Polycythemia and the Budd-Chiari syndrome: study of serum erythropoietin and bone marrow erythroid progenitors

The mechanism of polycythemia associated with the Budd-Chiari syndrome is unknown. Erythropoiesis in 10 patients with Budd-Chiari syndrome was studied in an attempt to distinguish prior unrecognized polycythemia vera from secondary polycythemia. Serum erythropoietin was assayed using a mouse fetal liver erythroblast assay. High concentrations of serum erythropoietin were observed in 6 of 7 patients with acute primary Budd-Chiari syndrome. Levels were normal in four patients who were investigated during the chronic phase and were increased in one with persisting polycythemia. In one patient, erythropoietin concentration in the hepatic vein was twice the level measured in peripheral, caval and renal venous blood. Bone marrow erythroid progenitors developed in vitro in the absence of exogenous erythropoietin in all polycythemia vera cases studied in acute and chronic phases, whether polycythemia persisted or not. These findings indicate that hepatic erythropoietin production occurs in the acute phase of Budd-Chiari syndrome and suggest that, in some cases of Budd Chiari syndrome, polycythemia which resolves after the acute phase may be secondary to liver disease.     

Plasma erythropoietin in polycythemia.

Erythropoietin titers of plasma cannot be used to differentiate polycythemia vera from secondary polycythemia since the limit of sensitivity of our current bioassay technics is 50 mU, considerably higher than levels found in normal subjects and in patients with polycythemia. However, erythropoietin is relatively heat stable, and since abundant plasma is available from therapeutic phlebotomies it is possible to prepare and assay highly concentrated, erythropoietin-containing extracts. In 35 normal subjects, erythropoietin levels ranged from less than 5 mU/ml (the limit of sensitivity) to 18 mU/ml with a mean of 7.8 mU/ml. In 21 patients with proved polycythemia vera, the levels were less than 5 mU/ml in all. In 41 patients with suspected secondary polycythemia or polycythemia of unknown origin, the levels ranged from less than 5 to 3,000 mU/ml. Three of the 11 patients with levels less than 5mU/ml were subsequently shown to have polycythemia vera. These results suggest that this refinement of the routine bioassay for erythropoietin may be of clinical importance in the differential diagnosis of polycythemia.     

Functional similarities of hepatic cystic and biliary epithelium: studies of fluid constituents and in vivo secretion in response to secretin

Hepatic cysts are a frequent manifestation of autosomal dominant polycystic kidney disease, but little is known about their functional characteristics. The goals of our study were to define the composition of hepatic cyst fluid and to determine whether hepatic cysts secrete in response to intravenously administered secretin. We percutaneously punctured five hepatic cysts and one proximal renal cyst from six subjects with autosomal dominant polycystic kidney disease and one solitary hepatic cyst from a subject without autosomal dominant polycystic kidney disease. Most fluids had an electrolyte composition similar to serum. Fluid from all hepatic cysts had glutamyltranspeptidase concentrations above those found in serum [( cyst]/[serum] = 4.93 +/- 5.92), contained secretory component (the epithelial receptor for polymeric IgA) and had glucose concentrations less than 15 mg/dl. Fluid from both hepatic and renal cysts of subjects with autosomal dominant polycystic kidney disease, but not from the subject with the solitary hepatic cyst, demonstrated extensive changes in the electrophoretic mobility of several serum proteins. Initial intracystic pressures ranged from 16 to 40 cm H2O, were reduced 57% to 97% after aspiration of a portion of cyst fluid and were held constant during the secretion study. Within 8 min of the intravenous administration of secretin, secretion of fluid increased in two of three hepatic cysts and in the renal cyst. The electrolyte composition of cyst fluids was not altered by secretin. These data suggest that hepatic cystic epithelium has functional characteristics of biliary epithelium and that secretion by both hepatic and renal cysts may be hormonally regulated.     

Erythrocytosis associated with renal artery thrombosis in a patient with polycystic kidney disease on hemodialysis

We report a case of erythrocytosis in a patient with end-stage renal failure on chronic hemodialysis. The patient with polycystic kidney disease had an average Hb level of 10 g/dl while on hemodialysis for 3 years. He developed erythrocytosis (Hb 17.6 g/dl) following a cadaveric renal transplantation. No signs suggesting polycythemia vera were found. Nonrenal causes of secondary erythrocytosis such as anoxia, hemoglobinopathies or tumors were excluded. Angiography showed renal artery occlusion of the native kidney. Serum erythropoietin level was 85 U/l (normal 52 +/- 31 U/l) as measured by 3H-thymidine uptake. It is suggested that ischemia caused by the renal artery thrombosis stimulated the erythropoietin production in the native polycystic kidney.     

The relationship of erythromonocytic leukemia to other myeloproliferative disorders

The evolution of erythromonocytic leukemia has been studied in two patients. One (Case 1) presented with DiGuglielmo's syndrome manifested by erythroid hyperplasia, dyserythropoiesis, periodic acid-Schiff-positive erythroblasts, normal heme biosynthesis and ineffective erythropoiesis. In vitro stimulation of the patient's bone marrow with exogenous erythropoietin demonstrated decreased responsiveness. Progressive infiltration of the bone marrow and peripheral blood with primitive monocytic cells was accompanied by an increased number of hypodiploid cells. The second patient (Case 2) presented with a picture of polycythemia vera, progressing to myelofibrosis and terminating as erythromonocytic leukemia in which a paroxysmal nocturnal hemoglobinuria-like defect was demonstrated in the erythroid cells. The leukemic cells were hyperdiploid. It is concluded that erythromonocytic leukemia may result from clonal evolution occurring in any of the myeloproliferative syndromes.     

Hypertension,hyperreninemia and a solitary renal cyst in an adolescent

Solitary renal cysts associated with hypertension and documented hyperreninemia are relatively uncommon. A 13 year old boy with these findings is described (pressure 160/120 mm Hg). Contrast studies of the urinary tract and arteriography with selective renal vein sampling demonstrated a solitary cyst in the right kidney. The ratio of plasma renin activity in the right renal vein to left renal vein (RRV:LRV) was 2.35:1. After drainage of the cyst, there was a marked reduction in both systolic and diastolic pressures (126/84 mm Hg). Hypertension has not recurred during 14 months' follow up.     

Plasma erythropoietin levels and acquired cystic disease of the kidney in patients receiving regular haemodialysis treatment

Acquired cystic disease of the kidney (ACDK) in patients with end-stage renal failure can be associated with development of polycythaemia. The relationship between plasma erythropoietin levels and ACDK in 17 patients on long-term haemodialysis treatment was studied. There was a significantly higher level of plasma erythropoietin in patients with multiple renal cysts than in those patients with less than five cysts or no cysts. Haemoglobin tended to be higher in the ACDK group, but the difference was not significant. These results indicate that the development of renal cysts results in increased secretion of erythropoietin.     

Erythropoietin-dependent primary pure erythrocytosis.

We investigated the pathogenesis of isolated erythrocytosis of 14 yr duration in a 28-yr-old man. The increase in red cell mass was attributed to increased erythropoietin production. An extensive search for recognized causes of secondary erythrocytosis was unrevealing. Family members were found to be hematologically normal. After reduction of the circulating red cell mass by 20%, erythropoietin activity nearly quadrupled, thus suggesting a normal erythropoietin response to phlebotomy. When bone marrow cells of the patient were cultured in plasma clots in the absence of added erythropoietin, endogenous erythroid colony formation was observed, a pattern previously believed to be specific for polycythemia vera bone marrow cells. Our observations suggest that the erythrocytosis in this individual is best explained by an abnormal "servoregulatory" mechanism of erythropoietin production. In addition, this is the first instance in which the rule that endogenous erythroid colony formation is correlated with the diagnosis of polycythemia vera has not held.     

Polycythemia vera and other primary polycythemias

PURPOSE OF REVIEW: Diagnosis and therapy of polycythemia vera are controversial since the molecular basis of polycythemia vera remains unknown. Distinguishing between polycythemia vera and other polycythemic disorders can be very challenging. The purpose of this review is to discuss the recent progress in this area and critically review the published data in context of our knowledge of other polycythemic disorders. RECENT FINDINGS: Erythropoietin is the principal regulator of regulator of erythropoiesis; its production is regulated by the degree of hypoxia. Our knowledge of cellular responses to hypoxia has recently exploded and led to the elucidation of the molecular basis of a polycythemia caused by augmentation of hypoxic sensing, Chuvash polycythemia. Similar progress in understanding the molecular basis of polycythemia vera has been elusive. A simple, readily available laboratory test to establish a diagnosis of polycythemia vera would be highly desirable; however, none exists. The value of quantization of neutrophil PRV-1 mRNA, platelet c-mpl expression, in vitro assays of erythroid progenitor cells, serum erythropoietin levels, establishing clonality in female subjects using assays employing X-chromosome-based polymorphism assays, and the progress in the chromosomal location of the gene is discussed. Integration of this information underlies the complexity of the molecular biology of polycythemia vera and indicates likely interaction of multiple genetic events in the genesis of polycythemia vera. SUMMARY: The existence of family clustering of PV may facilitate the search for PV molecular basis. Only collaborative interaction of clinical researchers and laboratory scientists will lead to meaningful progress in determining the molecular basis of PV.     

Regulation of Erythropoiesis. I. Erythropoietin Assay as a Clinical Tool

An erythropoietin assay using hypertransfused rats and radioiron utilizationhas been evaluated in regard to modifying factors and its variability. It isproposed that the dose-response relationship may be regarded as an adsorptiveprocess which suggests new investigative approaches in terms of hormonebinding sites and erythropoietin inhibition.

Elevated levels of erythropoietin were found in 14 of 16 patients withrefractory anemia indicating a basic defect in the response of the erythroidmarrow. The two exceptions are of great theoretical interest, but insufficientinformation limits further conclusions. Patients with hypoxic polycythemiademonstrated increased levels only when their compensatory equilibrium hadbeen modified by phlebotomy. Seven patients with polycythemia vera haderythropoietin levels within the normal range whether or not therapy hadmodified their red cell mass. This is further evidence that polycythemia vera isa proliferative disorder usurping the normal regulation. The clinical use oferythropoietin assay may provide the most information when correlated withalterations of oxygen-carrying capacity as a functional test of the patient’serythropoietic regulatory mechanism.

Submitted on February 5, 1962 Accepted on March 23, 1962     

Inappropriate erythropoietin secretion in polycythemia vera

A patient with classical polycythemia vera (PV) was found to have an inappropriately elevated serum erythropoietin (Ep) level. Investigations did not reveal any lesion or blood abnormality known to be associated with excessive Ep production and erythrocytosis. Sudden withdrawal of blood to reduce the Hb and Hct from 18.5 gm% and 56% to 13.6 gm% and 41.5%, respectively, resulted in an increment of serum Ep to abnormal level. With iron treatment there was a brisk return of Hb and Hct to prebleeding levels which was associated with reduction in the serum Ep. The inverse relationship between the EP and Hb or Hct is inconsistent with the presence of excessive Ep-producing lesion. These results suggested that the threshold for Ep secretion from normal Ep-secreting tissue to Hb and Hct levels is set at an abnormal level. This patient's marrow cells when cultured in vitro in the absence of Ep, unlike other PV patients' (except one) marrow cells, did not grow erythroid colonies. In the presence of Ep, however, the colonies comparable to those formed from normal marrow cultures were obtained. These results suggested that his marrow erythropoietic cells were neither Ep independent nor Ep-hyperresponsive, as has been suggested by some investigators for erythropoiesis in PV. This patient presents phenomena that hitherto have not been reported.     

Serum inhibitors of hematopoiesis in a patient with aplastic anemia and systemic lupus erythematosus. Recovery after exchange plasmapheresis.

A 36 year old black woman with serologic evidence of systemic lupus erythematosus had aplastic anemia that failed to respond to corticosteroid or androgen therapy. Bone marrow culture studies were performed to determine if the marrow aplasia was immunologically mediated. A potent serum inhibitor of in vitro myeloid and erythroid colony formation was demonstrated. Incubation of normal bone marrow cells with the patient's serum and a source of complement caused a 95 per cent reduction in myeloid colony formation. Under these conditions, bone marrow from 35 normal volunteer subjects formed a mean of 5 ± 1 colonies per 2 × 10⁵ marrow cells plated (control = 95 ± 8 colonies). The addition of the patient's serum plus complement to normal marrow cultured in methylcellulose also caused a 98 per cent reduction in erythroid colony numbers. Assay of serum immunoglobulin fractions obtained by gel filtration demonstrated that the inhibitory activity was contained in the immunoglobulin G (IgG) fraction. In association with a series of plasma exchanges, the titer of inhibitor fell, and marrow cellularity and peripheral blood counts returned to normal. Additional studies indicated that the inhibitor of allogeneic marrow was not directed against HLA or “B-cell” antigens. Incubation of the patient's recovery marrow with stored preplasmapheresis serum and complement did not produce a reduction in myeloid colony formation. It seems most likely that the inhibitor represents alloantibody directed against heretofore unrecognized antigens widely distributed on normal human hematopoietic progenitor cells.     

Immunopathologic features of a patient with glomerulonephritis and pulmonary hemorrhage

Described here is a patient who had pulmonary hemorrhage associated with glomerulonephritis. Serologic data revealed the presence of circulating cold agglutinins, a positive Coombs test and positive antinuclear factor. Serum total hemolytic complement levels and serum complement component Clq levels were low throughout the patient's course. The patient also exhibited precipitating antibodies against calf thymus nuclear extract and rabbit liver ribosomes. In addition, rheumatoid factor precipitable material was detected in the serum early in the patient's course. Immunofluorescent studies revealed deposition of immunoglobulin G (IgG) on the glomerulus in a pattern analogous to that which occurs in experimental “immune-complex” induced glomerulonephritis. Our findings suggest that the patient's disease was associated with circulating and deposited antigen-antibody complexes. The pathogenesis of the renal lesion in this instance is therefore distinctive from that previously described in patients with pulmonary hemorrhage and nephritis and said to have Goodpasture's syndrome, which is usually associated with antiglomerular basement membrane antibodies.     

Polycythemia in transgenic mice expressing the human erythropoietin gene.

Erythropoietin is a glycoprotein hormone that regulates mammalian erythropoiesis. To study the expression of the human erythropoietin gene, EPO, 4 kilobases of DNA encompassing the gene with 0.4 kilobase of 5' flanking sequence and 0.7 kilobase of 3' flanking sequence was microinjected into fertilized mouse eggs. Transgenic mice were generated that are polycythemic, with increased erythrocytic indices in peripheral blood, increased numbers of erythroid precursors in hematopoietic tissue, and increased serum erythropoietin levels. Transgenic homozygotes show a greater degree of polycythemia than do heterozygotes as well as striking extramedullary erythropoiesis. Human erythropoietin RNA was found not only in fetal liver, adult liver, and kidney but also in all other transgenic tissues analyzed. Anemia induced increased human erythropoietin RNA levels in liver but not kidney. These transgenic mice represent a unique model of polycythemia due to increased erythropoietin levels.     

Endogenous erythroid colony formation by peripheral blood mononuclear cells from patients with myelofibrosis and polycythemia vera.

Peripheral blood mononuclear cells from patients with polycythemia vera or myelofibrosis with myeloid metaplasia were studied for their erythroid colony growth characteristics in plasma clot cultures. In both diseases, erythroid colonies formed early in culture in the absence of added erythropoietin (endogenous colonies). In no instance did early, endogenous colony formation occur with peripheral blood cells from normals or patients with secondary polycythemia. A normal response to erythropoietin was observed with both control and patients' peripheral blood cells. Spleen mononuclear cells obtained from one patient with myelofibrosis also produced endogenous colonies and showed a response to erythropoietin. This study suggests that culture of peripheral blood mononuclear cells might serve as a useful tool in discriminating polycythemia vera from secondary polycythemia.     

Pure erythrocytosis classified according to erythropoietin titers

Erythropoietin titers, measured by bioassay of plasma extracts in hypertransfused mice, were determined in 162 patients with absolute erythrocytosis, and the results were correlated with the clinical diagnosis. Fifty-two patients met the diagnostic criteria for polycythemia vera, and all had low or nonmeasurable erythropoietin titers. Of the remaining 110 patients, 62 were suspected clinically as having secondary polycythemia. However, 15 had low erythropoietin titers, casting doubt on the accuracy of the clinical diagnosis. The pathogenesis of the erythrocytosis in the last 48 patients was unknown, and they were designated clinically as having pure erythrocytosis. However, in 20, the erythropoietin titers were increased, and in 28, the titers were low, suggesting that they belonged to at least two different groups. Using erythropoietin titers in the classification of absolute erythrocytosis, the first group should be added to the category of patients with secondary polycythemia as a subgroup with disease due to idiopathic overproduction of erythropoietin (hypererythropoietinemia or essential erythrocytosis). The second group should be added as a subgroup of patients with primary polycythemia under the term erythremia.     

Transition of Myelofibrosis to Polycythaemia Vera

A case of typical myelofibrosis with a huge spleen is described in a 62-year-old man. During the subsequent 2-year follow-up, a clinical picture of polycythaemia vera with pancytosis and disappearance of the marrow fibrosis was observed. The pancytosis necessitated treatment with busulphan and frequent phlebotomies. The transformation was associated with prednisone treatment for a suspected haemolytic state. During this treatment, the spleen no longer became enlarged on clinical palpation, although it was still enlarged at post mortem examination, but much less than 2 years earlier.     

Increased serum procollagen III aminoterminal peptide in myelofibrosis

Myelofibrosis has been shown to involve an increase in type III collagen in the marrow. The aminoterminal procollagen III (PC III) peptide fragment is released during the production of PC III by fibroblasts and its serum level is therefore a marker for type III collagen synthesis. Using a recently developed sensitive radioimmunoassay, serum levels of PC III peptide were measured in 30 patients with myeloproliferative disease and 23 normal volunteers. Levels were found to be elevated above normal values in patients with polycythemia vera, even more elevated in patients with polycythemia and evidence of secondary myelofibrosis with myeloid metaplasia, and most strikingly elevated in patients with agnogenic myeloid metaplasia and severe marrow fibrosis. There was a significant association between serum levels of PC III peptide and the extent of reticulin fibrosis in bone marrow biopsies. Serum PC III level appears to be a quantitative marker for myelofibrosis.     

Apoptosis and polycythemia vera

Polycythemia vera is an acquired clonal myeloproliferative disorder characterized by increased numbers of erythroid cells, often with a concomitant rise in neutrophils and/or megakaryocytes. Normally, erythropoietin is essential for the survival and proliferation of erythroid progenitors; however in polycythemia vera the erythroid progenitor cells can survive and develop in the absence of erythropoietin. Members of the Bcl-2 family of apoptosis regulators have been shown to mediate the erythropoietin-dependent survival of erythroid cells. In this article, recent advances in understanding the mechanisms used by erythroid progenitors from patients with polycythemia vera to control apoptosis, are discussed.     

Polycythemia vera masked due to severe iron deficiency anemia

Polycythemia vera is one of the chronic myeloproliferative diseases and very few patients present with its actual clinical manifestations. The most common findings are increased red cell mass and an increased leukocyte count with decreased erythropoietin. We present a case where there was a delay in the diagnosis of polycythemia because of menorrhagia in the past. On admission, the patient presented with elevated red and white blood cell counts, erythropoietin was low, and polycythemia was then suspected. A bcr-abl test was performed to rule out chronic myelogenous leukemia. JAK2 mutation was positive, and the patient was diagnosed with polycythemia vera.