REFRACTORY GUILLAIN-BARRÉ SYNDROME IN A PATIENT WITH ASYMPTOMATIC MULTIPLE MYELOMA SUCCESSFULLY TREATED WITH LOW-DOSE RITUXIMAB.

Despite being extremely rare, Guillain-Barré syndrome (GBS) has been recognized as a neurological complication of multiple myeloma, with variable responses to plasmapheresis (PEX), intravenous immunoglobulins (IVIG), and anti-myeloma therapies. In this paper, we report a case of a female patient with asymptomatic multiple myeloma (aMM) who initially presented as PEX- and IVIG-refractory GBS. After failure of PEX, IVIG, and anti-myeloma therapy (bortezomib, melphalan, and prednisone), the patient was eventually successfully treated with low-dose rituximab (100 mg/m2 per week in four doses). To the best of our knowledge, this is the first case to report successful treatment of refractory GBS potentially associated to aMM with low-dose rituximab. Additional studies are needed to elucidate the pathophysiological processes and the interplay between the dysregulated immune response, monoclonal immunoglobulin (MG), and neural tissue damage in GBS patients. Also, the potential role of rituximab in the treatment of MG-associated GBS warrants further exploration.

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 (Sibenik-Knin, Koprivnica-Krizevci, Brod-Posavina, and Varazdin 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.

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.

Hematocrit to hemoglobin ratio as a prognostic marker in polycythemia vera.

BACKGROUND: The hematocrit to hemoglobin ratio (HHR) is frequently used in everyday practice to measure hemoconcentration; however, clinical associations of HHR in the context of polycythemia vera (PV) have not been investigated so far. PATIENTS AND METHODS: We retrospectively assessed HHR at the time of diagnosis in 107 PV and 40 secondary polycythemia (SP) patients from three community hospitals. RESULTS: Median HHR was higher in PV than in SP patients (3.131 vs. 2.975, p = 0.041). Among PV patients, higher HHR correlated with splenomegaly, higher total leukocyte and absolute granulocyte counts, higher red blood cell counts, lower hemoglobin, higher red blood cell distribution width, lower mean corpuscular hemoglobin and lower ferritin levels, whereas in SP patients higher HHR correlated with older age, female sex and lower hemoglobin (p < 0.050 for all analyses). Using the receiver operating curve analysis-defined cut-off points, higher HHR in PV was associated with a shorter time to thrombosis (hazard ratio-HR 5.20, p = 0.022) independently of high-risk disease status (HR 4.48, p = 0.034) and shorter overall survival (HR 6.69, p = 0.009) independently of leukocytosis (HR 4.48, P = 0.034) and the absence of aspirin use (HR 15.53, p < 0.001). CONCLUSION: Higher HHR may represent iron deficiency and a stronger clonal myeloproliferation in PV and could provide additional prognostic information to the classical risk assessment.

Serum procalcitonin in Philadelphia-negative myeloproliferative neoplasms.

Philadelphia-negative myeloproliferative neoplasms (MPNs), essential thrombocythemia (ET), polycythemia vera (PV), and myelofibrosis (MF), are rare clonal hematopoietic stem cell disorders accompanied by a strong inflammatory milieu, which is directly responsible for constitutional symptoms associated with the disease, such as fever, weight loss or night sweats. Non-hematologists sometimes (and often wrongly) consider the fever in MPN patients to be a symptom of an underlying disease, which may have devastating consequences. Serum procalcitonin (PCT) is a circulating biomarker commonly used to improve the diagnostic accuracy of bacterial infections and to guide antibiotic therapy. The aim of this study was to test whether PCT could aid the clinician in the early diagnosis of bacterial infections in MPNs. This study investigated PCT in 41 ambulatory MPN patients (13 ET, 13 PV and 15 MF) who had no signs of infection and compared it to 10 MPN patients with microbiologically and/or serologically documented bacterial infections. Median PCT in MPN patients was 0.02 ng/mL (range 0.01-0.09 ng/mL). No difference in PCT was found between ET, PV and MF patients (p = 0.993), whereas MPN patients with documented bacterial infections had significantly higher PCT (median PCT 2.45, range 0.90-5.40 ng/mL) when compared to MPN patients with (median PCT 0.03 ng/mL) or without constitutional symptoms (median PCT 0.02 ng/mL; p < 0.001 for both analyses). These results clearly show that PCT should not be considered as a disease biomarker in MPNs and careful clinical assessment for the signs of infection is needed when MPN patients present with fever and high PCT.

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.

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 ACE­i 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 ACE­i 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), ACE­i (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. ACE­i (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 ACE­i 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.

[Diagnosis and therapy for patients with essential thrombocythemia. Guidelines of Croatian Cooperative Group for hematologic disorders--KROHEM]. / Dijagnosticko-terapijski pristup u bolesnika s esencijalnom trombocitemijom. Smjernice Hrvatske kooperativne grupe za hematoloske bolesti--KROHEM.

Essential thrombocythemia (ET) is a clonal myeloproliferative neoplasm. Croatian Cooperative Group for hematologic disorders, KROHEM proposes the diagnostic and treatment guidelines for ET. Diagnosis of ET is based on the criteria and classification of World Health Organization (WHO). The level of treatment recommendation is based on the UpToDate (web based medical community database) criteria. For ET diagnosis it is mandatory to show sustained increased number of platelets with typical histomorphological changes of megakaryopoiesis in bone marrow. Secondary thrombocytosis and other chronic myeloproliferative neoplasms have to be excluded. Therapy is based on risk factors for ET. The risk factors are number of platelets, patient's age, and the risk levels for thrombosis and bleeding. Patients with low risk (age < 60 years and platelets < 1000 x 10(9)/L) arw not candidates for therapy. In younger group of patients with platelets between 1000 and 1500 x 10(9)/L or more than 1500 x 10(9)/L treatment with anagrelide or hydroxyurea is recommended respectively. In high risk patients hydroxyurea is the first line treatment. Anagrelide is indicated in these patients in the absence of treatment response. Alpha-interferon is recommended for pregnant women with ET and high platelet counts.

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.

Coombs-positive refractory acquired thrombotic thrombocytopenic purpura in a patient with chronic myelomonocytic leukemia successfully treated with rituximab.

OBJECTIVES: Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare autoimmune disorder characterized by auto-antibodies to Willebrand factor (vWF) cleaving enzyme (ADAMTS13), resulting in unusually large vWF multimers that lead to platelet aggregation, microthrombi formation and microangiopathic hemolytic anemia. Hemolysis in aTTP is mechanical; thus, direct antiglobulin test (Coombs test) is usually negative. Multiple autoimmune conditions and various auto-antibodies have been described in the context of chronic myelomonocytic leukemia (CMML). In this paper, we describe the first case of CMML with auto-antibodies to ADAMTS13, presenting initially as plasmapheresis-refractory Coombs-positive aTTP. Results: Although our patient was not treated for CMML, a complete remission of aTTP was eventually achieved with rituximab. Conclusion; We propose that aTTP should be in the differential diagnosis of CMML patients with thrombocytopenia and anemia (Coombs positive or not) who develop signs of thrombotic microangiopathy. Further studies are much needed to decipher the immune-mediated processes in CMML.

Guidelines for Diagnosis and Treatment of Chronic Lymphocytic Leukemia. Krohem B-Cll 2017.

Recent developments in the diagnosis and treatment of chronic lymphocytic leukemia (B-CLL) have led to change of approach in clinical practice. New treatments have been approved based on the results of randomized multicenter trials for first line and for salvage therapy, and the results of numerous ongoing clinical trials are permanently providing new answers and further refining of therapeutic strategies. This is paralleled by substantial increase in understanding the disease genetics due to major advances in the next generation sequencing (NGS) technology. We define current position of the Croatian Cooperative Group for Hematologic Disease on diagnosis and treatment of CLL in the transition from chemo-immunotherapy paradigm into a new one that is based on new diagnostic stratification and unprecedented therapeutic results of B-cell receptor inhibitors (BRI) and Bcl-2 antagonists. This is a rapidly evolving field as a great number of ongoing clinical trials con-stantly accumulate and provide new knowledge. We believe that novel therapy research including genomic diagnosis is likely to offer new options that will eventually lead to time limited therapies without chemotherapy and more effective clinical care for B-CLL based on individualized precision medicine.

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.