Normal Erythropoietin Levels Research Articles

The Gaisbock syndrome after COVID-19 pneumonia

In 1905, Felix Gaisbock, MD, described a syndrome in patients with hypertension, elevated hematocrit levels, plethoric appearances, and no splenomegaly. He postulated this relative erythrocytosis was due to stress. In this case report, a 40-year-old Caucasian man with obesity was admitted with recurrent deep vein thrombosis and increasing oxygen requirements 2 weeks after hospitalization with COVID-19 pneumonia. This patient had a 10-year history of untreated hypertension and erythrocytosis. He had a ruddy appearance, a normal erythropoietin level, and a negative JAK2 V617 mutation. In this case, Gaisbock syndrome was suspected.

Congenital Methemoglobinemia Under Diagnosed Condition with Variiable Therapeurtic Options

Methemoglobinemia is a rare overlooked differential diagnosis in patients with cyanosis and dyspnea unrelated to cardiopulmonary causes.Methemoglobin results from oxidation of ferrous iron to ferric iron within the heme moiety of hemoglobin . In healthy individuals, less than 1% of hemoglobin is present in the oxidized form (methemoglobin), which has limited ability to carry oxygen, however with increased oxygen affinity at the remaining binding sites .This results in decrease of oxygen delivery to tissue leading to hypoxaemia and lactic acidosis.Methemoglobin reductase enzyme deficiency is either type I or type II; type I: Cytochrome b5 reductase deficiency, demonstrable only in the erythrocytes, presents as uncomplicated, benign methemoglobinemia, and associated with a normal life expectancy with only fatigue and dyspnea being the most commonly reported symptoms.Hereditary type II methemoglobinemia, is global (affects both red and white blood cells) and is associated with severe neurologic dysfunction and reduced life expectancy . The enzyme's activity is less than 20% of normal.Type II congenital methemoglobinemia constitutes approximately 10% of all cases of congenital methemoglobinemia and usually causes death within the first few years of lifeThere is a significant delay in the onset of symptoms in a patient with type I hereditary methemoglobinemia, as most studies indicate that patients are asymptomatic in infancy and childhood.we report a 29 year old Indian non-smoker male, his story started 6 months prior to presentation when he had generalized fatigue and discoloration of hands. He presented with persistent polycythaemia with elevated hemoglobin level. The patient was misdiagnosed in another center as polycythaemia and treated with Imatinib. The diagnosis of PV was revisited and ruled out in view of negative JAK2, normal erythropoietin level and absence of features of panmyelosis.Clinical cyanosis and low oxygen saturation in the presence of normal arterial oxygen tension was highly suggestive of methemoglobinemia.Arterial blood gas (ABG) revealed a methemoglobin level of 38% (normal: 0-1.5%). Cytochrome B5 reductase (Methemoglobin reductase B) wasdeficient at level of <2.6 U/g Hb) (normal: 6.6-13.3), consistent with methemoglobin reductase (cytochrome b5) deficiency and hence the diagnosis of congenital methemoglobinemia was established.The role of Imatinib in provoking methemoglobinemia is questionable and association between Imatinib and methemoglobinemia never described before. There was no history of other drugs offended in aggravating the patients' symptoms and cyanosis.The patient started on Vitamin C 500 mg for which he responded well with less cyanosis and significant reduction of methemoglobin level.Upon extensive review of English literature for cases of congenital Methaemoglobinaemia due to deficiency of cytochrome b5 reductase, we found 23 cases diagnosed as type I (including the case reported here).17 cases (~74%) of type I and 6 cases (27%) of type II. There is male predominance (73%) versus 26% in females. Almost half of reported cases (12 cases; 52%) are indian, 2 Japanese, 3 English, 2 Arabic, one Spanish and one Italian.For type I, the median calculated age is 31 years with cyanosis and shortness of breath being the most common sign and symptom.For type II: Six cases were reported, all in pediatric age group with median calculated age at presentation is 6 years with neurologic manifestations and mental retardation are the most common type II associated symptoms.Congenital methemogobinemia is a rare underreported hemoglobin disease. Due to lack of systematic epidemiological studies it is usually under investigated and frequently clinically missed especially when presenting in adulthood. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

JAK2 Negative Erythrocytosis Associated with JAK2 GGCC_46/1 Haplotype, Calr rs1049481_G, and Normal Erythropoietin Level: Is This a New Entity?

Introduction. The JAK2 haplotype known as "GGCC or 46/1 haplotype" consists of a germline combination of single nucleotide polymorphisms (SNPs) that are inherited together and are frequently associated with the onset of myeloproliferative neoplasms (MPNs) positive for both JAK2 V617 and exon 12 mutations. It has been reported a significant association between JAK2 negative erythrocytosis and the simultaneous occurrence of JAK2 haplotype GGCC_46/1 and CALR rs1049481_G allele, mapping in the 3' UTR of the gene. In the present study, we investigated the presence of JAK2 haplotype GGCC_46/1 and CALR rs1049481_G allele in a more extensive series of erythrocytosis patients and evaluated a possible correlation with serum erythropoietin (EPO) level. Methods. Fifty-nine erythrocytosis patients, diagnosed at our Center from 2009 to 2020, negative for canonical JAK2 mutations, and secondary causes, were included in this study. Forty-nine (83%) out of 59 cases met only two major WHO 2016 diagnostic criteria for polycythemia vera (PV); the remaining 10 cases were "JAK2 negative PV", as they also showed the minor criterion with subnormal serum EPO. Genomic DNA from all patients was extracted from peripheral blood granulocytes and analyzed for the presence of both SNPs. The occurrence of the JAK2 haplotype was investigated by analyzing rs10974944 tagging SNP, using distal JAK2 intron 12 primers (forward: 5'-CTGTGCAGTCCAAACCCATG-3' and reverse: 5'-TTCTCTGCTTGCTAGTGGGT-3'). This amplification generated a PCR product of 272 bp, revealing a C/G substitution by Sanger sequencing. PCR investigated the occurrence of the G/T allele in the SNP rs1049481 in the CALR gene with primers CALR-UTR-F 5'-GACAAGGAGGATGATGAGGACAAA-3' and CALR-UTR-R 5'- AAAAATGAAAGTTCTCGAGTCTCACAGA-3' generating a 205 bp product. In silico data from 2504 healthy individuals of the 1000G Project (1000G) were used as a control group. Fisher's exact test was used to compare the differences of both SNPs and the frequency of their alleles between cases and controls, respectively; the c-square test was employed for evaluating the distribution of JAK2 GGCC haplotype in erythrocytosis patients and controls. Results. Thirty-eight (64.4%) and 21 (35.6%) cases resulted in being positive and negative for the JAK2 GGCC haplotype, respectively. The JAK2 GGCC haplotype occurred to be associated with erythrocytosis as a statistically significant difference in frequency was detected as respect to 2504 healthy individuals from the 1000G Project (p=0.0013). This finding was also confirmed considering the Genome Aggregation Database (gnomAD v2.1.1, https://gnomad.broadinstitute.org/)(p=0.0024). The association was also demonstrated in terms of allelic frequency (p=0.0131) and genotype distribution (p=0.0030). Regarding CALR rs1049481 SNP, a significant difference in the CALR rs1049481_G allelic rate was confirmed in our cohort compared to 1000G controls (p=0.0360). Overall, the association between JAK2 GGCC haplotype and CALR rs1049481_G was observed in 28/59 (47.5%) erythrocytosis cases compared to healthy individuals (628/2504, 25%), and this difference resulted in being statistically significant (p=0.0002). Based on the EPO level, erythrocytosis patients were divided into two groups: normal (49 cases) or subnormal (10 cases). Interestingly, the simultaneous presence of JAK2 GGCC haplotype and CALR rs1049481_G was statistically significantly associated with the erythrocytosis group showing normal EPO (p=0.0133). Conclusions. This study suggests that the JAK2 GGCC haplotype and the presence of the CALR rs1049481_G allele were significantly associated with erythrocytosis cases, negative for canonical JAK2 mutations. Our findings are in line with recent literature evidence showing that germline predisposition factors such as SNPs and haplotypes may play a crucial role in MPN pathogenesis. Moreover, this study shows that patients showing two major WHO 2016 diagnostic criteria (erythrocytosis and panmyelosis) without JAK2 mutations and with normal EPO levels can benefit from the search for germline polymorphisms combination in JAK2 and CALR driver genes for a better diagnostic classification. Therefore, the presence of these polymorphisms could represent a novel minor criterion for the diagnosis of "JAK2 negative PV". Disclosures No relevant conflicts of interest to declare.

Erythrocytosis following allogeneic hematopoietic stem cell transplantation

Post-transplant erythrocytosis (PTE) following allogeneic hematopoietic stem cell transplantation (alloHSCT) is rare, and the clinical characteristics of this condition remain unknown. In this study, we examined the clinical characteristics of three PTE cases among 321 patients who received allo HSCT from January 1992 to December 2011 at our institution. All three patients exhibited normal levels of white blood cell and platelet counts when their hemoglobin levels reached their peak. Two patients exhibited normal levels of erythropoietin. No thrombosis or hemorrhage was observed in any of the three patients without cytoreductive therapy or an antiplatelet agent. All three patients tested negative for JAK2V617F mutations. Two patients had high levels of IL-13, an upstream signal for the JAK/STAT pathway. JAK2 is known to significantly contribute to the pathology of polycythemia vera; however, this pathology may differ from that of PTE. We believe that it is necessary to construct a more appropriate management structure for PTE by analyzing more case data in the future.

Symptomatic Hemoglobin New Mexico and a Case of Therapeutic Benefit with Acetazolamide

INTRODUCTIONInherited disorders due to rare structural Hb variants are not included in national, neonatal screening tests and therefore likely underdiagnosed. Hemoglobin New Mexico is one such rare variant with only one case ever reported in 1985 in conjunction heterozygosity for Hb S.1 This Hb variant involves a missense mutation of the β chain substituting the hydrophobic Proline β100 with the hydrophilic Arginine.1 We present here the second case of Hb New Mexico variant ever reported to our knowledge.CASE PRESENTATIONAn 18-year-old athletic, Latin American female initially presented with episodic chest pain, palpitations, fatigue, headaches, and dyspnea on exertion to the point that she could no longer exercise for one year. Work up revealed erythrocytosis persistent for >1 year with hemoglobin level of 17.3 g/dL, and hematocrit of 47.2 % (Hb went as high as 19g/dL) with normal erythropoietin level, hemoglobin electrophoresis, and JAK2 V617 with reflex to JAK3 exon 12-15 negative. She had extensive evaluation to rule out acquired causes including cardiac, pulmonary, and neurologic evaluation which was all normal. She underwent therapeutic phlebotomies with no clinical improvement over 3 months and symptoms worsened as well as new iron deficiency from phlebotomies so this was discontinued. Evaluation with p50 oxygen dissociation curve revealed high oxygen affinity. Further gene sequencing revealed heterozygous inheritance of Hb New Mexico with HbA: 54.5%, HbA2: 3.6%, and Hb New Mexico: 41.9%. Beta Globin Gene sequencing identified the following mutation: Beta 100, CCT>CGT, Pro>Arg. Her symptoms worsened as well as an episode of syncope but no new neurologic, cardiac, or pulmonary etiologies were identified and at the time Hg 18g/dL. A trial of low dose acetazolamide 125mg daily was given to the patient and her symptoms improved by a 6 week follow up with notable reduction of headache, fatigue, dyspnea, and chest pain.CONCLUSIONSGiven the rarity of this hemoglobin variant in a patient with severe symptoms, data is limited. Acetazolamide, a carbonic anhydrase inhibitor often used for migraines, is known to illicit mild acidosis and therefore potentially reduce hemoglobin-oxygen affinity and perhaps allow for relief of our patient's symptoms. Further therapeutic evaluation is warranted but likely challenging given rarity of the condition. DisclosuresNo relevant conflicts of interest to declare.

Serum Erythropoietin Levels in Essential Thrombocythemia: Phenotypic and Prognostic Correlates

Background:Subnormal serum erythropoietin (EPO) level is widely accepted as a minor diagnostic criterion for polycythemia vera (PV) and has retained its value in the revised 2016 World Health Organization (WHO) classification scheme of myeloid neoplasms (Blood. 2016;127:2391). While over 80% of PV patients exhibit subnormal EPO values (Haematologica. 2004;89:1194), very little is known about the incidence, phenotypic connotation, or prognostic significance of serum EPO levels in essential thrombocythemia (ET).Methods:Study patients were recruited from the Mayo Clinic, Rochester, MN, USA. Diagnosis of ET was in strict accordance with the 2016 WHO criteria (Blood. 2016;127:2391) and only patients with EPO measurements at diagnosis or during their chronic phase were considered under the following provisions: i) no evidence of myelofibrotic or leukemic transformation; ii) no treatment with cytoreductive agents at the time of sample collection (and for those with EPO sampling at diagnosis, no prior exposure to cytoreductive therapy); iii) no hemoglobin levels below sex-adjusted values for anemia; and iv) systematic exclusion of all cases of masked PV. Serum erythropoietin levels were measured using Mayo-verified standard immune-enzymatic assay consistent with CLIA requirements with reference range between 4-21 mIU/mL. Standard statistical methods and time-to-event curves prepared using the Kaplan-Meier method were used to compare EPO-stratified groups. The JMP® Pro 13.0.0 software package was used for all analyses (SAS Institute, Cary, NC, USA).Results:Among 177 informative ET patients (median age 51 years, range 18-88; 71% females), median serum EPO concentrations were 5.2 mIU/mL (range <1-25) overall and 2.6 mIU/mL (range <1-3.9) and 7.2 mIU/mL (range 4-25) in those with subnormal versus normal/above normal EPO levels, respectively (p<0.0001). The majority of EPO measurements were at the time or within one year of diagnosis (67%), with the remainder obtained at referral or during the chronic clinical course. Risk stratification disclosed low, intermediate, and high risk status in 45%, 33% and 23% of patients, respectively, with no appreciable differences between EPO-stratified subsets.Subnormal serum EPO levels clustered clinically with JAK2 mutations (95% vs 60%; p<0.0001), higher hemoglobin (median 14.7 vs 13.8 g/dl, range: 12.1-17.8 vs 12-17.1; p<0.0001) and leukocyte counts (median 9.7 vs 8.2 x 109/l, range: 4-28.1 vs 3.9-22; p=0.0001), and arterial thrombosis after diagnosis (13% vs 5%; p=0.04). In addition, all three documented conversions to PV (p=0.01) and none of the six fibrotic progressions (p=0.02) occurred in patients with subnormal serum EPO levels (Table 1).While serum EPO level had no bearing on overall survival data (p=0.41) (Figure 1A), subnormal circulating EPO concentrations were significantly associated with superior myelofibrosis-free survival (p=0.02) (Figure 1B) but conversely, inferior polycythemia-free survival (p=0.03) (Figure 1C).Conclusions:We conclude that subnormal serum EPO levels are relatively frequent in ET, cluster with disease features that are reminiscent of polycythemia vera, and might be associated with a lower risk of fibrotic progression. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Unmasking and aggravation of polycythemia vera by canagliflozin

Sodium-glucose co-transporter-2 inhibitors are novel antidiabetes drugs that act via inhibition of renal glucose reabsorption. This action causes osmotic diuresis, reduces intravascular volume and is associated with various adverse effects. In the present paper, we describe the first report on the unmasking of underlying polycythemia vera by canagliflozin in a person with Type 2 diabetes mellitus, which was temporally related to the use of the drug. A 51-year-old obese man with Type 2 diabetes was prescribed canagliflozin 100 mg for control of his glycaemia. He presented 6 months later with asymptomatic elevation of his haemogram measurements (haemoglobin: 16.9 g/dl; haematocrit: 55%; red cell number: 8.1 million/mm3 ; total leukocytes: 23010/mm3 ; platelet count: 9.7 *106 /mm3 ). He had no history of smoking, exposure to high altitude or other drugs. Subsequent investigations revealed myeloproliferative neoplasm (polycythemia vera) on trephine biopsy of bone marrow, normal erythropoietin level and JAK2V617F positivity. Because of the possibility that the underlying condition had been unmasked by canagliflozin, the latter was stopped. This led to a remarkable improvement in the man's haematological profile, with no other significant intervention. The man subsequently restarted the drug of his own accord, causing his haematological profile to worsen again and thereby posing a challenge in monitoring of both polycythemia vera as well as diabetes mellitus. This report brings to light unmasking of a new adverse effect of sodium-glucose co-transporter-2 inhibitors in clinical practice caused by volume loss, apart from hypotension and falls.

Congenital methemoglobinemia misdiagnosed as polycythemia vera: Case report and review of literature.

Methemoglobinemia is a rare overlooked differential diagnosis in patients presented with cyanosis and dyspnea unrelated to cardiopulmonary causes. Our patient is 29 year old Indian non-smoker male, his story started 6 months prior to presentation to our center when he had generalized fatigue and discoloration of hands. He presented with persistent polycythemia with elevated hemoglobin level. The patient was misdiagnosed in another center as polycythemia and treated with Imatinib. The diagnosis of PV was revisited and ruled out in view of negative JAK2, normal erythropoietin level and absence of features of panmyelosis. Clinical cyanosis and lowoxygen saturation in the presence of normal arterial oxygen tension was highly suggestive of methemoglobinemia. Arterial blood gas revealed a methemoglobin level of 38% (normal: 0-1.5%). Cytochrome B5 reductase (Methemoglobin reductase B) was deficient at level of <2.6 U/g Hb) (normal: 6.6-13.3), consistent with methemoglobin reductase (cytochrome b5) deficiency and hence the diagnosis of congenital methemoglobinemia was established. The role of Imatinib in provoking methemoglobinemia is questionable and association between Imatinib and methemoglobinemia never described before. In our case, there were no other offending drugs in aggravating the patients’ symptoms and cyanosis. The patient started on Vitamin C 500 mg once daily for which he responded well with less cyanosis and significant reduction of methemoglobin level. Congenital methemoglobinemia is a rare underreported hemoglobin disease and often clinically missed. Upon extensive review of English literature for cases of congenital methemoglobinemia due to deficiency of cytochrome b5 reductase, we found 23 cases diagnosed as type I (including the case reported here). 17 cases (~74%) of type I and 6 cases (27%) of type II. There is male predominance 73% versus 26% in females. Almost half of reported cases 12 cases (52%) are Indian, 2 Japanese, 3 English, 2 Arabic, one case Spanish and one case Italian. For type I, the median calculated age is 31 years with cyanosis and shortness of breath being the most common sign and symptoms. For type II: Six cases were reported in English literature, all in pediatric age group with median calculated age at presentation is 6 years with neurologic manifestations and mental retardation are the most common type II associated symptoms. Due to lack of systematic epidemiological studies, congenital methemoglobinemia is under diagnosed as it is under investigated and usually overlooked especially when presenting in adulthood and in absence of obvious acquired agents.

Endogenic erythropoietin secretion in patients undergoing off-pump coronary artery bypass grafting.

Erythropoietin (EPO) deficiency or inadequate EPO secretion in response to bleeding may result in profound or prolonged anaemia after cardiac surgery. The aim of the study was to evaluate the changes in EPO secretion in patients undergoing off-pump coronary artery bypass grafting (OPCAB). Blood samples from 43 patients (mean age 65.1 ± 7.6 years) were obtained before surgery and on the 1st, 2nd, and 6th day post isolated OPCAB. EPO levels ≥ 4.3 mIU/mL were considered normal. Thirteen (30%) patients had the preoperative EPO level below normal range even though their preoperative haemoglobin was ≥ 13 g/dL. In patients with basal EPO deficiency lower peak EPO levels were observed compared to the group with normal basal EPO levels, even though reduction in haemoglobin concentrations was comparable in both groups. Moreover, lower reticulocytosis was noted on day 1 (8.5 ± 4.0‰ vs. 11.7 ± 4.4‰; p = 0.04) and a tendency toward lower values was seen on day 2 (9.6 ± 4.3‰ vs. 13.0 ± 5.8‰; p = 0.07) among patients with preoperative EPO deficiency. Erythropoietin deficiency is common in patients scheduled for OPCAB, and it results in diminished increase in EPO secretion in response to bleeding. Consequently, in patients with EPO deficiency, reticulocytosis is lower than it could be predicted based on the observation of patients with normal EPO levels and similar blood loss.

Secondary Hypertension, Erythrocytosis, and Unilateral Renal Cystic Disease in a Submariner: A Case Report

Erythrocytosis, or increased red blood cell mass, may be primary as in the case of polycythemia vera (PV), or secondary due to a variety of causes related to erythropoietin (EPO) secretion and hypoxia. Chronic pulmonary disease and certain EPO-secreting tumors should be addressed and excluded early during the course of evaluation for a patient presenting with increased red blood cell mass. Inclusion of the JAK2 V617F gene mutation in the recent World Health Organization criteria for the diagnosis of PV allows for facilitated diagnosis and guides therapy. EPO levels can be helpful in diagnosis and guiding therapy, but in the case of cystic renal diseases, EPO levels are often not elevated, creating diagnostic uncertainty. This report describes a case of symptoms directly attributable to erythrocytosis in the setting of negative JAK2 mutation and normal EPO levels. The subsequent discovery of a large cystic renal kidney and PV were the leading diagnostic considerations.

Presence of Calreticulin Mutations in JAK2-Negative Polycythemia Vera

Calreticulin (CALR) mutations have recently been reported in JAK2- and MPL-negative Myeloproliferative Neoplasms (MPN), particularly essential thrombocythemia (ET) and primary myelofibrosis (PMF).The clinical course of sporadic CALR-mutated patients seems to be more indolent than that of JAK2-mutated patients. In contrast, no CALR mutation has been found in the 647 published cases of Polycythemia Vera (PV) patients tested. Consequently, CALR mutations were considered exclusive to JAK2 and MPL mutations. Since 98% of PV patients harbor a JAK2 mutation (mostly the V617F mutation in exon 14 and more rarely, in exon 12), the absence of CALR mutations in PV seemed logical. Here, we describe two JAK2V617F-negative PV patients who presented with a CALR mutation at the time of diagnosis.Patient # 1 had hemoglobin at 168 g/L, hematocrit at 51.3%, and increased red cell mass (RCM) at 128% associated with a normal erythropoietin level. The bone marrow biopsy showed hypercellularity for age, panmyelosis associated with normal megakaryocytes and rare isolated abnormal enlarged forms. Using reticulin stain, no myelofibrosis was noted. Patient # 2 had hemoglobin at 194 g/L, hematocrit at 53% and low erythropoietin level without any dehydration. Both had moderately elevated platelet counts (658 and 575 x109/L respectively) with normal leukocyte counts. They were negative for BCR-ABL. No mutation was found in JAK2 exons 12, 13 and 14 by HRM and allele-specific real-time PCR or in MPL exon 10. Using HRM analysis, CALR mutations were suspected in both patients and confirmed using Sanger sequencing and product sizing analyses: CALR mutations were in both patients type 1 deletions (52-bp deletion; c.1092_1143del). To complete genomic tests made on peripheral blood granulocytes, we performed colony assays in methylcellulose and in collagen, picked single BFU-E colonies grown after 14 days in the presence of erythropoietin, and genotyped each colony individually for CALR. Of the 27 colonies genotyped, 6 had no PCR amplification and 21 harboured the same CALR mutation observed in peripheral blood granulocytes, i.e 52-bp deletion; c.1092_1143del. BFU-E were found heterozygous for CALR, with a mean allele burden of 49%. To our knowledge, these patients are the first cases of CALR-mutated PV to be reported. However, since a biclonalJAK2V617F and CALR MPN case recently reported, we cannot rule out the possibility of a biclonal disease involving a yet unknown mutation associated with a CALR mutation. On the other hand, the presence of a CALR mutation both in peripheral granulocytes and in BFU-E suggests that the CALR mutation plays a role in the polycythemia phenotype. Our observations highlight the fact that in the absence of JAK2 mutation, CALR mutations can also be associated with PV.In conclusion, our data indicate that testing JAK2-negative PV patients for CALR mutations may be useful. DisclosuresNo relevant conflicts of interest to declare.

Erythrocytosis and Normal Erythropoietin Levels In a 3 Year Old Female With High-Risk Neuroblastoma

Introduction Erythrocytosis has been reported in a number of cancers as a result of tumor production of Erythropoietin (EPO). There has been one reported case that we are aware of in a pediatric patient with neuroblastoma (Wang LY, et al. J Pediatr Hematol Oncol. 2003 Aug;25(8):649-50). Erythrocytosis in a pediatric neuroblasotoma patient with normal EPO levels, which is the subject of this case report, has not been reported previously. Case A three year-old female presented with a right sided abdominal pain of one week duration as well as constipation and decreased appetite of one month duration. Radiology studies showed a large abdominal mass, which turned out to be a poorly differentiated high-risk neuroblastoma on an incisional biopsy. For the first three months of this patient’s therapy and despite intense chemotherapy she was noted to have abnormally high hemoglobin levels. The peak hemoglobin level was 18 g/dL but she maintained hemoglobin levels greater than 14g/dL, which was greater than the 97th percentile for her age group (Dallman PR, et al. J Pediatr. 1979 Jan;94(1):26-31). Testing for EPO when the hemoglobin level was elevated showed a level of 8.1 mIU/ml, which was within the normal range for the patient’s age group (Krafte-Jacobs B, et al. J Pediatr. 1995 Apr;126(4):601-3). After tumor resection but before the conclusion of the myleosuppressive chemotherapy, hemoglobin levels fell below 10 for the majority of time. Discussion Although there has been a case reported of a pediatric patient with neuroblastoma having erythrocytosis, this is the first case where the patient was actually found to have normal EPO levels. Case reports looking at EPO and erythrocytosis in children with Wilms tumors have reported a couple cases of children who had normal EPO levels (Lal A, et al. J Pediatr Hematol Oncol. 1997 May-Jun;19(3):263-5). This report showed no recurrence of polycythemia when the tumors were removed in these patients. The authors concluded that tumor or surrounding renal tissue was at some point producing EPO despite their inability to detect it. Conclusion We speculate that neuroblastoma tumors and possibly other pediatric tumors may be releasing a novel erythropoietic cytokine. Hormone-like cytokines have been reported with other cancers, such as hypercalcemia produced by PTH related peptide in breast and lung cancers. More research is needed to determine what, if any, novel EPO-like hormones are being released by neuroblastoma cells resulting in erythrocytosis despite normal EPO levels. Disclosures: No relevant conflicts of interest to declare.

Erythrocytosis Post Allogeneic Stem Cell Transplantation, An Observational Study Of Hemoglobin Levels On Long-Term Follow Up Post Transplantation In Patients With Fanconi Or Acquired Aplastic Anemia

Post-transplant erythrocytosis is an ominous complication of kidney transplantation, occurring in the first 8 to 24 months after surgery in 10% to 15% of transplant recipients; this is frequently associated with significant thromboembolic events and sometimes death. In patients undergoing allogeneic hematopoietic cell transplantation (HCT), erythrocytosis has not been previously well described. At our institution, we observed that some aplastic anemia (AA), and Fanconi anemia (FA) patients developed progressively increased hemoglobin (HB), hematocrit (HCT) and RBC readings on long term follow up. Thus, this study was conducted to assess the validity of this observation in AA/FA patients post HCT, and its impact on their health. Patients and Methods From January 1993 until December 2011, 144 pediatric patients underwent successful allogeneic HCT for AA or FA; median age at HCT 11.6 years (range, 6.6 -15). All patients included were alive at the time of the analysis, and had sustained engraftment; all have had a follow up time of ≥ 12 months. For those who underwent more than one HCT, only events after the last HCT were included. We retrospectively examined the HB levels as an indicator for erythrocytosis (Corresponding RBC, HCT, WBC, and platelet counts were also collected). HB values of 150, and 160 gm/l were considered the trigger value in females and males, respectively. Patients who reached this value were studied for higher values on follow up, and only those whose HB persisted for at least 3 months above trigger value were included in the analysis; 29 patients (15 females, 14 males) were identified after causes of secondary erythrocytosis were ruled out. Erythrocytosis was defined as HB ≥ 160 gm/l in females, a HB ≥ 170 gm/l in males. Results Median time to trigger HB was 51.4 months (range, 15-121) in females, and 65 months (range, 23.3-114) in males, and median age at trigger HB was 14.7 years (range, 8.6-21.4) in females, and 16.9 years (range, 13.4-20.6) in males. Median highest HB reached was 160 gm/l (range, 151-162) in females, and 172 gm/l (range, 164-189) in males, with a median time of 67 months (range, 17-164) in females, and 103 months (range, 23.3-206) in males; the median age at highest HB was 16 years (range, 9.7-24.8) in females, and 20.2 years (range, 13.4-27.4) in males. Upon follow up, the HB fell below the trigger level in 16 patients (9 females, 7 males) (55.2%), at a median time of 37.2 months from the trigger value (range, 3.6-104). Seventeen patients qualified for the diagnosis of erythrocytosis (12%); 8 females, and 9 males. In all 8 females and in 4 males, HB fell below the erythrocytosis value upon follow up. All HB values correlated positively with HCT and RBC, no correlation was detected with platelet count or WBC. On univariate analysis, patients with older age at HCT (≥ 10 years) appeared to be more likely to develop elevated HB (P=0.003); and those who had radiation in the conditioning regimen were less likely to develop elevated HB (P=0.008). Three of the males with persistent erythrocytosis were tested further and all 3 had normal erythropoietin levels and were negative for JAK-2 mutations. None of the 29 patients had any adverse clinical symptoms during the follow up visits, and no thromboembolic events were reported. Conclusion A proportion of patients with AA/FA who undergo HCT may experience elevated HB on long term follow up; 12% subsequently qualifying as erythrocytosis, with the highest reading requiring between 1.5-2 years to evolve. Unlike erythrocytosis post renal transplant, the phenomenon we are describing in our patient cohort does not appear to be associated with any adverse symptoms, or any increased risk of thrombosis. More in depth investigation to study the potential pathophysiology behind it is currently underway at our institution, together with further exploration of this observation in patients with other illnesses undergoing allogeneic HCT. Disclosures: No relevant conflicts of interest to declare.

Determining level of endogenous serum erythropoietin for differential diagnosis of polycythemia vera and symptomatic polycythemia

The article deals with determining possibility of the assessment of the level of endogenous serum erythropoietin (EPO) for differential diagnosis of polycythemia vera (PV) and secondary erythrocytosis (SE). The determination of subnormal level of this cytokine for the diagnosis of PV has been detected. The relation between the level of endogenous erythropoietin and iron metabolism also has been analyzed. The study involved 88 patients with PV and 119 patients with SE. Statistically significant decrease in EPO concentration level has been detected in PV patients. The mean EPO level was equal to 6.38 ± 0.84 mIU/mL and 17.98 ±2.48 mIU/mL in PV and SE patients respectively. In control group of individuals EPO concentration was equal to 9,81 ±0,58 mIU/mL, the significant difference was found between all studied groups (р<0.01). According to our data, EPO was increased in 28 SE patients (23.53%), it was not observed in control group and in group of PV patients (φ*emp = 4.355, р<0.01). The decrease of EPO level in PV patients has been detected more often than in SE patients (84.09% versus 11.76% , φ*emp = 5.218, р<0.01), it has not been observed in control group. Only 14 (15.91%) PV patients had normal EPO level, in contrast 77 (64.71%) SE patients demonstrated normal EPO level (φ*emp = 4.578, р<0.01). The average level of ferritin was equal to 57.41 ± 9.74 ng/mL in PV patients and 199.77 ± 14.32 ng/mL in SE patients (р<0.01). Significantly more patients with PV demonstrated decrease of ferritin level (31.81% versus 7.56%, φ*emp = 4.438, р<0.01). Patients with SE more often had raised level of EPO than PV patients (15.12% versus 4.54%, φ*emp = 2.453, р<0.01). The sensitivity of test with detecting of the reduced level of EPO for the diagnosis of PV was 84.1%, specificity - 87.4%, positive predictive value - 83.1%, negative predictive value - 88.1%. Normal range of EPO significantly (rs = 0,5494) correlated with decreased levels of serum ferritin in patients with polycythemia vera, which was caused by iron deficiency in a certain number of patients with PV.

Diagnosis and management of congenital and idiopathic erythrocytosis

An erythrocytosis occurs when there is an increased red-cell mass. The causes of erythrocytosis are divided into primary, when there is an intrinsic defect in the erythroid cell, and secondary, when the cause is extrinsic to the erythroid cell. An idiopathic erythrocytosis occurs when the increased red-cell mass has no identifiable cause. Primary and secondary defects can be further classified as either congenital or acquired causes. The diagnostic pathway starts with a careful history and examination followed by measurement of the erythropoietin (EPO) levels. This allows a division of those patients with a low EPO level, who can then be investigated for primary causes of erythrocytosis, and those with a normal or high EPO level, where the oxygen-sensing pathway needs to be explored further. Physiological studies in those with congenital defects in the oxygen-sensing pathway show many changes in the downstream metabolism adapting to the defect, which has a bearing on the management of the disorders. Low-dose aspirin and venesection to an achievable target are the main therapeutic options that can be considered in the management of erythrocytosis. Specific guidance on venesection options should be considered with certain causes such as high oxygen-affinity hemoglobins.

A nonsynonymous LNK polymorphism associated with idiopathic erythrocytosis

AbstractNo abtract.

Response to Letter Regarding Article, “Endogenous Erythropoietin and Outcome in Heart Failure”

HomeCirculationVol. 122, No. 10Response to Letter Regarding Article, “Endogenous Erythropoietin and Outcome in Heart Failure” Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBResponse to Letter Regarding Article, “Endogenous Erythropoietin and Outcome in Heart Failure” Anne M.S. Belonje, MD, Adriaan A. Voors, MD, PhD, Peter van der Meer, MD, PhD, Tiny Jaarsma, PhD and Dirk J. van Veldhuisen, MD, PhD Wiek H. van Gilst, PhD Anne M.S. BelonjeAnne M.S. Belonje Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands Search for more papers by this author , Adriaan A. VoorsAdriaan A. Voors Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands Search for more papers by this author , Peter van der MeerPeter van der Meer Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands Search for more papers by this author , Tiny JaarsmaTiny Jaarsma Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands Search for more papers by this author and Dirk J. van VeldhuisenDirk J. van Veldhuisen Department of Cardiology, University Medical Center Groningen, Groningen, the Netherlands Search for more papers by this author Wiek H. van GilstWiek H. van Gilst Department of Experimental Cardiology, University Medical Center Groningen, Groningen, the Netherlands Search for more papers by this author Originally published7 Sep 2010https://doi.org/10.1161/CIRCULATIONAHA.110.960831Circulation. 2010;122:e450We thank Dr Incalzi and coauthors for their thorough reading of our article.1 They raise an important issue on chronic obstructive pulmonary disease (COPD)–related arterial hypoxemia and its influence on erythropoietin production. We agree that besides the presence of heart failure (and its known comorbidities), other factors can influence the level of erythropoietin.However, in several clinical studies, no increase in erythropoietin was found in nonanemic patients with COPD compared with healthy control subjects.2,3 In our heart failure study population, 28% (167 of 605) were diagnosed with COPD, which is consistent with data from other heart failure studies.4 The presence of COPD did not influence erythropoietin levels in our study as assessed by univariable linear regression analysis (β=0.026; P=0.53). To evaluate whether COPD influenced mortality of all causes in this heart failure cohort, we adjusted our multivariable Cox regression model for the presence of COPD. The addition of COPD did not strengthen our model, and more important, COPD was not an independent predictor of prognosis (hazard ratio, 1.18; 95% confidence interval, 0.90 to 1.56; P=0.24). Finally, the presence of COPD in patients with higher-than-expected erythropoietin levels based on their hemoglobin value was not significantly higher compared with patients with low or normal levels of erythropoietin. From these results, we conclude that the presence of COPD had no significant influence on the data that we presented.DisclosuresDr Voors has received unrestricted research grants from Amgen and Ortho Biotech. Dr van Veldhuisen has received lecture fees from Amgen and is a member of the Executive Committee of the Darbepoetin Morbidity/Mortality Heart Failure Trial (RED-HF). The other authors report no conflicts. References 1 Belonje AM, Voors AA, van der Meer P, van Gilst WH, Jaarsma T, van Veldhuisen DJ. Endogenous erythropoietin and outcome in heart failure. Circulation. 2010; 121: 245–251.LinkGoogle Scholar2 John M, Hoernig S, Doehner W, Okonko DD, Witt C, Anker SD. Anemia and inflammation in COPD. Chest. 2005; 127: 825–829.CrossrefMedlineGoogle Scholar3 Sala E, Balaguer C, Villena C, Rios A, Noguera A, Nunez B, Agusti A. Low erythropoietin plasma levels during exacerbations of COPD. Respiration. 2010; 80: 190–197.CrossrefMedlineGoogle Scholar4 Hawkins NM, Petrie MC, Jhund PS, Chalmers GW, Dunn FG, McMurray JJ. Heart failure and chronic obstructive pulmonary disease: diagnostic pitfalls and epidemiology. Eur J Heart Fail. 2009; 11: 130–139.CrossrefMedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetails September 7, 2010Vol 122, Issue 10 Advertisement Article InformationMetrics https://doi.org/10.1161/CIRCULATIONAHA.110.960831 Originally publishedSeptember 7, 2010 PDF download Advertisement SubjectsCongenital Heart Disease

Genetic causes of erythrocytosis and the oxygen-sensing pathway

Idiopathic erythrocytosis is an uncommon disease, and is defined by an increase in red blood cell mass. The differential diagnosis of erythrocytosis is extensive, and can be divided into primary and secondary forms. Primary erythrocytoses are due to intrinsic defects in erythroid precursor cells and are characterized by low erythropoietin levels. Secondary erythrocytoses are extrinsic to erythroid progenitors and are characterized by either high or inappropriately normal erythropoietin levels. A distinct subset of secondary erythrocytoses are due to genetic mutations in key proteins of the oxygen-sensing pathway. These proteins constitute the core molecular machinery of oxygen-sensing with respect to red blood cell control. Apart from assigning physiologic roles for these proteins, studies of these rare mutations have (i) revealed the exquisite sensitivity of this pathway to genetic perturbations, (ii) highlighted important functional regions of the proteins, and (iii) provided a basis for potentially targeting this pathway for therapeutic benefit.

Hematocrit-Driven Referrals for Measurement of RBC Mass. Is the Natural History of Polycythemia Vera Changing?.

Red blood cell mass (RCM) elevation is the sine qua non for diagnosis of polycythemia vera (pvera). The Polycythemia Vera Study Group (PVSG) employed therapeutic phlebotomy to lower the HCT to <55% as initial therapy. In the current era of frequent blood testing, RCM is usually requested based only on a high HCT often <55%. Thus the natural history of pvera may be changing if it is being diagnosed at an earlier stage. We reviewed 101 consecutive patients referred in 2002–2003 for RCM testing to characterize RCM requests from a large community referral base. There were 61 men and 40 women with mean HCT<55% (Table 1). 20 had lung disease or were smokers, 3 presented with arterial or venous thrombosis, 7 had cancer, 2 had renal cysts. HCT of men was higher than HCT of women if RCM was normal, but HCT were equivalent between genders if RCM was elevated. HCT was higher in men (p=0.0010) and women (p<0.0001) if RCM was elevated versus normal. HCT elevation was similar in secondary polycythemia vs pvera in men (51.0±4.02 vs 54.3±6.23; p=0.3397) or women (50.5±4.80 vs 49.3±2.12; p=0.4762).Table 1HCT of patients referred for RCM measurementGenderWhole GroupNormal RCMHigh RCMnHCTnHCTnHCTMale6148.3 (47.8) ±4.894546.9 (47.2) ±4.01652.1 (51.3) ±5.16Female4045.0 (43.8)± 4.723243.3 (42.5) ±3.691050.0 (50.0) ±3.84p value0.0001<0.00010.4932HCT shown as Mean (Median) ±SDWe examined whether, despite a lower presenting HCT, those with normal RCM demonstrated PVSG criteria that justified referral to our Nuclear Medicine department. Only 7 of the 75 patients with normal RCM met at least 2 of the PVSG “B” criteria or had splenomegaly, thus might have been diagnosed with pvera had RCM been high (Table 2).Table 22 PVSG “B” criteria or splenomegaly and normal RCMGenderWBC ≥12KPLT ≥400KB12 ≥900≥ LAP 100SplenomegalyM14.4413640158“normal”M12.1585133653“normal”M9.4428113968“normal”M8.6132134315 cmM8.231249218617 cmF18.258271923“normal”F6.3226318“enlarged”F7.114681315.3 cmOverall, 10 of 40 women and 16 of 61 men had an elevated RCM: 4 women and 5 men with polycythemia vera; 6 women and 11 men with secondary polycythemia. One other man was diagnosed with polycythemia vera on the basis of a borderline elevated RCM (33.8 ml/kg), normal O2 Sat on room air, popliteal artery thrombosis, and 3 “B” criteria. Serum erythropoietin (EPO) was low at 2.6 mU/ml (ref range 4–16). He was receiving therapeutic phlebotomy for hereditary hemochromatosis when his RCM was measured. He was the only patient with pvera whose EPO was low (three others had normal EPO levels). The 11 patients with secondary polycythemia who had EPO measured had normal levels. In summary, the HCT was the primary criterion for RCM testing for 2/3 of these patients. Only 5 presented with HCT>55%; mean HCT was ~50% in patients with elevated RCM. The bottom quartile HCT of women with elevated RCM in our patient population was 48.7%. This is a sensitive “cut-off” for finding an elevated RCM (p<0.0001, Chi square with Yates correction). We conclude that patients are referred for RCM testing when a high HCT is found, but at HCT far below the original PVSG parameters. Therefore polycythemia vera is now diagnosed earlier and in mostly asymptomatic patients. A normal EPO level does not rule out a diagnosis of pvera. A HCT < 48.7% may not warrant the measurement of RBC mass.

Low Prevalence of JAK2 Val617Phe Mutation in Patients with Idiopathic Erythrocytosis.

Idiopathic Erythrocytosis (IE) is a frequent clinical condition (estimated prevalence 1.1 cases every 1,000 normal subjects), characterized by an absolute increase of red blood cell mass, without the diagnostic features of polycythemia vera (PV), secondary polycythemias and congenital erythrocytosis. The clinical course of IE is marked by a lower rate of thrombotic complications than observed in PV and a very low, if any, spontaneous transition to acute leukemia. The differential diagnosis between IE and PV may be sometimes difficult but it is clinically relevant, also because cytotoxic drugs, frequently used in PV, should be avoided in IE. The recent description of a Val617Phe mutation in the exon 12 of JAK2 gene in 74–97% of patients with PV may represent a reliable molecular marker to differentiate PV from IE. However, the prevalence of JAK2 mutation in patients with IE is presently unknown. For this reason, we evaluated JAK2 mutation on granulocyte DNA or RNA using an allele-specific PCR in 31 patients with IE (29 males, 2 females, median age 46 years, range 19–74) and results were compared with those of 31 patients with overt PV (16 males and 15 females, median age 56 years, range 34–74). PV was diagnosed according to the WHO criteria. At variance, cases with IE were identified by increased hematocrit (median 54%, range 50–61%) and red blood cell mass (>25% above mean normal predicted value), but normal leukocyte and platelet counts, normal arterial O2 saturation and chest X-ray, no splenomegaly by abdominal ultrasound scanning and normal erythropoietin level and PRV-1 expression on peripheral blood granulocytes. Both IE and PV patients were either newly diagnosed or established cases in follow-up. Median follow-up was 5.5 years (range 0–20) in IE and 4.1 years (range 0–17) in PV patients respectively. Twenty-eight patients with PV (90%) but only 3 with IE (10%) showed the JAK2 Val617Phe mutation (p<0.001). In 3 patients with PV (10%) but none with IE, the JAK2 mutation was homozygous. The annual incidence of thrombotic complications was 3.2% in PV vs. 0.85% patient-year in IE (p<0.05). Our data confirm the hypothesis that JAK2 mutation is an useful molecular test to distinguish IE from PV in the great majority of patients with absolute erythrocytosis. Patients with “JAK2negative IE” require a different therapeutic approach than those with the classical “JAK2 positive PV”, since the incidence of thrombosis appears to be different. The few patients (about 10%) with discordant molecular and clinical diagnosis (i.e. “JAK2positive IE” or “JAK2 negative PV”) deserve particular attention. The long period of observation of our “JAK2positive IE” patients (3, 8 and 20 years, respectively) seems to exclude that these cases may represent an early phase of PV. However, whether this molecular marker confers a more aggressive or different clinical behaviour in a small subgroup of IE patients remains to be demonstrated in larger prospective studies.