ 385 × 109/L (HR 4.68, p = 0.004) and chronic kidney disease (HR 9.07, p < 0.001) remained independently associated with shorter TTT.

CONCLUSIONS

Prognostic properties of ANC, ALC and platelet count are mutually independent and exceed those of NLR and PLR regarding thrombotic risk stratification. ALC and platelet count associate in opposite directions with thrombotic risk in prefibrotic and overt fibrotic MF patients.

Treatment-Related Risk Factors for Adverse Outcomes of COVID-19 in Patients Treated for Lymphoid Malignancies in the Pre-Omicron Era-A Study of KroHem, the Croatian Group for Hematologic Diseases

Patients with lymphoid malignancies are at increased risk of death or prolonged infection due to COVID-19. Data on the influence of different antineoplastic treatment modalities on outcomes are conflicting. Anti-CD20 monoclonal antibodies increase the risk of prolonged infection. It is unclear whether this risk is affected by the choice of the antibody (rituximab vs. obinutuzumab). To elucidate the role of antineoplastic therapy on COVID-19 outcomes, KroHem collected data on patients with lymphoid malignancies diagnosed with COVID-19 between October 2020 and April 2021. A total of 314 patients were identified, 75 untreated, 61 off treatment and 178 on treatment. The mortality rate in untreated and off-treatment patients was 15% and 16%; 9% and 10% had prolonged infection. In the on-treatment group, 3% were still prolonged positive at time of data collection, 62% recovered and 35% died; 42% had prolonged infection. Disease type, use of anti-CD20 monoclonal antibodies, prior autologous stem-cell transplantation (ASCT) and line of treatment did not significantly affect mortality. Mortality was higher in older patients (p = 0.0078) and those treated with purine analogues (p = 0.012). Prolonged COVID-19 was significantly more frequent in patients treated with anti-CD20 monoclonal antibodies (p = 0.012), especially obinutuzumab, and purine analogues (p = 0.012). Age, prior ASCT and treatment line did not significantly affect risk of prolonged infection. These data suggest that increased age and use of purine analogues are main risk factors for increased mortality of COVID-19 in patients with lymphoid malignancies. Obinutuzumab further increases the risk of prolonged disease, but not of death, in comparison to rituximab. Epidemiological considerations should be taken into account when choosing the appropriate antineoplastic therapy for patients with lymphoid malignancies.

Prolonged Proton Pump Inhibitor Use and Thrombohemorrhagic Risk in Essential Thrombocythemia and Polycythemia Vera Patients Treated with Long-Term Aspirin: A Pilot Study

INTRODUCTION

Proton pump inhibitors (PPIs) are known to decrease the risk of gastrointestinal (GI) bleeding. However, concerns have been raised regarding the potential pharmacodynamic interactions of PPIs and antiplatelet drugs with respect to cardiovascular risk. Patients with BCR::ABL1-negative myeloproliferative neoplasms (MPNs), essential thrombocythemia (ET), and polycythemia vera (PV) often suffer from peptic ulcer disease (PUD) and frequently receive low-dose aspirin due to an intrinsically high thrombotic risk.

METHOD

This retrospective multicenter study from a community setting investigated whether continuous PPI use may affect thrombohemorrhagic risk in ET and PV patients treated with long-term aspirin.

RESULTS

Ninety-four aspirin-treated MPN patients (ET = 36, PV = 58) were included; median age was 69.5 years (range 21-92) and 40 (42.6%) were males. Nineteen (20.2%) patients continuously received PPIs and pantoprazole (n = 15, 78.9%) was the most frequently received PPI. PV phenotype (p = 0.085), male sex (p = 0.011), and prior thrombosis (p = 0.005) were associated with PPI use, whereas no correlations were found with respect to age, disease risk, splenomegaly, mutational status, constitutional symptoms, cardiovascular risk factors, cytoreductive treatment, or any of the blood cell counts (p > 0.050 for all analyses). The median follow-up time was 55.5 months; 19 (20.2%) thrombotic and 13 (13.8%) bleeding events occurred during this time. The use of PPIs was not associated with an increased risk of thrombosis (p = 0.158) or overall bleeding (p = 0.229) and none of the patients treated with PPIs experienced GI bleeding.

CONCLUSIONS

Considering that Helicobacter pylori infection and PUD are quite frequent in ET and PV patients, these preliminary results may provide some reassurance to physicians regarding the absence of thrombohemorrhagic risk associated with prolonged PPI use in MPN patients treated with long-term aspirin. Our observations may be even more important in the light of recent evidence suggesting suboptimal platelet inhibition in ET with once-daily when compared to twice- or triple-daily aspirin which may also cause more abdominal discomfort. Limitations of this study are its retrospective design, limited number of patients included, and the lack of pharmacodynamic and pharmacokinetic assessments.

Higher estimated plasma volume status is associated with increased thrombotic risk and impaired survival in patients with primary myelofibrosis

Introduction

Blood plasma represents a large reservoir of cytokines and other mediators of inflammation. Higher estimated plasma volume status (ePVS) has been shown to correlate with increased thrombotic risk in polycythemia vera patients, but its clinical and prognostic associations in patients with myelofibrosis are unknown which we aim to evaluate in this study.

Materials and methods

We retrospectively analysed a multicentric cohort of 238 patients with primary (PMF) and secondary myelofibrosis (SMF). Estimated plasma volume status was calculated using the Strauss-derived Duarte formula. Overall survival (OS) and time to thrombosis (TTT) considering both arterial and venous thromboses were primary endpoints of interest.

Results

Median ePVS was 5.8 dL/g and it did not significantly differ between PMF and SMF patients. Patients with more advanced disease features, more pronounced inflammation and higher comorbidity burden had higher ePVS. Higher ePVS (> 5.6 dL/g) was associated with shorter OS in PMF (unadjusted hazard ratio, HR = 2.8, 95% confidence interval, CI (1.79-4.41), P < 0.001) and SMF (unadjusted HR = 2.55, 95% CI (1.1-5.71), P =0.025) and with shorter TTT in PMF (> 7 dL/g, unadjusted HR = 4.1, 95% CI (1.44-11.59), P = 0.009) patients. Associations with OS diminished in multivariate analyses after adjustments for the dynamic-international-prognostic-scoring-system (DIPSS) and myelofibrosis-secondary-to-PV-and ET-prognostic-model (MYSEC-PM), respectively. Association with TTT remained significant independently of JAK2 mutation, white blood cell count and chronic kidney disease.

Conclusions

Myelofibrosis patients with more advanced disease features and more pronounced inflammation have higher ePVS, indicative of expanded plasma volume. Higher ePVS is associated with impaired survival in PMF and SMF and higher thrombotic risk in PMF patients.

Hip and Knee Osteoarthritis in Patients with Chronic Myeloproliferative Neoplasms: A Cross-Sectional Study

BACKGROUND

Osteoarthritis (OA) is a progressive degenerative disease with an inflammatory background. Chronic myeloproliferative neoplasms (MPN) are clonal hematopoietic disorders characterized by chronic inflammation and a tendency for connective tissue remodeling.

AIM

This study aimed to investigate the prevalence and associated risk factors of symptomatic OA (sOA) in MPN patients.

PATIENTS AND METHODS

A total of 100 consecutive MPN (39 essential-thrombocythemia, 34 polycythemia-vera, 27 myelofibrosis) patients treated in two community hematologic centers were cross-sectionally evaluated. Patients were required to have both symptoms attributable to hip and/or knee OA and radiographic confirmation to be considered as having sOA.

RESULTS

The prevalence of hip and/or knee sOA was significantly higher among MPN patients than the previously reported prevalence in the general population of similar age (61% vs. 22%, p < 0.001). Hip sOA was present in 50%, knee sOA in 51% and sOA of both localizations in 41% of patients. A high proportion of MPN patients had radiographic signs of hip OA (94%) and knee OA (98%) in the presence of attributable symptoms. Among the other factors, sOA was univariately associated with the presence of JAK2 mutation, myelofibrosis phenotype, older age, higher body weight, and higher MPN-SAF score (p < 0.050 for all analyses). In the multivariate analysis, older age (odds ratio = 1.19, 95% confidence interval-CI 1.06-1.33) and higher body weight (OR = 1.15, 95% CI 1.06-1.25) were recognized as independent risk factors for sOA. On the other hand, cytoreductive treatment was a protective factor for sOA (OR = 0.07, 95% CI 0.006-0.86).

CONCLUSIONS

The prevalence of sOA in MPN patients was higher than that in the general population and seems to correlate with older age, increased myeloproliferation and a higher inflammatory state. Whether cytoreductive treatment may postpone OA development in MPN patients warrants additional confirmation.

Dose-adjusted EPOCH and rituximab (DA-EPOCH-R) in older patients with high-risk aggressive diffuse large B-cell lymphoma: a real-life multicenter study by the Croatian Cooperative Group for Hematologic diseases (KroHem)

PURPOSE

DA-EPOCH-R is a regimen used for treatment of high-risk diffuse large B-cell lymphoma (DLBCL), designed to overcome resistance to standard R-CHOP by combining prolonged exposure of lymphoma cells to cytotoxic agents and dose-adjustment based on toxicity. Data on outcomes of older patients are scarce.

PATIENTS AND METHODS

We collected data on patients with newly diagnosed high-risk DLBCL older than 60 years treated with DA-EPOCH-R. High-risk patients were defined by the age-adjusted international prognostic index score 2 or 3.

RESULTS

A total of 120 patients were included. Median age was 69 years (range 60-82). Response rate was 74%; with 59% complete responses. Dose of DA-EPOCH-R was escalated in 50 patients (42%). Three-year progression-free survival (PFS) and overall survival (OS) was 53% and 58%, respectively, with treatment-related mortality (TRM) of 13%. In univariate analysis favorable prognostic factors were performance status (PS) (0-2 vs. 3-4), age (<70 vs. ≥70 years), and center. In multivariate analysis, PS and center retained prognostic significance. Patients with PS 0-2 had a 3-year PFS and OS 58% and 64%, respectively, with TRM of 6%.

CONCLUSION

DA-EPOCH-R is efficacious in sufficiently fit older high-risk DLBCL patients. Patients with poor PS have unacceptable toxicity and require less intensive therapy.

MPN-541 Estimated Plasma Volume Status in Patients With Primary Myelofibrosis and Associated Thrombotic and Mortality Risks

CONTEXT

Blood plasma experiences substantial changes in both volume and composition in patients with chronic myeloproliferative neoplasms (MPN) and represents a large reservoir of cytokines and other mediators of inflammation. Higher estimated plasma volume status (ePVS) has recently been shown to correlate with increased thrombotic risk in polycythemia vera patients.

OBJECTIVE

To estimate clinical and prognostic associations of ePVS in patients with myelofibrosis.

DESIGN

Retrospective cohort study.

SETTING

6 hematology centers.

PATIENTS

238 myelofibrosis patients, 168 with PMF, 34 with post-PV SMF and 36 with post-ET SMF.

INTERVENTIONS

ePVS was calculated using the Strauss derived Duarte formula: (100-hematocrit (%)/hemoglobin (g/dL) and expressed as dl/g.

MAIN OUTCOME MEASURES

Overall survival (OS) and time to thrombosis (TTT).

RESULTS

Median ePVS was 5.8 dl/g and it did not significantly differ between PMF and SMF patients. Among other associations, higher ePVS was significantly associated with higher degree of bone-marrow fibrosis, absence of JAK2-mutation, lower white blood cells (WBC), platelets and hemoglobin, presence of circulatory blasts, higher C-reactive protein, higher lactate dehydrogenase, lower albumin and higher Charlson comorbidity index in an overall cohort, as well as with more pronounced splenomegaly and higher Dynamic International Prognostic Scoring System (DIPSS) risk in primary myelofibrosis (PMF) and higher Mysec-PM risk in secondary myelofibrosis (SMF) patients (P<0.05 for all analyses). Higher ePVS (>5.6 dl/g) was associated with shorter overall-survival (OS) in PMF (HR=2.8, P<0.001) and SMF (HR=2.55, P=0.025) and with shorter time-to-thrombosis in PMF (>7 dl/g, HR=4.1, P=0.009) patients. Associations with overall survival diminished in multivariate analyses after adjustments for DIPSS and Mysec-PM, respectively. Association with TTT remained significant independently of JAK2, WBC and chronic kidney disease.

CONCLUSIONS

Myelofibrosis patients with more advanced disease features and more pronounced inflammation have higher ePVS, indicative of expanded plasma volume. Higher ePVS is associated with impaired survival in PMF and SMF and higher thrombotic risk in PMF patients.

High platelet-to-lymphocyte ratio may differentiate polycythemia vera from secondary polycythemia

Discriminating polycythemia vera (PV) from secondary polycythemia (SP) is crucial due to the inherent risk of thrombosis in PV and different treatment approaches. The majority of PV patients have subnormal serum erythropoietin levels and harbor Janus kinase 2 (JAK2) mutations; however, serum erythropoietin levels may be normal in approximately one third of PV patients and mutational analysis is costly and requires access to specialized laboratories. Recently, neutrophil-to-lymphocyte (NLR) and platelet-to-lymphocyte ratios (PLR) emerged as rapidly available biomarkers to identify PV patients under an increased risk of thrombosis and death. This multicenter retrospective study investigated whether these two biomarkers may also be used to differentiate PV from SP. A total of 207 subjects were included (103 PV and 104 SP) with both baseline NLR (median 4.33 vs. 1.89) and PLR (median 259.12 vs. 81.11) being significantly higher in PV than in SP (p < 0.001 for both analyses). According to the receiver operating curve analysis, PLR (area under the curve, AUC 0.936, the optimal cut-off value of > 138.1 had 82.5% sensitivity and 91.67% specificity for the detection of PV) outperformed other tested variables (NLR, total leukocytes, neutrophils, lymphocytes and platelets) and its cut-off values with 100% specificity and sensitivity were able to confirm (PLR > 224.56; 31% patients) and to exclude (PLR < 68.8; 13% patients) the highest proportions of PV patients. Therefore, PLR may represent a cheap and a rapidly available biomarker with valuable diagnostic and prognostic properties. This information may be particularly useful in resource-limited settings; however, our results need validation on larger datasets.

Beneficial effect of ACE inhibitors on kidney function in polycythemia vera

BACKGROUND

Reduced kidney function has been associated with worse clinical outcomes in patients with myeloproliferative neoplasms (MPN). Statins and angiotensin-converting enzyme inhibitors (ACE-i) have renoprotective properties and their pleiotropic effects might also affect the malignant MPN clone; however, whether concomitant use of statins and ACE‑i has a positive effect on estimated glomerular filtration rate (eGFR) in polycythemia vera (PV) patients is currently unknown.

METHODS

This multicenter retrospective study investigated effects of statins and ACE‑i on 12-month eGFR dynamics in 75 PV patients.

RESULTS

Of the patients 25 (33.3%) had a 10% or more increase in eGFR at 12 months. Univariately, statins (55.5% vs. 16.3%; p = 0.022), ACE‑i (61% vs. 24.6%; p = 0.004), male sex (54.3%, vs. 15%; p < 0.001) and the absence of chronic kidney disease (CKD, 45.5% vs. 16.1%; p = 0.008) were statistically significantly associated with an improvement in eGFR. ACE‑i (p = 0.008), CKD (p < 0.001), male sex (p = 0.004) and higher baseline eGFR (p = 0.007) remained statistically significantly associated with an improvement in eGFR in the multivariate logistic regression model also including statins, hydroxyurea, high-risk disease, cardiovascular risk factors, chronic heart failure and baseline hematocrit.

CONCLUSION

The ACE‑i might have renoprotective properties in PV. Further studies are needed to elucidate whether the use of these drugs could also affect other MPN-related outcomes.

Circulating YKL-40 in Philadelphia-negative myeloproliferative neoplasms

Objectives: Philadelphia-negative chronic myeloproliferative neoplasms (MPNs), essential thrombocythemia (ET), polycythemia vera (PV) and myelofibrosis (MF), are characterized by clonal myeloproliferation and a strong inflammatory atmosphere. YKL-40, expressed in granulocytes, macrophages, megakaryocytes and malignant cells, is an acute phase reactant with an important role in tissue remodeling and atherosclerotic inflammation. The aim of this study was to investigate serum YKL-40 levels in MPNs and to assess its clinical correlations. Methods: ELISA test was used to measure serum YKL-40 levels in 111 MPN patients and in 32 healthy controls. Results: Serum YKL-40 levels were higher in ET, post-ET MF, PV, post-PV MF and primary MF patients, when compared to healthy controls (p < 0.001). Higher serum YKL-40 levels were associated with parameters indicative of the increased inflammatory state (higher C-reactive protein, poor performance status, presence of constitutional symptoms and cardiovascular risk factors). Additionally, higher serum YKL-40 levels in MF patients were associated with blast phase disease, lower hemoglobin and higher Dynamic International Prognostic Scoring System score. In the multivariate Cox regression models, higher serum YKL-40 levels in ET and PV patients were independently associated with an increased risk of thrombosis (HR 4.64, p = 0.031) and impaired survival in MF patients (HR 4.31, p = 0.038). Conclusion: These results indicate that higher circulating YKL-40 levels in MPNs might have a pathophysiological role in disease progression and thrombosis development. Assessing circulating YKL-40 could help in identification of ET and PV patients at a high risk of future cardiovascular events and has a good potential for improving prognostication of MF patients.

Higher serum uric acid is associated with higher risks of thrombosis and death in patients with primary myelofibrosis

BACKGROUND

Serum uric acid (SUA) can promote inflammation and is associated with increased cardiovascular morbidity. Primary (PMF) and secondary myelofibrosis (SMF) are myeloproliferative neoplasms characterized by high cellular turnover and substantial risk of thrombosis and death.

METHODS

We have retrospectively investigated SUA in 173 patients with myelofibrosis (125 PMF; 48 SMF) and 30 controls.

RESULTS

The PMF patients had significantly higher SUA in comparison to SMF and controls. In both PMF and SMF higher SUA was significantly associated with arterial hypertension and decreased renal function. Among PMF patients, higher SUA was significantly associated with older age, larger spleen, higher white blood cell counts, higher lactate dehydrogenase, lower immunoglobulin G levels, allopurinol use and non-smoking. Among SMF patients, higher SUA was associated with male sex (P < 0.05 for all analyses). In PMF higher SUA was univariately associated with inferior survival (> 427 μmol/L hazard ratio (HR) = 2.22; P = 0.006) and shorter time to thrombosis (> 444 μmol/L HR = 5.05; P = 0.006), which could be shown separately for arterial (> 380 μmol/L; HR = 4.9; P = 0.013) and venous thromboses (> 530 μmol/L; HR = 17.9; P < 0.001). In multivariate analyses, SUA remained significantly associated with inferior survival independent of the Dynamic International Prognostic Staging System and with shorter time to thrombosis independent of age in PMF patients; however, the prognostic significance of SUA was diminished after including serum creatinine in the models. SUA was not prognostic in SMF patients.

CONCLUSION

The PMF patients present with higher SUA levels, which are associated with features of more advanced disease and higher risks of arterial and venous thrombosis and death.

Reduced renal function strongly affects survival and thrombosis in patients with myelofibrosis

We retrospectively investigated a cohort of 176 myelofibrosis patients (128 primary-PMF; 48 secondary-SMF) from five hematology centers. The presence of chronic kidney disease (CKD) was determined in addition to other clinical characteristics. CKD was present in 26.1% of MF patients and was significantly associated with older age (P < 0.001), higher WBC (P = 0.015), and its subsets (neutrophil, monocyte, and basophil counts), higher platelets (P = 0.001), lower albumin (P = 0.018), higher serum uric acid (P = 0.001), higher LDH (P = 0.022), and the presence of CV risk factors (P = 0.011). There was no significant association with driver mutations, degree of bone marrow fibrosis, PMF/SMF, or DIPSS risk categories (P > 0.05 for all analyses). The presence of CKD was significantly associated with shorter time to arterial (HR = 3.49; P = 0.041) and venous thrombosis (HR = 7.08; P = 0.030) as well as with shorter overall survival (HR 2.08; P = 0.009). In multivariate analyses, CKD (HR = 1.8; P = 0.014) was associated with shorter survival independently of the DIPSS (HR = 2.7; P < 0.001); its effect being more pronounced in lower (HR = 3.56; P = 0.036) than higher DIPSS categories (HR = 2.07; P = 0.023). MF patients with CKD should be candidates for active management aimed at the improvement of renal function. Prospective studies defining the optimal therapeutic approach are highly needed.

C reactive protein to albumin ratio as prognostic marker in primary and secondary myelofibrosis

We retrospectively investigated C reactive protein to albumin ratio (CAR) in a cohort of 142 patients with myelofibrosis [101 primary (PMF); 41 secondary (SMF)] and compared it to hematological and clinical parameters. Among other associations, higher CAR was significantly associated with higher grade of bone marrow fibrosis, lower frequency of Calreticulin (CALR) mutations, presence of constitutional symptoms, massive splenomegaly, transfusion dependency, blast phase disease, lower hemoglobin, lower platelets, higher ferritin and higher lactate dehydrogenase (LDH) (p < .05 for all analyses). Higher CAR was able to predict inferior survival in PMF independently of DIPSS [hazard ratio (HR)=2.17; p = .015 for high CAR and HR = 2.05; p < .001 for DIPSS] and in SMF independently of Mysec-PM (HR = 6.48; p = .022 for high CAR and HR = 2.63; p = .013 for Mysec-PM) demonstrating its good prognostic potential. CAR seems to be an independent and prognostically relevant parameter, both in PMF and SMF, and might aid in timely recognition of most vulnerable patients.

Chronic kidney disease could be a risk factor for thrombosis in essential thrombocythemia and polycythemia vera

Chronic kidney disease (CKD) is a well-known risk factor for venous thromboembolism and cardiovascular (CV) disease development in the general population, but its role in thrombotic risk in essential thrombocythemia (ET) and polycythemia vera (PV) remains poorly understood. This retrospective multicenter study analyzed clinical correlations and the potential impact of CKD on thrombosis development in ET and PV patients. We included 167 patients (76 ET and 91 PV); 25.7% had CKD at diagnosis, defined as estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m² for ≥ 3 months. Lower eGFR correlated with advanced age, female sex, higher granulocytes, higher serum C-reactive protein, history of thrombosis, CV risk factors, and the presence of palpable splenomegaly. CKD was univariately associated with inferior thrombosis-free survival in the entire cohort, as well as in both ET and PV patients. These results remained significant in the multivariate Cox regression models when adjusted to disease-specific risk models. Therefore, CKD could be a risk factor for thrombosis in ET and PV patients. Additional studies on a larger number of patients are needed to confirm our findings and to elucidate whether the addition of CKD to the current risk stratification models might improve prognostication in ET and PV patients.

Serum chitotriosidase: a circulating biomarker in polycythemia vera

OBJECTIVES

Serum chitotriosidase activity (CHIT1) is a biomarker of macrophage activation with an important role in inflammation-induced tissue remodeling and fibrosis. Macrophages have been described to play a crucial role in regulating pathological erythropoiesis in polycythemia vera (PV). The aim of this study was to evaluate CHIT1 in patients diagnosed with Philadelphia-negative myeloproliferative neoplasms (MPNs).

METHODS

Using fluorometric assay, we measured CHIT1 in 28 PV, 27 essential thrombocythemia (ET), 17 primary myelofibrosis (PMF), 19 patients with secondary myelofibrosis and in 25 healthy controls.

RESULTS

CHIT1 was significantly higher in PV (p < .001) and post-PV myelofibrosis (MF) transformation (post-PV MF) (p = .020), but not in ET (p = .080), post-ET MF transformation (p = .086), and PMF patients (p = .287), when compared to healthy controls. CHIT1 in PV was positively correlated with hemoglobin (p = .026), hematocrit (p = .012), absolute basophil count (p = .030) and the presence of reticulin fibrosis in the bone marrow (p = .023).

DISCUSSION

A positive correlation between CHIT1 and these distinct laboratory PV features might imply macrophages closely related to clonal erythropoiesis as cells of CHIT1 origin. In addition, a positive association between CHIT1 and reticulin fibrosis might indicate its potential role in PV progression.

CONCLUSION

CHIT1 might be considered as a circulating biomarker in PV. Additional studies are needed to clarify the role of CHIT1 in promoting disease progression and bone marrow fibrosis in PV.

Death caused by possible unrecognized (too Late Recognized) Mycobacterium gordonae infection in a patient with angioimmunoblastic T-cell lymphoma

Here, we present possible death caused by Mycobacterium gordonae infection in a patient with angioimmunoblastic T-cell lymphoma. Our patient was severely immunocompromised in whom we suspect to an infection, but we did not have isolates until she died. After she died, we received a positive sputum culture of M. gordonae. We conclude that when having severely immunocompromised patients with suspicion of infection but without isolates we should always consider the saprophytic mycobacteria. These mycobacteria require a long period of isolation, but patients with these mycobacteria are potentially curable if appropriate treatment is applied for a sufficiently long period.

Neuroendocrine tumor of cecum in patient treated with imatinib mesylate for blastic phase of chronic myeloid leukemia

Imatinib mesylate (IM), a tyrosine kinase inhibitor, is the treatment of choice in patients with chronic myeloid leukemia (CML). It is considered a very safe drug, with mostly mild and reversible side effects. Lately, it has been suggested that adverse events may occur after a long term. We report a case of a 72-year-old woman diagnosed with blastic phase of Philadelphia chromosome positive CML treated with IM for 28 months. The patient presented first with ascites as a side effect of the drug. When the ascites re-occurred, it was caused by neuroendocrine tumor (NET) with peritoneal carcinomatosis. We believe this is the first case of a NET as a secondary malignancy (SM) after IM treatment. SM have been described in patients on IM before. It is unclear whether these tumors are caused by imatinib or found more easily because of close follow-up.

Leuconostoc sp. Meningitis in a Patient Treated with Rituximab for Mantle Cell Lymphoma

We present a 64-year-old man who was treated with R-CHOP (rituximab plus cyclophosphamide, doxorubicin, vincristine, and prednisolone) chemoimmunotherapy for mantle cell lymphoma and developed purulent meningitis, probably caused by Leuconostoc sp. The patient had severe hypogammaglobulinemia, which is a possible complication of rituximab therapy. To our knowledge and after reviewing the available medical literature, this is the first described case of purulent meningitis caused by Leuconostoc sp. in a patient with mantle cell lymphoma that appeared after treatment with the R-CHOP protocol. The diagnosis of purulent meningitis was based on clinical, laboratory and cytological cerebrospinal fluid findings, in addition to blood culture results in which we isolated Leuconostoc sp. The patient was treated with meropenem with full recovery.

Venous thromboembolism in Croatia - Croatian Cooperative Group for Hematologic Diseases (CROHEM) study

Aim

To analyze the incidence and characteristics of venous thromboembolism (VTE) in Croatia.

Methods

The Croatian Cooperative Group for Hematologic Diseases conducted an observational non-interventional study in 2011. Medical records of patients with newly diagnosed VTE hospitalized in general hospitals in 4 Croatian counties (Šibenik-Knin, Koprivnica-Križevci, Brod-Posavina, and Varaždin County) were reviewed. According to 2011 Census, the population of these counties comprises 13.1% of the Croatian population.

Results

There were 663 patients with VTE; 408 (61.54%) had deep vein thrombosis, 219 (33.03%) had pulmonary embolism, and 36 (5.43%) had both conditions. Median age was 71 years, 290 (43.7%) were men and 373 (56.3%) women. Secondary VTE was found in 57.3% of participants, idiopathic VTE in 42.7%, and recurrent VTE in 11.9%. There were no differences between patients with secondary VTE and patients with idiopathic VTE in disease recurrence and sex. The most frequent causes of secondary VTE were cancer (40.8%), and trauma, surgery, and immobilization (38.2%), while 42.9% patients with secondary VTE had ≥2 causes. There were 8.9% patients ≤45 years; 3.3% with idiopathic or recurrent VTE. Seventy patients (10.6%) died, more of whom had secondary (81.4%) than idiopathic (18.6%) VTE (P < 0.001), and in 50.0% VTE was the main cause of death. Estimated incidence of VTE in Croatia was 1.185 per 1000 people.

Conclusion

Characteristics of VTE in Croatia are similar to those reported in large international studies. Improved thromboprophylaxis during the presence of risk factors for secondary VTE might substantially lower the VTE burden.