Splanchnic vein thrombosis as a manifestation of latent myeloproliferative neoplasm associated with sticky platelet syndrome / Trombosis esplácnica como presentación de neoplasia mieloproliferativa latente asociada con síndrome de plaqueta pegajosa

Abstract Vein thrombosis of unusual sites such as the splanchnic region continues to be not only a diagnostic but also a therapeutic challenge for the clinician due to its manifestation and associated pathologies. Latent JAK2 (Janus kinase 2) positive myeloproliferative neoplasm associated with sticky platelet syndrome is unusual. We present a clinical case of a 38-year-old female patient who presented with sudden onset abdominal pain of a possible vascular origin. Splanchnic thrombosis was diagnosed in latent myeloproliferative neoplasm by identifying the JAK2V617F mutation and sticky platelet syndrome via platelet aggregometry. Off-label anticoagulation with rivaroxaban 20 mg/day was administered. During her outpatient follow-up, she did not suffer any new thrombotic episodes.

Resumen La trombosis venosa de sitios inusuales como la esplácnica continúa siendo un reto no solo diagnóstico sino también terapéutico para el clínico debido a su forma de presentación y las patologías asociadas. La neoplasia mieloproliferativa latente JAK2 (cinasa de Janus 2) positiva asociada con síndrome de plaqueta pegajosa es inusual. Se presenta un caso clínico de una paciente de 38 años de edad que debutó con dolor abdominal de inicio súbito que sugirió un posible origen vascular. Se diagnosticó trombosis esplácnica en relación con neoplasia mieloproliferativa latente por la identificación de la mutación de la JAK2V617F y síndrome de plaqueta pegajosa mediante agregometría plaquetaria. Se administró de manera off-label anticoagulación con rivaroxabán 20 mg/día. Durante su seguimiento ambulatorio no ha presentado nuevos episodios trombóticos.

Trastornos mieloproliferativos y leucemia en síndrome de Down. Presentación de dos casos clínicos en el período neonatal / Myeloproliferative disorders and leukemia related to Down syndrome. Report of two clinical cases in neonatal period

ElsíndromedeDownpredisponeatrastornosmieloproliferativos. Se estima que del 5 % al 30 % de los neonatos con esta condición desarrollarán mielopoyesis anormal transitoria. El tratamiento no está estandarizado; la exanguinotransfusión y la citarabina podrían ser efectivos. Se describen dos casos de pacientes con síndrome de Down, quienes durante el período neonatal presentaron leucemia mieloide aguda y mielopoyesis anormal transitoria, los tratamientos utilizados y sus desenlaces. Se considera que la sospecha y el diagnóstico temprano de esta entidad son factores determinantes en el pronóstico.

Down syndrome predisposes to haematological disorders. It is estimated that 5-30% of neonates with this condition will develop transient abnormal myelopoiesis. Treatment is not standardized; exchange transfusion and the use of cytarabine could be effective. We present two clinical cases of patients with Down syndrome, who during the neonatal period showed acute myeloid leukemia and transient abnormal myelopoiesis, the treatments used and their outcomes. Suspicion and early diagnosis of this entity are considered determining factors in prognosis.

Hepatic manifestations of hematological diseases / 中华肝脏病杂志

Liver involvement is often observed in hematological disorders, resulting in liver abnormality, including unconjugated hyperbilirubinemia, monoclonal hyperglobulinemia, portal vein, or hepatic vein thrombosis or portal hypertension, hepatosplenomegaly, or iron accumulation in the liver. Here we summarize the major hematological diseases that often affect the liver: hemolytic anemia, defect in coagulation or anti-coagulation factors, myeloproliferative neoplasm, hemophagocytic lymphohistiocytosis, multiple myeloma, leukemia, and lymphoma. We hope this review will help clinicians diagnose and manage the patients with liver involvement by hematological disorders.

Utilidad diagnóstica de la biopsia de médula ósea en pediatría / Diagnostic utility of biopsy of bone marrow in Pediatry

La biopsia de médula ósea (BMO) es un procedimiento invasivo que ha ganado campo en la práctica médica ya que se realiza para el diagnóstico, estadificación y seguimiento de enfermedades hematológicas y no hematológicas, benignas o neoplásicas, entre otros. El objetivo fue establecer el rol de la BMO en las hemopatías en Pediatría en el ION SOLCA Guayaquil- Ecuador. Se utilizó un estudio descriptivo retrospectivo donde se incluyeron a todos los pacientes pediátricos menores de 18 años de edad que se sometieron a BMO, desde Julio de 2014 a Julio de 2017 en el hospital. De las 1511 BMO realizadas en el periodo de estudio, 869 correspondieron a biopsias pediátricas, de las cuales el 57,08% fueron varones. La edad mediana fue 5 (RIC: 3-10) años. El tamaño promedio de la BMO fue de 0,74 (0,1-2,5) cm, con una celularidad media de 20% (4-100%). El motivo de consulta más frecuente fue la fiebre (22,67%). En el hemograma se detectó más frecuentemente bicitopenia (44,65%) y pancitopenia (24,63%). La Leucemia Linfoblástica Aguda (LLA) fue la enfermedad hematológica maligna más comúnmente encontrada (19,59%). Solo un 0,12% correspondió al grupo de Síndromes Mielodisplásicos (SMD), mientras que un 0,23% fueron Neoplasias Mieloproliferativas (NMP). El 26,93% de las biopsias no fueron aptas para el diagnóstico, el 48,45% se encontraron libres de enfermedad de base. La enfermedad oncohematológica pediátrica más frecuente es la LLA, mientras que los SMD y las NMP son infrecuentes. El rol del patólogo y de la BMO es fundamental en el diagnóstico de las enfermedades hematológicas, siempre en integración con la clínica y los exámenes complementarios.

Bone marrow biopsy (BMB) is an invasive procedure that has gained ground in medical practice since it is performed for the diagnosis, staging and monitoring of hematological and non-hematological, benign or neoplastic diseases, among others. This work aims to establish the role of the BMB in hematological diseases in Pediatrics in the ION SOLCA Guayaquil ­ Ecuador. A non-experimental design study, descriptive type was used, that included all pediatric patients under 18 years of age who submitted a BMB, from July 2014 to July 2017 in the hospital. Of the 1511 BMB performed in the study period, 869 corresponded to pediatric biopsies, of which 57.08% belong to male patients. The median age was 5 (interquartile range: 3 - 10) years. The average size of the BMB was 0.74 (0.1 - 2.5) cm, with an average cellularity of 20% (4 - 100%). The most frequent reason for consultation was fever (22.67%). In the complete blood count, bicytopenia (44.65%) and pancytopenia (24.63%) were detected most commonly. Acute Lymphoblastic Leukemia (ALL) was the most frequent malignant hematologic disease (19.59%). Only 0.12% corresponded to the group of Myelodysplastic Syndromes (MDS), while 0.23% were Myeloproliferative Neoplasms (MPN). 26.93% of the biopsies were not apt for diagnosis, 48.45% were free of base disease. The most cfrequent pediatric onco-hematologic disease is ALL, while MDS and MPN are infrequent. The role of the pathologist and the BMP is fundamental in the diagnosis of hematological diseases, always in integration with the clinic and complementary examinations.

Características otorrinolaringológicas en niños con trisomía 21: un estudio de 171 pacientes en el Hospital Infantil de México Federico Gómez / Otolaryngological features in children with trisomy 21: a study of 171 patients at the Hospital Infantil de México Federico Gómez

Resumen Introducción: Los niños con trisomía 21 enfrentan una amplia gama de problemas en la región de la cabeza y el cuello, por lo cual es importante reconocer las manifestaciones otorrinolaringológicas que presentan, así como su apropiado manejo. Métodos: Estudio de serie de casos retrospectivo de pacientes pediátricos con trisomía 21. De cada caso se analizó el espectro de manifestaciones otorrinolaringológicas, el manejo establecido y los resultados. Resultados: Se incluyeron 171 niños. La edad media de la primera valoración por otorrinolaringología en la institución fue de 7.2 ± 4.2 años. Las manifestaciones otológicas más frecuentes fueron la estenosis del conducto auditivo externo y la disfunción de la trompa de Eustaquio. Más de la mitad de los pacientes (63 %) presentaron hipoacusia, principalmente de tipo conductivo bilateral, y hasta el 75 % de los pacientes con afectación otológica requirieron algún procedimiento quirúrgico. Las manifestaciones rinológicas más comunes fueron la rinosinusitis crónica y la rinitis alérgica. La apnea obstructiva del sueño estuvo presente en el 30% de los pacientes. El tratamiento principal fue la amigdalectomía, seguida del tratamiento con dispositivos de presión positiva de la vía aérea. Menos del 5 % de los pacientes presentaron un compromiso laríngeo. Conclusiones: Los pacientes pediátricos con trisomía 21 deben ser remitidos sistemáticamente a una evaluación otorrinolaringológica periódica, debido a la alta incidencia de manifestaciones en esta región. Se deben ofrecer tratamientos oportunos para mejorar su salud y calidad de vida.

Abstract Introduction: Children with trisomy 21 face a wide range of conditions in the head and neck region, for which it is important that physicians are aware and have a strong understanding of the ear, nose, and throat (ENT) disorders, and their management as well. Methods: Retrospective case series of pediatric patients with trisomy 21. The spectrum of otolaryngological manifestations, their management, and outcomes of each case were analysed. Results: One hundred and seventeen pediatric patients were included. The mean age was 7.2 ± 4.2 years. More than half of the patients (63 %) had hearing loss (HL). The most frequent presentation was conductive HL, predominating the mild and bilateral type. The most common otological manifestations found were external ear canal stenosis and Eustachian tube dysfunction. Up to 75 % of the patients with otologic involvement required some surgical procedure. The most common rhinological manifestations were chronic rhinosinusitis and allergic rhinitis. Obstructive sleep apnea (OSA) was present in 30% of all patients, which main treatment was tonsillectomy, followed by continuous positive and biphasic positive airway pressure treatments. Less than 5 % of the patients presented a laryngeal compromise. Conclusions: Pediatric patients with trisomy 21 systematically should be referred to periodic ENT assessment due to the high incidence of manifestations in this region. Timely treatments should be offered in order to improve the health and the quality of life of the patient.

Estandarización de la técnica Real Time PCR para la detección molecular de la mutación V617F en el gen de JAK-2 en neoplasias mieloproliferativas crónicas / Standardization of the Real Time PCR technique for the molecular detection of the V617F mutation in the JAK-2 gene in chronic myeloproliferative neoplasms

V617F mutation in exon 14 of Janus Kinase 2 gene (jak-2) is used as a molecular marker for the diagnosis of Philadelphia negative myeloproliferative neoplasms (Phi-) such as Polycythemia Vera (PV), Essential Thrombocythemia (ET) and Primary Myelofibrosis (MFP). To detect this mutation, we used conventional polymerase chain reaction technique (PCR), a simple and inexpensive technique, however, has some drawbacks that current technology allows to solve. During the last years, more sensitive molecular techniques have been incorporated in clinical practice to support the diagnosis, prognosis and follow-up of hematological patients. For its implementation in the clinical routine should be considered technical and economic aspects, so in this work, we evaluate the Real Time PCR technique as a diagnostic method for the detection of the Jak-2-V617F mutation, using in house primers design. Our result show that the technique implemented has a concordance index of 0.87 with the conventional PCR used in the molecular diagnosis of myeloproliferative neoplasms. In addition, it has the same specificity, greater sensitivity and, shorter execution time in relation to conventional PCR. The implementation of this diagnostic method in our Hospital is technically possible and commercially convenient. (AU)

Pre-analytical parameters associated with unsuccessful karyotyping in myeloid neoplasm: a study of 421 samples

Cytogenetics is essential in myeloid neoplasms (MN) and pre-analytical variables are important for karyotyping. We assessed the relationship between pre-analytical variables (time from collection to sample processing, material type, sample cellularity, and diagnosis) and failures of karyotyping. Bone marrow (BM, n=352) and peripheral blood (PB, n=69) samples were analyzed from acute myeloid leukemia (n=113), myelodysplastic syndromes (n=73), myelodysplastic syndromes/myeloproliferative neoplasms (n=17), myeloproliferative neoplasms (n=137), and other with conclusive diagnosis (n=6), and reactive disorders/no conclusive diagnosis (n=75). The rate of unsuccessful karyotyping was 18.5% and was associated with the use of PB and a low number of nucleated cells (≤7×103/µL) in the sample. High and low cellularity in BM and high and low cellularity in PB samples showed no metaphases in 3.9, 39.7, 41.9, and 84.6% of cases, respectively. Collecting a good BM sample is the key for the success of karyotyping in MN and avoids the use of expensive molecular techniques.

Supervivencia a largo plazo de pacientes con síndromes mieloproliferativos crónicos filadelfia negativos y su relación con variables clínico-patológicas

RESUMEN: Los sindromes mieloproliferativos crónicos (SMP) Filadelfia negativosclásicos incluyen tres neoplasias hematológicas caracterizadas por exceso deproliferación de progenitores del linaje mieloide: policitemia vera (PV),trombocitemia esencial (TE) y mielofibrosis primaria (MFP).En el presente estudio multicéntrico y prospectivo se incluyeron 102pacientes con diagnóstico de SMP con el objetivo de estudiar variables clínicas ypatológicas asociadas con supervivencia a largo plazo. Al momento de la inclusiónse estudió la presencia de la mutación V617F del gen JAK2 y otras mutaciones delgen JAK2. En una mediana de seguimiento de 11,5 años, se registraron eventostrombóticos, hemorrágicos, progresión hematológica y otros tumores primarios.Los resultados obtenidos demostraron que los pacientes positivos para lamutación JAK2V617F tuvieron mayor edad, mayor prevalencia de hipertensiónarterial, mayor valor de glóbulos blancos y fosfatasa alcalina leucocitaria. Lamutación se asoció a mayor riesgo de trombosis y ello se trasladó a unasupervivencia libre de eventos trombóticos inferior para los pacientes JAK2V617Fpositivos. La incidencia de transformación fibrótica a 10 años para los pacientes conPV y TE fue de 5,9%. La incidencia de progresión a mielodisplasia y leucemia agudapara todos los pacientes fue de 2,5% a 10 años. Para todos los pacientes la edadmayor o igual a 60 años se asoció a inferior supervivencia global y en pacientes conPV también la trombosis arterial. Se demostró que las causas de muerte de estospacientes no sólo estuvieron relacionadas a la progresión de la malignidad primariasino también a causas no malignas (eventos cardiovasculares) o malignidadessecundarias no hematológicas.En conclusión, los SMP Filadelfia negativos son patologías complejas deevolución variable. Los datos obtenidos en este trabajo y las asociacionesencontradas permitirán mejorar las estrategias de seguimiento y tratamiento deestos pacientes.

SUMMARY: Philadelphia chromosome-negative chronic myeloproliferative neoplasms(MPN) are hematological malignancies characterized by excessive proliferation ofmyeloid progenitor cells. The three classical entities are: polycythemia vera (PV),essential thrombocythemia (ET) and primary mielofibrosis (PMF).In this multicenter and prospective study 102 patients with diagnosis ofclassical MPN were included. The purpose of this study was to analyze the impact ofclinical and pathological variable on long-term survival. At inclusion, JAK2V617F andothers JAK2 mutations were studied in all patients. In a median of follow-up of 11.5years, vascular events, hematological progression and others primary tumors wereregistered.The results showed that JAK2V617F mutation positive patients were olderand had a higher rate of arterial hypertension, white cell counts, and alkalinephosphatase score. JAK2V61F was associated with a higher risk of thrombosis and alower thrombotic event free survival. The 10-year cumulative incidence of fibrotictransformation for patients with PV and ET was 5.9% and the 10-year cumulativeincidence of myelodysplasia and leukemia transformation was 2.5%. For all patients,age equal or more than 60 years old was associated with inferior overall survival; inpatients with PV also the arterial thrombosis affected the overall survival. Causes ofdeath of this cohort were related not only to the progression of hematologicalmalignancy but also to vascular events and others primary tumors.In conclusion MPN are complex diseases with variable clinical outcome. Thepresent study offers important insights about the natural history of this group ofmalignancies and provides information for developing treatment and follow-upstrategies.

Straightforward Identification of Masked Polycythemia Vera Based on Proposed Revision of World Health Organization Diagnostic Criteria for BCR-ABL1-Negative Myeloproliferative Neoplasms

No abstract available.

Calreticulin Exon 9 Mutations in Myeloproliferative Neoplasms

BACKGROUND: Calreticulin (CALR) mutations were recently discovered in patients with myeloproliferative neoplasms (MPNs). We studied the frequency and type of CALR mutations and their hematological characteristics. METHODS: A total of 168 MPN patients (36 polycythemia vera [PV], 114 essential thrombocythemia [ET], and 18 primary myelofibrosis [PMF] cases) were included in the study. CALR mutation was analyzed by the direct sequencing method. RESULTS: CALR mutations were detected in 21.9% of ET and 16.7% of PMF patients, which accounted for 58.5% and 33.3% of ET and PMF patients without Janus kinase 2 (JAK2) or myeloproliferative leukemia virus oncogenes (MPL) mutations, respectively. A total of five types of mutation were detected, among which, L367fs*46 (53.6%) and K385fs*47 (35.7%) were found to be the most common. ET patients with CALR mutation had lower leukocyte counts and ages compared with JAK2-mutated ET patients. CONCLUSION: Genotyping for CALR could be a useful diagnostic tool for JAK2-or MPL-negative ET or PMF patients. CALR mutation may be a distinct disease group, with different hematological characteristics than that of JAK2-positive patients.

Guidelines for the management of myeloproliferative neoplasms

Polycythemia vera, essential thrombocythemia, and primary myelofibrosis are collectively known as 'Philadelphia-negative classical myeloproliferative neoplasms (MPNs).' The discovery of new genetic aberrations such as Janus kinase 2 (JAK2) have enhanced our understanding of the pathophysiology of MPNs. Currently, the JAK2 mutation is not only a standard criterion for diagnosis but is also a new target for drug development. The JAK1/2 inhibitor, ruxolitinib, was the first JAK inhibitor approved for patients with intermediate- to high-risk myelofibrosis and its effects in improving symptoms and survival benefits were demonstrated by randomized controlled trials. In 2011, the Korean Society of Hematology MPN Working Party devised diagnostic and therapeutic guidelines for Korean MPN patients. Subsequently, other genetic mutations have been discovered and many kinds of new drugs are now under clinical investigation. In view of recent developments, we have revised the guidelines for the diagnosis and management of MPN based on published evidence and the experiences of the expert panel. Here we describe the epidemiology, new genetic mutations, and novel therapeutic options as well as diagnostic criteria and standard treatment strategies for MPN patients in Korea.

Transient myeloproliferative disorder and Down Syndrome. Is there a link?

An extremely premature male neonate presented with an unusual multisystem dysfunction within the first 24 to 48 hours of life. The unfolding of clinical events and investigations revealed a transient myeloproliferative disorder [TMD]. TMD was the main indication for karyotyping of this premature infant without clinical symptoms of Down syndrome. The awareness of TMD in a newborn warrants karyotype analysis to look for trisomy 21 and a close surveillance because of its potential progression to true leukaemia

Reacciones leucemoides en el recién nacido / Leukemoid reactions in the newborn

Presentamos el caso de una recién nacida prematura y de bajo peso al nacer que desarrolló cuentas leucocitarias elevadas hasta más de 100,000 x mmc, sin otras anormalidades hematológicas y que resolvió espontáneamente. A propósito del caso se revisó las ca usas de reacciones leucemoides en el período neonatal. En primer lugar la causa más conocida: síndrome míeloprollferatlvo transitorio, descrito en trisomía 21. En pacientes sin anomalías cromosómicas el uso de esteroides para inducir la maduración pulmonar , la corioamnlonitls y la prematurez extrema son exploradas como causas de RL. Luego revisamos el desarrollo de dlsplasia broncopulmonar y el síndrome de respuesta inflamatoria slstémlca en relación a RL...(AU)

JAK2 V617F and Exon 12 Genetic Variations in Korean Patients with BCR/ABL1-negative Myeloproliferative Neoplasms / 대한진단검사의학회지

BACKGROUND: JAK2 genetic variations have been described in a high proportion of patients with BCR/ABL1-negative myeloproliferative neoplasms (MPN). This study was designed to analyze the frequencies of JAK2 V617F and exon 12 variations, and their correlations with clinical characteristics of Korean patients with BCR/ABL1-negative MPN. METHODS: We examined a total of 154 patients with BCR/ABL1-negative MPN that included 24, 26, 89, and 15 patients with polycythemia vera (PV), primary myelofibrosis (PMF), essential thrombocythemia (ET), and unclassified myeloproliferative neoplasms (MPNU), respectively. We performed allele-specific PCR to detect V617F in all BCR/ABL1-negative patients, and performed direct sequencing to detect exon 12 variations in 47 V617F-negative MPN patients. JAK2 c.1641+179_183del5 variation was detected by restriction fragment length polymorphism assay in 176 healthy subjects. RESULTS: JAK2 V617F was detected in 91 patients (59.1%): PV (91.6%), PMF (46.2%), ET (52.8%), and MPNU (66.7%). In V617F-negative MPN patients, no mutations were found in exon 12. The c.1641+179_183del5 was detected in 68.1% of V617F-negative MPN patients and 45.4% of healthy subjects (P=0.008). JAK2 V617F was closely correlated with age and leukocytosis in BCR/ABL1-negative MPN patients (P<0.05). However, c.1641+179_183del5 was not related to age, sex, or complete blood cell count parameters in V617F-negative MPN patients and healthy subjects. The c.1641+179_183del5 was associated with an increased odds ratio for MPN (odds ratio, 2.6; 95% confidences interval, 1.3-5.1; P=0.007). CONCLUSIONS: Frequencies of V617F are similar to reported results. JAK2 exon 12 mutations may be rare and c.1641+179_183del5 may influence the occurrence of MPN in Korean patients with V6 17F-negative MPN.

Usefulness of Real-time Semi-quantitative PCR, JAK2 MutaScreen (TM) Kit for JAK2 V617F Screening / 대한진단검사의학회지

BACKGROUND: Real-time PCR for quantification of JAK2 V617F has recently been introduced and used to evaluate the importance of mutant allele burden in both diagnosis and disease progression in myeloproliferative diseases (MPDs). We evaluated the usefulness of JAK2 MutaScreen(TM) kit that uses a real-time semiquantitative PCR method and has been designed to screen JAK2 V617F mutant allele burden. METHODS: Forty MPD patients were included in this study. We screened JAK2 V617F and determined the mutant allele burden using JAK2 MutaScreen(TM) kit. The mutant allele burden was estimated by six-scaled standards of JAK2 V617F mutant allele (2%, 5%, 12.5%, 31%, 50%, and 78%). For evaluation of test performance, an allele-specific PCR (AS-PCR) was carried out in all samples by using Seeplex JAK2 Genotyping kit. We assessed the clinical differences in distinct disease entities of MPDs according to JAK2 V617F mutant allele burden. RESULTS: JAK2 V617F mutation was detected in 30 cases, including 10 of 11 cases (91%) of polycythemia vera (PV), 13 of 20 cases (65%) of essential thrombocythemia (ET), and 2 of 3 cases (67%) of chronic idiopathic myelofibrosis (CIMF). The concordance rate between the two tests was 95% (38/40). JAK2 V617F mutant allele burden was greater than 50% in 17 cases, and 10 of them (59%) were PV. In contrast, mutant allele burden was less than 50% in 13 cases and 11 of them (85%) were ET. CONCLUSIONS: JAK2 MutaScreen(TM) kit that utilizes a real-time semi-quantitative PCR method is a useful tool for diagnosing MPDs precisely. It can be used to assess the grade of mutant allele burden as well as to screen JAK2 V617F simultaneously.

Clinical applications of molecular haematology: flow cytometry in leukaemias and myelodysplastic syndromes.

Flow cytometry is semi-automated study of antigen profile of cells using the Scatchard principle of antigen-antibody binding and fluorochrome-based detection systems. Flow cytometric evaluation of cellular proteomics has become an integral part of the laboratory diagnosis and classification of haematopoietic neoplasms. Recent technical advances in lasers, monoclonal antibodies, fluorochromes, and computer-based color compensation algorithms have expanded the usefulness of flow cytometry. Detection of minimal residual disease by flow cytometry in leukaemias and lymphomas is incorporated in many treatment protocols. Finding of aberrant maturation pattern of granulocytes offers a sensitive screening tool for early diagnosis of myelodysplastic syndromes. Detailed proteomic analysis of leukemias is helping more precise prognostic and biological stratification.

Thrombocytosis: age dependent aetiology and analysis of platelet indices for differential diagnosis.

To identify the etiology of thrombocytosis in various age groups and to evaluate the effectiveness of platelet indices in differentiating reactive and clonal thrombocytosis, an observational, prospective review of patients with platelet count of 600 x 10(9)/L or more performed by using coulter counter STKS (Coulter Electronic, Kerfeld, Germany). Extreme thrombocytosis defined as platelet count of 1000 x 10(9)/L or more. Of 1068 patients, 91.8% had reactive and 8.2% had clonal thrombocytosis. Frequent causes of reactive thrombocytosis were infections (44.9%), tissue injury (11.4%) and rebound thrombocytosis (10.2%). Fifty-five patients had extreme thrombocytosis, main aetiologies were secondary and clonal thrombocytosis that seen in 72.7% and 27.3% of cases respectively. Comparison of platelet indices showed; that cases with reactive thrombocytosis had low mean platelet volume and platelet distribution width. We concluded that thrombocytosis could be a response to various physiological and pathological processes. Low MPV and PDW in patients with high platelet counts strongly suggest reactive etiology.

Clinical applications of molecular haematology: an overview.

Haematological disorders are getting more and more molecularly defined. This is specially so in the field of haematological malignancies. The molecular understanding has helped in fine-tuning the diagnosis, prognosis and management. The tests are becoming widely available and they enjoy both sensitivity and specificity. Following is an overview of clinical applications of molecular haematology, especially in the field of chronic myeloid leukaemia, chronic eosinophilic leukaemia, bcr abl negative chronic myeloproliferative disorders and acute promyelocytic leukaemia.

Diagnostic Usefulness of the Janus Kinase 2 Mutation in non BCR/ABL Myeloproliferative Disorders

BACKGROUND: We investigated the Janus kinase 2 (JAK2) mutation and its diagnostic value in patients suffering with non BCR/ABL myeloproliferative diseases (nMPD) or other reactive conditions. METHODS: We reviewed the clinical records of 83 patients who underwent bone marrow (BM) examinations with suspect of nMPD. The diagnoses of nMPD were made based on the WHO criteria since 2001 and the PVSG criteria before 2001. The JAK2 mutation was examined by PCR in 54 patients whose BM samples were available. RESULTS: The JAK2 mutation was detected in 25 patients (46%); 12 of 26 patients with essential thrombocythemia (ET), 9 of 12 patients with polycyhtemia vera (PV), one of 7 patients with chronic idiopathic myelofibrosis (CIM) and one patient with unclassifiable MPD. Additionally, JAK2 mutation was detected in each one patient with secondary polycythemia and reactive thrombocytosis. These two patients and two other patients among the JAK2 mutated ET did not meet the WHO PV criteria due to their initial low hemoglobin levels. These patients had liver cirrhosis and hypersplenism due to Budd-Chiari syndrome (1), gastrointestinal bleeding (1) or the initial hemoglobin level was slightly below the level as provided by the criteria, but the level showed a rising pattern despite cytoreductive therapy (2). With the results of the JAK2 mutation available, 4 patients' disease could be re-diagnosed as PV. Finally, the positive rate of the JAK2 mutation was 81% in PV, 48% in ET and 14% in CIM. The presence of JAK2 mutation closely correlated with PV (p=0.001), leukocytosis (p=0.001) and an increased cellularity of BM (p=0.024). CONCLUSIONS: The JAK2 mutation may help differentiate nMPD from secondary cytosis. Therefore, it should be incorporated into the guidelines for the nMPD work-up for making a more accurate diagnosis and administering proper treatment.