Hemangioblastoma: An Uncommon Cause of Polycythemia in a Child.

Polycythemia is a rare condition in children. Myeloproliferative neoplasms, including polycythemia vera although rare, is an important cause of childhood primary polycythemia. Secondary polycythemia is more common in children due to conditions causing hypoxia or due to pathologic erythropoietin production in malignancies like renal cell carcinoma, Wilms tumor or Hepatocellular carcinoma. Central nervous system hemangioblastoma is one of the rare causes of polycythemia. We report a 13-year-old girl with primarily neurological symptoms identified to be polycythemic during routine evaluation. Clinical examination and neuroimaging subsequently confirmed an intracranial space occupying lesion which was excised. Hemoglobin level normalized after tumor excision. This case report emphasizes the need for thorough systemic evaluation including central nervous system examination in children identified to be polycythemic. Keywords: CNS tumor; hemangioblastoma; polycythemia.

Secondary Polycythemia and Non-Islet Cell Tumor-induced Hypoglycemia in Advanced Hepatocellular Carcinoma: A Case Report.

Continuously holding its position as the sixth most common cause of cancer and the third leading cause of cancer death, globally, Hepatocellular Carcinoma (HCC) remains as a healthcare priority. Production of various substances may result into systemic or metabolic complications, often known as paraneoplastic phenomena of HCC. A 56-year-old male with history of untreated chronic hepatitis B arrived with generalized weakness and intermittent headache in the last two days prior to admission. Laboratory findings demonstrated elevated hemoglobin (20.5 g/dl), alpha-fetoprotein (29,845 ng/dl), and d-Dimer (2,120 ng/ml) levels. Hypoglycemia (44 mg/dl) was documented with normal basal insulin level, confirming non-islet cell tumor hypoglycemia. Abdominal multiphasic CT-scan demonstrated a large solid lesion involving the whole right liver lobe, hyper-enhanced at arterial phase and wash-out pattern at venous and delayed phases, with portal vein thrombosis; thus, confirming HCC BCLC C. Further examinations revealed hypercellularity from bone marrow biopsy with the absence of JAK2 mutation. He underwent serial phlebotomy and received 80 mg acetylsalicylic acid orally, as well as cytoreductive agent to reduce the risk of thrombosis. Despite applications of different interventions, control of hypoglycemia could not be achieved without parenteral administration of high dextrose load. He was planned to receive oral multikinase inhibitor, however, he passed away due to severe hospital-acquired pneumonia. Paraneoplastic phenomena are common in HCC. Increased risk of blood hyper-viscosity and thrombosis attributed to polycythemia, as well as medical emergency resulting from hypoglycemia showed that both conditions should not be overlooked since they may worsen the patient's prognosis.

JAKCalc: A machine-learning approach to rationalized JAK2 testing in patients with elevated hemoglobin levels.

The demand for Janus Kinase-2 (JAK2) testing has been disproportionate to the low yield of positive results, which highlights the need for more discerning test strategies. The aim of this study is to introduce an artificial intelligence application as a more rational approach for testing JAK2 mutations in cases of erythrocytosis. Test results were sourced from samples sent to a tertiary hospital's genetic laboratory between 2017 and 2023, meeting 2016 World Health Organization criteria for JAK2V617F mutation testing. The JAK2 Somatic Mutation Screening Kit was used for genetic testing. Machine learning models were trained and tested using Python programming language. Out of 458 cases, JAK2V617F mutation was identified in 13.3%. There were significant differences in complete blood count parameters between mutation carriers and non-carriers. Various models were trained with data, with the random forest (RF) model demonstrating superior precision, recall, F1-score, accuracy, and area under the receiver operating characteristic, all reaching 100%. Gradient boosting (GB) model also showed high scores. When compared with existing algorithms, the RF and GB models displayed superior performance. The RF and GB models outperformed other methods in accurately identifying and classifying erythrocytosis cases, offering potential reductions in unnecessary testing and costs.

Updated threshold, renewed problems: should the diagnostic criteria of polycythemia vera be reconsidered? A retrospective cross-sectional cohort study.

OBJECTIVE: This aim of this study was to evaluate hemoglobin and hematocrit values of polycythemia vera and secondary polycythemia patients with updated World Health Organization thresholds. In addition, by determining our own threshold values, we aimed to demonstrate the necessity of bone marrow biopsy and genetic analysis to be used for further diagnosis in patients with high-normal hematocrit and hemoglobin values. METHODS: A cross-sectional and retrospective study was performed with the medical records of patients from Eskisehir City Hospital hematology clinics and outpatient clinics between July 1, 2019 and July 1, 2020. The study included patients with polycythemia, divided into two groups according to polycythemia vera and secondary polycythemia. A bone marrow biopsy was performed on patients with either Janus kinase mutation positivity and/or subnormal erythropoietin levels. Receiver operating characteristics analysis was used to find threshold values, and the diagnostic efficiency of these values in differentiating World Health Organization thresholds in 2008 and 2016 was evaluated. RESULTS: A total of 73 patients were included. The median age was 43.5 years (min: 18; max: 84). The hematocrit value of 54.1 was predicted to diagnose polycythemia vera with a sensitivity of 45% and a specificity of 80%. Subsequent analysis revealed that an hemoglobin value of 17.7 was indicative of diagnosing polycythemia vera with a sensitivity of 60% and a specificity of 63%. The mean follow-up length was 6.4 months (2-12). CONCLUSION: Our study demonstrated that modified World Health Organization criteria might lead to unnecessary additional tests for polycythemia vera patients with high-normal hemoglobin and hematocrit values.

Chronic obstructive pulmonary disease burden, grades and erythrocytosis at a tertiary hospital in western Uganda.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is the third leading cause of death worldwide among people over 40 years of age, and erythrocytosis is one of the major complications associated with increased mortality among COPD patients. The study aimed to determine the proportion of COPD, associated factors, and the burden of erythrocytosis among COPD participants. METHODS AND MATERIALS: A descriptive cross-sectional study design was used. A consecutive sampling technique was used to obtain study participants at the Fort Portal Regional Referral Hospital outpatient clinic. Focused history and physical examination were carried out to select eligible participants. Participants were screened using the COPD population screener for spirometry after consenting to participate. The study enrolled all adults at risk of having COPD based on the COPD population screener and able to undergo spirometry. Spirometry was carried out according to the Global Chronic Obstructive Lung Disease and European Respiratory Society guidelines, and haemoglobin concentration was measured. RESULTS: One hundred eighty participants were enrolled in the study, most of whom were females. The modal and mean age of participants was 60 years with 139 (77.2%) females and primary as the highest education level 149(82.8%). The proportion of COPD was 25% (45) [95% CI 18.9 - 32] and highest among females (68.9%) and those aged 60 years and above (70%). The combined COPD assessment tool groups had a proportion of 55.6%, 37.8%, 4.4%, and 2.2% for groups A, B, C, and D, respectively. Age < 50 years was protective against COPD, while for every additional year of smoking, there was an associated 6.5% increased risk compared to the general population. Additionally, the proportion of erythrocytosis among COPD participants was 6.7%. CONCLUSIONS AND RECOMMENDATIONS: There was a high proportion of COPD among study participants (25%), with a 6.7% proportion of erythrocytosis. We recommend a complete blood count for every patient in groups C and D of the ABCD COPD GOLD groups.

Significant thrombus in saccular aneurysm in a patient with polycythemia: a case report.

BACKGROUND: Morphologically, the risk of aortic aneurysm rupture is mainly evaluated based on its type (e.g., fusiform or saccular) and diameter. Based on the finite element analysis, peak wall stress has been identified as a more sensitive and specific predictor of rupture in recent years. Moreover, in finite analysis, the neck of aneurysm is the highest peak wall stress and is associated with the rupture point. CASE PRESENTATION: A saccular aortic aneurysm (84 mm) was incidentally detected during preoperative examination for chronic empyema in a 74-year-old male patient with a history of polycythemia. Aortic arch graft replacement using an open stent was performed. CONCLUSIONS: Morphologically, this case was associated with a very high risk of rupture; nevertheless, it did not rupture. In this case, a mural thrombus (likely formed due to polycythemia) covered the neck of aneurysm that is experiencing the highest peak wall stress and is associated with the rupture point. The mural thrombus decreased peak wall stress and could reduce the risk of rupture even for huge saccular aneurysms. Furthermore, the mural thrombus was fully occupied in aneurysms, such as during coil embolization. Thus, polycythemia could decrease the risk of rupture of huge saccular aneurysms.

Myomatous erythrocytosis syndrome: a uterine fibroid associated with polycythaemia.

Myomatous erythrocytosis syndrome (MES) is a rare form of secondary erythrocytosis seen with myomas. Here, we present a case of a postmenopausal, nulliparous woman in her 50s incidentally found to have asymptomatic erythrocytosis on routine laboratory work. She was found to have an 18.5 cm myoma and after surgical resection, the patient's haematological values returned to normal ranges after a few weeks. This established the diagnosis as MES. The aetiology of MES continues to remain unknown but is most likely caused by an autonomous production of erythropoietin from the myomatous tissue. This case highlights obtaining a detailed history and physical examination to differentiate between the different causes of erythrocytosis, considering MES as a rare cause of secondary erythrocytosis and to prevent unnecessary procedures such as phlebotomy as surgery is the mainstay of treatment.

Secuencia anemia-policitemia en la gestación monocorial. Manejo prenatal y resultados perinatales / Twin anaemia polycythemia polycythemia sequence in monochorionic gestation. Prenatal management and perinatal outcomes

Introducción: El objetivo de este trabajo consiste en describir y analizar los resultados perinatales de una serie de casos de anemia-policitemia (TAPS) seguidos y tratados en un centro de referencia en Medicina Fetal, en términos del tipo TAPS y la conducta prenatal aplicada. Métodos: Análisis estadístico descriptivo e inferencial con el programa IBM SPSS Statistics. Resultados: Se diagnosticaron 13 casos de TAPS en un total de 510 gestaciones monocoriales. La mayoría de TAPS espontáneos se diagnosticaron en estadios precoces (5 casos), mientras que, en TAPS posláser, 3/6 casos se diagnosticaron en estadios avanzados. Cuatro fetos (4/26; 15,4%) presentaron alteraciones en la neurosonografía, 3 (3/14; 21,4%) en TAPS espontáneos y uno (1/12, 8,3%) en TAPS posláser (p = 0,308). Se detectó hipertrofia miocárdica en 7 fetos, 5 (71,4%) de los cuales correspondían a TAPS en estadios avanzados. Cuatro eran TAPS espontáneos (4/14; 28,6%) y 3 TAPS posláser (3/12; 25%) (p = 0,797). Ocho casos (8/13; 62,5%) precisaron algún procedimiento de terapia fetal. Se produjeron 3 muertes fetales anteparto y una pareja decidió interrupción legal del embarazo (19,23%). Las 5 pérdidas se produjeron en estadio IV (p=0,008).La supervivencia global fue del 80,8% (21/26 recién nacidos vivos). No hubo diferencias significativas en función del tipo TAPS (p = 0,159) y la conducta prenatal adoptada (p = 0,746). Conclusiones: El TAPS espontáneo es, por tanto, una entidad clínica con un impacto en los resultados perinatales similar al posláser. Parece que la conducta expectante y el láser consiguen mayor edad gestacional al nacimiento.(AU)

Introduction: The aim of this paper is to describe and analyze the perinatal outcomes of a series of TAPS cases followed and treated in a Fetal Medicine referral center, in terms of the type of TAPS and the prenatal behavior applied. Methods: Descriptive and inferential statistical analysis with IBM SPSS Statistics software. Results: Thirteen cases of TAPS were diagnosed in a total of 510 monocorial gestations. Most of the spontaneous TAPS were diagnosed at early stages (5 cases), whereas, in post-laser TAPS, 3/6 cases were diagnosed at advanced stages. Four fetuses (4/26; 15.4%) presented alterations in neurosonography, 3 (3/14; 21.4%) in spontaneous TAPS and one (1/12, 8.3%) in post-laser TAPS (P=0.308). Myocardial hypertrophy was detected in 7 fetuses, 5 (71.4%) of which corresponded to advanced stage TAPS. Four were spontaneous TAPS (4/14; 28.6%) and 3 were post-laser TAPS (3/12; 25%) (P=0.797). Eight cases (8/13; 62.5%) required some fetal therapy procedure. There were 3 antepartum fetal deaths and one couple decided to legally terminate the pregnancy (19.23%). All 5 losses were stage IV (P=0.008). Overall survival was 80.8% (21/26 live newborns). There were no significant differences according to the type of TAPS (P= 0.159) and the prenatal behavior adopted (P=0.746).Conclusions: Spontaneous TAPS is therefore a clinical entity with an impact on perinatal outcomes similar to post-laser. It seems that expectant management and laser achieve higher gestational age at birth.(AU)

Peculiar CADASIL phenotype in monozygotic twins carrying a novel NOTCH3 pathogenetic variant.

BACKGROUND: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominantly inherited cerebral small vessel disease caused by Neurogenic locus notch homolog protein 3 (NOTCH3) gene mutations. The main clinical features include migraine with aura, recurrent ischemic strokes and dementia. Brain MRI typically shows multiple small lacunar infarcts and severe, diffuse, symmetrical white matter hyperintensities (WMHs), with characteristic involvement of the anterior temporal pole, external capsule, and superior frontal gyrus. Reports of twins with CADASIL are scarce. Herein we describe a pair of monozygotic twins with peculiar CADASIL phenotype, carrying a new NOTCH3 variant. CASE PRESENTATION: Twin A was a 45-year-old male suffering from migraine, obesity, arterial hypertension, and polycythemia (with negative genetic analysis), who complained of a transient, short-lasting (~ 5 minutes) episode of speech difficulties. Brain MRI showed diffuse, symmetrical, confluent periventricular WMHs involving frontal, parietal, and temporal lobes and external capsules, with sparing of anterior temporal poles. Genetic analysis of NOTCH3 gene demonstrated the presence of missense c.3329G>A, p.(Cys1110Tyr) variant, confirming CADASIL diagnosis. Twin B, affected by migraine and polycythemia, as well as his monozygotic twin, presented with a 2-month history of trigeminal neuralgia. Brain MRI demonstrated diffuse WMHs with a pattern of distribution like his twin. Genetic analysis revealed the same NOTCH3 pathogenic variant. CONCLUSIONS: Our monozygotic twins have a strikingly similar neuroimaging picture with sparing of anterior temporal poles. They also have a peculiar phenotype, both presenting polycythemia without genetically confirmed cause. Twin B had trigeminal neuralgia, that is unusual in CADASIL. The possible association of the peculiar findings with the newly reported NOTCH3 variant needs to be confirmed with further observations.

Zebrafish mutants in egln1 display a hypoxic response and develop polycythemia.

AIMS: Prolyl hydroxylase domain 2 (PHD2), encoded by the Egln1 gene, serves as a pivotal regulator of the hypoxia-inducible factor (HIF) pathway and acts as a cellular oxygen sensor. Somatic inactivation of Phd2 in mice results in polycythemia and congestive heart failure. However, due to the embryonic lethality of Phd2 deficiency, its role in development remains elusive. Here, we investigated the function of two egln1 paralogous genes, egln1a and egln1b, in zebrafish. MAIN METHODS: The egln1 null zebrafish were generated using the CRISPR/Cas9 system. Quantitative real-time PCR assays and Western blot analysis were employed to detect the effect of egln1 deficiency on the hypoxia signaling pathway. The hypoxia response of egln1 mutant zebrafish were assessed by analyzing heart rate, gill agitation frequency, and blood flow velocity. Subsequently, o-dianisidine staining and in situ hybridization were used to investigate the role of egln1 in zebrafish hematopoietic function. KEY FINDINGS: Our data show that the loss of egln1a or egln1b individually has no visible effects on growth rate. However, the egln1a; egln1b double mutant displayed significant growth retardation and elevated mortality at around 2.5 months old. Both egln1a-null and egln1b-null zebrafish embryo exhibited enhanced tolerance to hypoxia, systemic hypoxic response that include hif pathway activation, increased cardiac activity, and polycythemia. SIGNIFICANCE: Our research introduces zebrafish egln1 mutants as the first congenital embryonic viable systemic vertebrate animal model for PHD2, providing novel insights into hypoxic signaling and the progression of PHD2- associated disease.

Suspected renal interstitial cell tumor causing polycythemia in two dogs.

Here we report a case series of two dogs diagnosed as renal interstitial cell tumor (RICT) accompanied by elevated serum erythropoietin level and marked polycythemia. RICT is a rare tumor in dogs, originating from renal interstitial cells. While several renal tumors such as renal lymphoma, adenocarcinoma, carcinoma, sarcoma, fibrosarcoma and nephroblastoma may cause polycythemia, polycythemia caused by RICT has never been reported in dogs. The tumors in both dogs were solitary and lied within cortex or cortico-medullary junction. Histopathology revealed spindle-shaped cells suggesting mesenchymal origin, with no mitotic figures suggesting that the tumors in both dogs were benign. Following surgical removal of the affected kidney, serum erythropoietin level and polycythemia normalized in both dogs.

Rusfertide, a Hepcidin Mimetic, for Control of Erythrocytosis in Polycythemia Vera.

BACKGROUND: Polycythemia vera is a chronic myeloproliferative neoplasm characterized by erythrocytosis. Rusfertide, an injectable peptide mimetic of the master iron regulatory hormone hepcidin, restricts the availability of iron for erythropoiesis. The safety and efficacy of rusfertide in patients with phlebotomy-dependent polycythemia vera are unknown. METHODS: In part 1 of the international, phase 2 REVIVE trial, we enrolled patients in a 28-week dose-finding assessment of rusfertide. Part 2 was a double-blind, randomized withdrawal period in which we assigned patients, in a 1:1 ratio, to receive rusfertide or placebo for 12 weeks. The primary efficacy end point was a response, defined by hematocrit control, absence of phlebotomy, and completion of the trial regimen during part 2. Patient-reported outcomes were assessed by means of the modified Myeloproliferative Neoplasm Symptom Assessment Form (MPN-SAF) patient diary (scores range from 0 to 10, with higher scores indicating greater severity of symptoms). RESULTS: Seventy patients were enrolled in part 1 of the trial, and 59 were assigned to receive rusfertide (30 patients) or placebo (29 patients) in part 2. The estimated mean (±SD) number of phlebotomies per year was 8.7±2.9 during the 28 weeks before the first dose of rusfertide and 0.6±1.0 during part 1 (estimated difference, 8.1 phlebotomies per year). The mean maximum hematocrit was 44.5±2.2% during part 1 as compared with 50.0±5.8% during the 28 weeks before the first dose of rusfertide. During part 2, a response was observed in 60% of the patients who received rusfertide as compared with 17% of those who received placebo (P = 0.002). Between baseline and the end of part 1, rusfertide treatment was associated with a decrease in individual symptom scores on the MPN-SAF in patients with moderate or severe symptoms at baseline. During parts 1 and 2, grade 3 adverse events occurred in 13% of the patients, and none of the patients had a grade 4 or 5 event. Injection-site reactions of grade 1 or 2 in severity were common. CONCLUSIONS: In patients with polycythemia vera, rusfertide treatment was associated with a mean hematocrit of less than 45% during the 28-week dose-finding period, and the percentage of patients with a response during the 12-week randomized withdrawal period was greater with rusfertide than with placebo. (Funded by Protagonist Therapeutics; REVIVE ClinicalTrials.gov number, NCT04057040.).

Deficiency in PHD2-mediated hydroxylation of HIF2α underlies Pacak-Zhuang syndrome.

Pacak-Zhuang syndrome is caused by mutations in the EPAS1 gene, which encodes for one of the three hypoxia-inducible factor alpha (HIFα) paralogs HIF2α and is associated with defined but varied phenotypic presentations including neuroendocrine tumors and polycythemia. However, the mechanisms underlying the complex genotype-phenotype correlations remain incompletely understood. Here, we devised a quantitative method for determining the dissociation constant (Kd) of the HIF2α peptides containing disease-associated mutations and the catalytic domain of prolyl-hydroxylase (PHD2) using microscale thermophoresis (MST) and showed that neuroendocrine-associated Class 1 HIF2α mutants have distinctly higher Kd than the exclusively polycythemia-associated Class 2 HIF2α mutants. Based on the co-crystal structure of PHD2/HIF2α peptide complex at 1.8 Å resolution, we showed that the Class 1 mutated residues are localized to the critical interface between HIF2α and PHD2, adjacent to the PHD2 active catalytic site, while Class 2 mutated residues are localized to the more flexible region of HIF2α that makes less contact with PHD2. Concordantly, Class 1 mutations were found to significantly increase HIF2α-mediated transcriptional activation in cellulo compared to Class 2 counterparts. These results reveal a structural mechanism in which the strength of the interaction between HIF2α and PHD2 is at the root of the general genotype-phenotype correlations observed in Pacak-Zhuang syndrome.

[How I manage polycythemia]. / Comment j'explore une polyglobulie.

Polycythemia is suspected when hemoglobin and/or hematocrit levels exceed established norms based on gender and age. This biological anomaly can arise from a myeloproliferative neoplasm known as polycythemia vera, or be secondary to excess erythropoietin (EPO) or decreased in plasma volume. Faced with polycythemia, the search for JAK2 mutations and measurement of serum EPO levels can guide toward the etiology. In polycythemia vera, thromboembolic events are the most lethal complications and unfortunately often the initial manifestation of the disease. The condition can also progress to myelofibrosis or acute leukemia. Management aims at reducing the hematocrit below 45 %, in order to limit, but not completely prevent, thrombo-embolic complications. This article elaborates on the clinical considerations around this biological anomaly, relevant complementary examinations, and briefly the therapeutic management.

La polyglobulie est suspectée lorsque le taux d'hémoglobine et/ou d'hématocrite est au-dessus des normes définies selon le sexe et l'âge. Cette anomalie biologique peut survenir à la suite d'une néoplasie myéloproliférative appelée polycythemia vera (PV), être secondaire à un excès d'érythropoïétine (EPO) ou à une diminution du volume plasmatique. Face à une polyglobulie, la recherche de mutations du gène JAK2 et un dosage d'EPO sérique permettront d'orienter vers l'étiologie. En cas de PV, les phénomènes thrombo-emboliques sont les complications les plus léthales et sont malheureusement souvent la première manifestation de la maladie. La maladie peut également évoluer en myélofibrose ou en leucémie aiguë. La prise en charge vise à réduire le taux d'hématocrite en-dessous de 45 %, afin de limiter, sans les empêcher complètement, les complications thrombo-emboliques. Dans cet article, nous développons la réflexion clinique autour de cette anomalie biologique, les examens complémentaires pertinents dans ce domaine et, brièvement, la prise en charge thérapeutique.

Neonatal polycythemia: prevalence, risk factors and predictors of severity.

BACKGROUND: Polycythemia is a disorder with several causes and risk factors. The clinical presentation is variable, ranging from asymptomatic newborns to cases with severe physiological changes. The aim of this study was to assess the prevalence, risk factors and predictors of severity of polycythemia in a Portuguese level III Neonatal Intensive Care Unit (NICU). METHODS: Case-control study of all term newborns with the diagnosis of polycythemia admitted to the NICU of the São João Universitary Hospital Center, Porto, Portugal, from January 1, 1999 to December 31, 2019; and who met one of the following inclusion criteria were eligible for the study: 1) Hct>65% or Hb>22 g/dL; and 2) Hb≥21 g/dL with clinical manifestations of polycythemia. RESULTS: A total of 53 newborns fulfilled the inclusion criteria and were included in the study, corresponding to a prevalence of 0.57%. Birth outside the hospital was the only risk factor with statistical significance. Of 53 cases, 51 (96.23%) had symptomatic polycythemia. The most frequent symptoms were: hyperbilirubinemia (69.81%), hypoglycemia (52.83%), thrombocytopenia (50.94%), cardiorespiratory (33.96%), and neurological symptoms (33.96%). Of the 53 newborns evaluated, 41 (77.36%) needed treatment. The only risk factors that influenced the hematocrit value were maternal diabetes and fetal growth restriction. CONCLUSIONS: The best way to improve the prognosis of polycythemia is to identify the risk factors present throughout pregnancy and make an early diagnosis and treatment. Out-of-hospital births should be avoided. The diagnosis should not be excluded, even if hemoglobin and hematocrit are within normal limits.

Falsely prolonged prothrombin time test in a patient with erythrocytosis: a case report.

The prothrombin time (PT) test is commonly used to monitor deficiencies in coagulation factors. A prolonged PT may indicate a deficiency of factors II, V, VII, X, and fibrinogen, or the presence of an inhibitor. However, further tests are required to differentiate between a true factor deficiency and the presence of an inhibitor. It is important to note that falsely prolonged PT can lead to misdiagnosis and inappropriate clinical intervention that can have life-threatening consequences. A 19-year-old woman with elevated hematocrit levels and prolonged PT was diagnosed with secondary erythrocytosis due to cyanotic congenital heart disease with ventricular septal defect (VSD). However, further investigation revealed that the prolonged PT result was false. Excess citrate in the blood sample, caused by polycythemia, led to this misleading outcome, resulting in unnecessary and potentially harmful treatment. This incident emphasizes the importance of laboratory personnel and clinicians being aware of the test's limitations. Not only should specialists in thrombosis and hemostasis possess this knowledge, but it is also pertinent for general laboratory staff, as well as laboratory directors and specialists. The significance of accurate laboratory testing for the proper diagnosis and treatment of patients is highlighted in this case.

Idiopathic erythrocytosis: A diagnostic and management challenge with emerging areas for exploration.

Despite published algorithms for approaching the work-up of erythrocytosis, a significant proportion of patients are left with uncertainty as to its aetiology and prognosis. The term 'idiopathic erythrocytosis' (IE) is applied when known primary and secondary aetiologies have been ruled out. However, the assignment of secondary aetiologies is not always straightforward or evidence based, which can lead to misdiagnosis and heterogeneity in cohort studies. Furthermore, new studies have identified germline or somatic mutations that may affect prognosis. Epidemiological and cohort data are inconsistent as to whether IE increases the risk for complications such as arterial and venous thromboembolism, clonal transformation or comorbid conditions. Randomized trials assessing the role of phlebotomy for long-term management of IE have not been performed, so treatment remains a vexing problem for clinicians. Standardization of terminology and testing strategies, including comprehensive genetic screening in clinical research, are key to refining our understanding of IE.

Effects of timing of cord clamping on neonatal hemoglobin and bilirubin levels in preterm and term infants-A prospective observational cohort study.

BACKGROUND: Delayed cord clamping (DCC) is a proven beneficial intervention, but the suggested timings of DCC vary from 30 to 300 seconds after birth or until cord pulsation stops. This study aimed to find the optimum timing of DCC to maximize the benefits such as an increase in hemoglobin, and hematocrit without increasing the risks of polycythemia and hyperbilirubinemia. METHODS: We conducted a single-center prospective observational cohort study. All singleton neonates with gestational age ≥ 28 weeks born at the center in the 17 months of the study period from November 2020 to March 2022 were enrolled. Participants were divided into four groups based on DCC time: group A: <60 sec, group B: 60-119 sec, group C: 120-180 sec, and group D: >180 sec. The primary outcome was the levels of hemoglobin, hematocrit, and bilirubin at 48 hours of life. RESULTS: Four hundred and eight neonates were enrolled. They were divided into four groups based on the timing of DCC (group A: n = 52, group B: n = 137, group C: n = 155, group D: n = 64). With an increase in the duration of DCC, there was an increase in the level of hemoglobin and hematocrit without an increase in the risk of polycythemia or neonatal hyperbilirubinemia. The benefits were best in group C (120-180 sec) and group D (>180 sec). CONCLUSIONS: DCC of ≥ 120 seconds appears to be optimal where hemoglobin and hematocrit are highest without an increase in the risk of neonatal hyperbilirubinemia. The risk of adverse effects like polycythemia or neonatal hyperbilirubinemia requiring phototherapy did not increase even after extending the time of cord clamping to >180 seconds.

Idiopathic erythrocytosis: a germline disease?

Polycythemia Vera (PV) is typically caused by V617F or exon 12 JAK2 mutations. Little is known about Polycythemia cases where no JAK2 variants can be detected, and no other causes identified. This condition is defined as idiopathic erythrocytosis (IE). We evaluated clinical-laboratory parameters of a cohort of 56 IE patients and we determined their molecular profile at diagnosis with paired blood/buccal-DNA exome-sequencing coupled with a high-depth targeted OncoPanel to identify a possible underling germline or somatic cause. We demonstrated that most of our cohort (40/56: 71.4%) showed no evidence of clonal hematopoiesis, suggesting that IE is, in large part, a germline disorder. We identified 20 low mutation burden somatic variants (Variant allelic fraction, VAF, < 10%) in only 14 (25%) patients, principally involving DNMT3A and TET2. Only 2 patients presented high mutation burden somatic variants, involving DNMT3A, TET2, ASXL1 and WT1. We identified recurrent germline variants in 42 (75%) patients occurring mainly in JAK/STAT, Hypoxia and Iron metabolism pathways, among them: JAK3-V722I and HIF1A-P582S; a high fraction of patients (48.2%) resulted also mutated in homeostatic iron regulatory gene HFE-H63D or C282Y. By generating cellular models, we showed that JAK3-V722I causes activation of the JAK-STAT5 axis and upregulation of EPAS1/HIF2A, while HIF1A-P582S causes suppression of hepcidin mRNA synthesis, suggesting a major role for these variants in the onset of IE.