Diagnosis Of Paroxysmal Nocturnal Hemoglobinuria Research Articles

Paroxysmal nocturnal hemoglobinuria cells in patients with bone marrow failure syndromes.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired hematopoietic stem-cell disorder in which the affected cells are deficient in glycosylphosphatidylinositol (GPI)-anchored proteins. Paroxysmal nocturnal hemoglobinuria is frequently associated with aplastic anemia, although the basis of this relation is unknown. To assess the PNH status of patients with diverse marrow failure syndromes. Correlation of cytofluorometric data with clinical features. Hematology Branch, National Heart, Lung, and Blood Institute, Bethesda, Maryland. 115 patients with aplastic anemia, 39 patients with myelodysplasia, 28 patients who had recently undergone bone marrow transplantation, 18 patients with cancer that was treated with chemotherapy, 13 patients with large granular lymphocytosis, 20 controls who had received renal allografts, and 21 healthy participants. Patients with aplastic anemia, myelodysplasia, or renal allografts received antithymocyte globulin. Flow cytometry was used to assess expression of GPI-anchored proteins on granulocytes. Evidence of PNH was found in 25 of 115 (22%) patients with aplastic anemia. No patient with normal GPI-anchored protein expression at presentation developed PNH after therapy (n = 16). Nine of 39 (23%) patients with myelodysplasia had GPI-anchored protein-deficient cells. Abnormal cells were not detected in patients with constitutional or other forms of bone marrow failure or in renal allograft recipients who had received antithymocyte globulin. Aplastic anemia is known to respond to immunosuppressive therapy; in myelodysplasia, the presence of a PNH population was strongly correlated with hematologic improvement after administration of antithymocyte globulin (P = 0.0015). Flow cytometric analysis is superior to the Ham test and permits concomitant diagnosis of PNH in about 20% of patients with myelodysplasia (a rate similar to that seen in patients with aplastic anemia). The presence of GPI-anchored protein-deficient cells in myelodysplasia predicts responsiveness to immunosuppressive therapy. Early emergence of GPI-anchored protein-deficient hematopoiesis in a patient with marrow failure may point to an underlying immune pathogenesis.

The Use of Monoclonal Antibodies and Flow Cytometry in the Diagnosis of Paroxysmal Nocturnal Hemoglobinuria

We have characterized the erythrocytes, granulocytes, and platelets of 54 patients with paroxysmal nocturnal hemoglobinuria (PNH) with antibodies to glycosylphosphatidylinositol-anchored proteins (anti-CD55, anti-CD59, and anti-CD16) and flow cytometry to establish the usefulness of this technique in the diagnosis of this disorder. All patients demonstrated either completely (PNH III) or partially (PNH II) deficient red cells and granulocytes. Anti-CD59 best demonstrated PNH II red cells, which were present in 50% of the patients. The proportion of abnormal granulocytes was usually greater than the proportion of abnormal red cells; 37% of the patients had >80% abnormal granulocytes. Anti-CD55 did not delineate the erythrocyte populations as well as did anti-CD59. Either anti-CD55 or anti-CD59 could be used equally well to analyze granulocytes; anti-CD16 did not demonstrate cells of partial deficiency. Platelets could not be used for detailed analysis as the normal and abnormal populations were not well distinguished. Flow cytometry of erythrocytes using anti-CD59 or of granulocytes using either anti-CD55 or anti-CD59 provides the most accurate technique for the diagnosis of paroxysmal nocturnal hemoglobinuria; it is clearly more specific, more quantitative, and more sensitive than the tests for PNH that depend upon hemolysis by complement (the acidified serum lysis [Ham] test, the sucrose lysis test, and the complement lysis sensitivity [CLS] test).

Acute leukaemia in paroxysmal nocturnal haemoglobinuria. Case report and review of the literature

Paroxysmal nocturnal haemoglobinuria (PNH) terminating in acute leukaemia (AL) is an infrequent condition. In several cases, flow cytometric analysis of glycosylphosphatidylinositol anchored membrane proteins such as DAF and CD59/MACIF has suggested the leukaemic cells to be derived from the PNH clone, thereby implicating PNH as a potential preleukaemic disease. In the present paper, we review the data for one patient treated in our hospital and 20 cases reported in the literature from 1969 to 1993. The sex ratio is 1 female/2 males, mean age at diagnosis of PNH was 46 years and the mean interval between the diagnoses of PNH and AL was 53 months. AL type was AML M6 in 8 patients, other types of AML in 12 and ALL in one, with a mean survival of 7.1 months following diagnosis of AL. In all cases analyzed, the PNH phenotype of erythrocytes disappeared with progression of AL, whereas reappearance of this phenotype with complete remission of AL was inconstant. PNH would thus appear to be a potential preleukemic disease. When this disorder terminates in AL, the type is often AML M6, although ALL is also possible. The prognosis of AL in PNH is poor as for other secondary leukaemias. Apart from marrow aplasia, leukaemic transformation is another life threatening complication of PNH which may justify allogeneic bone marrow transplantation (allo-BMT) and potential leukaemic transformation can therefore be an additional argument in favour of allo-BMT when pancytopenia develops in PNH patients.

Markedly High Population of Affected Reticulocytes Negative for Decay-Accelerating Factor and CD59 in Paroxysmal Nocturnal Hemoglobinuria

Paroxysmal nocturnal hemoglobinuria (PNH) blood cells lack glycosylphosphatidylinositol-anchored membrane proteins such as decay-accelerating factor (DAF) and CD59. This lack is of diagnostic value in PNH. Because reticulocytes in PNH are not yet well characterized, we analyzed reticulocytes obtained from 12 patients with PNH and from 5 healthy volunteers by two-color flow cytometry with a membrane-permeable fluorescent dye, thiazole orange, to identify reticulocytes and monoclonal antibodies to DAF and CD59. Healthy individuals had no affected cells. In all patients, the population of affected reticulocytes negative for DAF and CD59 was markedly higher than the population of affected erythrocytes. Moreover, the population of affected erythrocytes became obviously low in patients who received transfusions and suffered from hemolytic precipitation, whereas the population of affected reticulocytes was unchanged. The persistently high population of affected reticulocytes, despite cytolytic exclusion and an inherently short lifetime, might possibly be explained by relative reticulocytosis caused by an anemia-induced feedback stimulation of erythropoiesis in PNH. Thus, affected reticulocytes could be a reliable marker for the diagnosis of PNH and for the evaluation of erythropoiesis by PNH stem cell.

Paroxysmal Nocturnal Hemoglobinuria

This article, the fourth in a continuing education update series on hematology, reviews paroxysmal nocturnal hemoglobinuria (PNH), a clonal marrow stem cell disorder that involves erythroid, myeloid, megakaryocytic, and some lymphoid lineage. The disorder is sometimes classified as a chronic myeloproliferative syndrome because of its potential to transform into acute leukemia or one of the myelodysplastic syndromes. Clinically, the disorder manifests and is sometimes classified as a chronic hemolytic anemia. The disorder expresses itself as chronic hemolytic anemia, variable cytopenias, and venous thrombosis. Paroxysms of nocturnal hemoglobinuria occur in a minority of patients. The disorder is strongly associated with aplastic anemia, which may precede, develop concurrently with, or appear after the diagnosis of PNH.

Clinical Features and Diagnosis of Paroxysmal Nocturnal Hemoglobinuria: Correlates with the Deficiency of GPI-anchored Membrane Proteins

Clinical Features and Diagnosis of Paroxysmal Nocturnal Hemoglobinuria: Correlates with the Deficiency of GPI-anchored Membrane Proteins

Diagnosis of paroxysmal nocturnal haemoglobinuria by phenotypic analysis of erythrocytes using two-colour flow cytometry with monoclonal antibodies to DAF and CD59/MACIF.

We investigated the relationship between the complement lysis sensitivity test and two-colour flow cytometric analysis using monoclonal antibodies to decay accelerating factor (DAF) and CD59/membrane attack complex inhibitory factor (MACIF) in patients with paroxysmal nocturnal haemoglobinuria (PNH) and other haematological diseases. Flow cytometry showed that all 59 PNH patients had two or three erythrocyte populations, while all 74 patients with other haematological diseases and all 31 healthy volunteers had a single erythrocyte population. We compared the percentage of PNH III erythrocytes in the lysis test with the percentage of negative cells shown by flow cytometry in 52 PNH patients, and found a significant correlation (r = 0.960, P < 0.001). However, in 13 patients the erythrocyte phenotypes did not correspond in both tests. This was generally related to difficulty of detecting PNH II erythrocytes in the lysis test. In the PNH patients the ranges of mean fluorescence intensity for the negative, intermediate and positive erythrocyte populations were respectively 1.1-2.5, 2.2-29, and 61-600 for CD59/MACIF positivity and 1.9-7.2, 3.6-22. and 31-350 for DAF positivity. In contrast, the mean intensities in healthy volunteers ranged from 190 to 720 for CD59/MACIF and from 150 to 350 for DAF. These findings suggest that PNH can be diagnosed and phenotypic analysis of PNH erythrocytes can be performed by respectively assessing the fluorescence profiles and mean fluorescence intensities of both proteins using flow cytometry. Flow cytometry may provide a superior diagnostic method to the traditional tests for PNH.

Diagnosis of paroxysmal nocturnal haemoglobinuria using immunophenotyping of peripheral blood cells

Paroxysmal nocturnal haemoglobinuria (PNH) is now generally accepted as a disease in which bone marrow derived cells are deficient in phosphatidylinositolglycan (PIG)-anchored surface molecules. A series of new monoclonal antibodies detecting PIG-anchored surface structures on human leucocytes (CD48, CD55, CD59) has recently been described. In the present study 12 patients with the diagnosis PNH and a positive Ham test were examined for PIG-anchored surface antigen expression on various cell lineages using immunofluorescence. In all patients deficient cells were detected in erythrocyte, granulocyte and monocyte analysis. A deficient lymphocyte subset was also observed in all but one of these patients. Using two-colour analysis, all lymphocyte subpopulations such as T, B and NK cells were found to be affected. In addition, peripheral blood cells of 22 patients with severe aplastic anaemia (SAA) were tested for the PIG-anchoring defect. In five of these patients the defect was detected, and in four of the five the lack of PIG-anchored molecules was confined to the granulocyte and monocyte lineages apparently without affecting the erythrocytes. The results of these studies demonstrate that cytofluorographic testing of peripheral blood cells provides a simple and reliable method for establishing the diagnosis of PNH. Furthermore, especially in the case of aplastic anaemia patients, the sensitivity of immunophenotyping might be superior to conventional laboratory tests.

Paroxysmal Nocturnal Hemoglobinuria

A case of paroxysmal nocturnal hemoglobinuria (PNH) is presented in which MR imaging and CT findings were characteristic. The signal intensity of renal cortex was lower than that of medulla on both T1- and T2-weighted imaging. On CT without contrast enhancement the attenuation of renal cortex was higher than that of renal medulla. These findings at MR imaging and CT were the results of a deposition of hemosiderin in the cells of proximal convoluted tubules, and were helpful for diagnosis of PNH.

A Case Report of Paroxysmal Nocturnal Hemoglobinuria in a Child

A ten-year-old boy with paroxysmal nocturnal hemoglobinuria (PNH) is described. Although hemolytic anemia was evident, Ham's test was negative and the erythrocyte acetylcholinesterase (ACHE) activity was normal at the first admission. The diagnosis of hemolytic anemia of unknown etiology was made. Methylprednisolone pulse therapy was started, but could not prevent the hemolytic crises associated with infections. Twelve months later Ham's test turned positive and ACHE activity decreased. The diagnosis of PNH was confirmed. As the disease is insidious in onset, we emphasize that a high index of suspicion and Ham's test and sucrose water test repeated at regular intervals are required to avoid missing the diagnosis.

Deficiency of Glycosyl-Phosphatidylinositol-Linked Membrane Glycoproteins of Leukocytes in Paroxysmal Nocturnal Hemoglobinuria, Description of a New Diagnostic Cytofluorometric Assay

Paroxysmal nocturnal hemoglobinuria (PNH) is a disease that affects not only red cells, but other blood cells as well. The common defect is supposed to be an acquired deficiency of glycosyl-phosphatidylinositol (GPI)-anchored membrane proteins, which may be present already at the hematopoietic stem cell level. Recently, a panel of monoclonal antibodies (MoAbs) has become available directed against various GPI-linked membrane proteins. This makes it possible to study various cell lineages for the deficiency of such proteins in PNH in more detail. Using cytofluorography, we could show that the granulocytes of 20 different PNH patients miss not only GPI-linked FcRIII (CD16 antigen), but also three other GPI-linked proteins, ie, CD24 antigen, CD67 antigen and a granulocyte-specific 50 to 80 Kd antigen. The affected granulocytes were not only neutrophils but also eosinophils, as was found in a more detailed analysis of three patients. Moreover, in all 10 PNH patients tested, the monocytes were found to be deficient for the GPI-linked CD14 antigen, and we found with CD24 and CD55 (DAF) antibodies that lymphocytes may be involved as well. However, abnormal B and T lymphocytes were detected only in a subset of patients (2 of 10 tested). The uniform deficiency of GPI-linked proteins of granulocytes allows the introduction of a new diagnostic cytofluorometric assay for PNH with MoAbs against GPI-linked granulocytic antigens. This test was positive in all PNH patients studied and not in a group of 40 control patients or 50 normal donors, with the exception of three of 16 aplastic anemia (AA) patients. In the three AA patients, subpopulations (10% to 20%) of PNH granulocytes could be detected, whereas these patients had a negative acidified serum (Ham) test. This indicates that the new test is more sensitive than the Ham test and allows the early diagnosis of PNH in AA. An advantage of the neutrophil assay is that, in contrast to the Ham test, it is not influenced by recent red-cell transfusions. Moreover, it is possible to quantify the number of affected cells by single cell analysis.

Deficiency of glycosyl-phosphatidylinositol-linked membrane glycoproteins of leukocytes in paroxysmal nocturnal hemoglobinuria, description of a new diagnostic cytofluorometric assay

Paroxysmal nocturnal hemoglobinuria (PNH) is a disease that affects not only red cells, but other blood cells as well. The common defect is supposed to be an acquired deficiency of glycosyl-phosphatidylinositol (GPI)-anchored membrane proteins, which may be present already at the hematopoietic stem cell level. Recently, a panel of monoclonal antibodies (MoAbs) has become available directed against various GPI- linked membrane proteins. This makes it possible to study various cell lineages for the deficiency of such proteins in PNH in more detail. Using cytofluorography, we could show that the granulocytes of 20 different PNH patients miss not only GPI-linked FcRIII (CD16 antigen), but also three other GPI-linked proteins, ie, CD24 antigen, CD67 antigen and a granulocyte-specific 50 to 80 Kd antigen. The affected granulocytes were not only neutrophils but also eosinophils, as was found in a more detailed analysis of three patients. Moreover, in all 10 PNH patients tested, the monocytes were found to be deficient for the GPI-linked CD14 antigen, and we found with CD24 and CD55 (DAF) antibodies that lymphocytes may be involved as well. However, abnormal B and T lymphocytes were detected only in a subset of patients (2 of 10 tested). The uniform deficiency of GPI-linked proteins of granulocytes allows the introduction of a new diagnostic cytofluorometric assay for PNH with MoAbs against GPI-linked granulocytic antigens. This test was positive in all PNH patients studied and not in a group of 40 control patients or 50 normal donors, with the exception of three of 16 aplastic anemia (AA) patients. In the three AA patients, subpopulations (10% to 20%) of PNH granulocytes could be detected, whereas these patients had a negative acidified serum (Ham) test. This indicates that the new test is more sensitive than the Ham test and allows the early diagnosis of PNH in AA. An advantage of the neutrophil assay is that, in contrast to the Ham test, it is not influenced by recent red-cell transfusions. Moreover, it is possible to quantify the number of affected cells by single cell analysis.

Paroxysmal nocturnal hemoglobinuria and the transfusion of washed red cells. A myth revisited.

Paroxysmal nocturnal hemoglobinuria (PNH) is an uncommon, acquired clonal stem cell disorder primarily affecting red cells that have an abnormal sensitivity to complement lysis. Since 1948, the use of saline-washed red cells (WRBCs) has been advocated to minimize hemolysis after transfusion to patients with PNH. Thirty-eight years of experience (1950 through 1987) with patients who had PNH were reviewed. Twenty-three patients with a positive Ham's test had been transfused with 556 blood components, including 431 RBC products: 94 units of whole blood, 208 units of packed RBCs, 80 units of white cell-poor RBCs, 38 units of WRBCs, 5 units of frozen RBCs, and 6 units of intraoperatively salvaged RBCs. Only one documented episode of posttransfusion hemolysis related to the underlying diagnosis of PNH was found, and it was associated with the transfusion of a unit of type O whole blood to an AB-positive individual. This unit contained ABO-incompatible plasma; this case was similar to one in an earlier report from which originated the recommendation for using WRBCs. The posttransfusion increment in hemoglobin concentration in patients receiving ABO-identical packed RBCs was comparable to that in patients receiving frozen or washed RBCs. These findings indicate that the use of WRBCs is unnecessary and that patients with PNH should be transfused with group-specific blood and blood products.

Paroxysmal Nocturnal Hemoglobinuria: Termination in Acute Monocytic Leukemia and Reappearance after Chemotherapy with N4-Palmitoyl-l-β9-D-Arabinofuranosylcytosine (PL-AC) and Vincristine

Acute monocytic leukemia developed in a 77-year-old woman about 18 months after a diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) had been made. The classical features of PNH disappeared with the onset of the leukemia. Chemotherapy with N4-palmitoyl-1-beta-D-arabinosylcytosine and vincristine resulted in the disappearance of leukemic cells in the bone marrow, during which time intravascular hemolysis recurred and the results of a Ham's test were again positive. The anemia and thrombocytopenia, however, were not improved. The present case report suggests the disappearance of the leukemic cells to imply not bone marrow remission but the return of PNH.

Potential Errors in the Laboratory Diagnosis of Paroxysmal Nocturnal Hemoglobinuria

In a retrospective study of laboratory tests for paroxysmal nocturnal hemoglobinuria (PNH), the red blood cells of several patients gave conflicting results when different testing procedures were used. To resolve these discrepancies, an examination of the various procedures was undertaken, using sulfhydryl reagent-treated red blood cells as model PNH cells. Rabbit antiserum to human red blood cells was used to sensitize erythrocytes for specific antibody-dependent complement lysis sensitivity tests. Acidified serum and inulin were used in fluid-phase complement activation tests. For the general laboratory, a modification of the sucrose lysis test is described, which can give the relative complement sensitivity and size of an abnormal subpopulation of red blood cells. Considering the results of our patients and the reports in the literature of the association of PNH with a variety of lymphoproliferative and myeloproliferative disorders, it is stressed that testing procedures for PNH be controlled more carefully for a better understanding of the nature of the membrane defect.

Visual perseveration following temporal lobe surgery Case report

A 26-year-old man with the diagnosis of paroxysmal nocturnal hemoglobinuria presented with papilledema due to increased intracranial pressure without localizing neurological signs. It is concluded that papilledema and benign intracranial hypertension could result from a cerebral vein thrombosis which can complicate the course of paroxysmal nocturnal hemoglobinuria. This has not been a well-recognized feature of the disease.

Potential Errors in the Laboratory Diagnosis of Paroxysmal Nocturnal Hemoglobinuria

In a retrospective study of laboratory tests for paroxysmal nocturnal hemoglobinuria (PNH), the red blood cells of several patients gave conflicting results when different testing procedures were used. To resolve these discrepancies, an examination of the various procedures was undertaken, using sulfhydryl reagent-treated red blood cells as model PNH cells. Rabbit antiserum to human red blood cells was used to sensitize erythrocytes for specific antibody-dependent complement lysis sensitivity tests. Acidified serum and inulin were used in fluid-phase complement activation tests. For the general laboratory, a modification of the sucrose lysis test is described, which can give the relative complement sensitivity and size of an abnormal subpopulation of red blood cells. Considering the results of our patients and the reports in the literature of the association of PNH with a variety of lymphoproliferative and myeloproliferative disorders, it is stressed that testing procedures for PNH be controlled more carefully for a better understanding of the nature of the membrane defect.

Paroxysmal Nocturnal Hemoglobinuria

In a 71-year-old man, acute myelomonocytic leukemia developed six years after a diagnosis of paroxysmal nocturnal hemoglobinuria (PNH) had been established. The classic features of PNH disappeared with the onset of the leukemia. Chemotherapy resulted in complete leukemic remission, during which time intravascular hemolysis and a positive acidified serum (Ham's) test recurred; both findings again disappeared when the leukemia recurred. To our knowledge, this is the eighth reported case of PNH terminating in acute leukemia but is the first in which reappearance of PNH has been documented with leukemic remission. The alternating pattern of the two disorders suggests that the PNH clone survivors in the bone marrow when leukemia supervenes.

Paroxysmal nocturnal hemoglobinuria associated with infectious mononucleosis

A previously healthy 16-yr-old girl was found to have pancytopenia, low reticulocyte count, a cellular bone marrow, and a negative Coombs test, all coincident with clinical and laboratory evidence of infectious mononucleosis. Symptoms and signs of infectious mononucleosis subsided, but pancytopenia and hemolytic anemia persisted. Sucrose hemolysis and acid hemolysis tests supported a diagnosis of paroxysmal nocturnal hemoglobinuria (PNH). After 18 mo, the platelet count is normal, but leukopenia and hemolytic anemia continue. The development of PNH in this patient suggests it may have resulted from an effect of infectious mononucleosis.

Paroxysmal Nocturnal Hemoglobinuria Associated With Infectious Mononucleosis

A previously healthy 16-yr-old girl was found to have pancytopenia, low reticulocyte count, a cellular bone marrow, and a negative Coombs test, all coincident with clinical and laboratory evidence of infectious mononucleosis. Symptoms and signs of infectious mononucleosis subsided, but pancytopenia and hemolytic anemia per-sisted. Sucrose hemolysis and acid hemolysis tests supported a diagnosis of paroxysmal nocturnal hemoglobinuria (PNH). After 18 mo, the platelet count is normal, but leukopenia and hemolytic anemia continue. The development of PNH in this patient suggests it may have resulted from an effect of infectious mononucleosis.