Severe haemolysis and renal failure in a patient with paroxysmal nocturnal haemoglobinuria.

Transfusion of about 60 ml of ABO incompatible plasma in 4 units of pooled platelets precipitated severe haemolysis, unmasking the emergence of paroxysmal nocturnal haemoglobinuria (PNH), in a patient with aplastic anaemia. In vitro tests showed that her red cells were lysed by both ABO compatible and incompatible plasma from normal donors. The behaviour of this case and the in vitro results suggest that it might be hazardous to relax the longstanding recommendation on transfusing patients with PNH by restricting the washing of blood components to those containing ABO incompatible plasma.     

Mutation analysis of the PIG-A gene in Korean patients with paroxysmal nocturnal haemoglobinuria

AIM: Paroxysmal nocturnal haemoglobinuria (PNH) is caused by deficient biosynthesis of the glycosylphosphatidylinositol (GPI) anchor in haemopoietic stem cells. Mutation of the phosphatidylinositol glycan class A (PIG-A) gene, an X linked gene that participates in the first step of GPI anchor biosynthesis, is responsible for PNH. The characteristics of somatic mutation of the PIG-A gene in Korean patients with PNH were studied. METHODS: Twenty four patients with PNH were selected. Ham tests and sucrose haemolysis tests were carried out on all patients. The expression of CD59 in erythrocytes and granulocytes was investigated in 14 and five patients, respectively, to confirm the diagnosis. Dideoxy fingerprinting (ddF) was used to screen mutations, and direct sequencing of DNA was performed to characterise the mutations. RESULTS: Gene mutation was detected in 12 of the 24 patients. The other 12 patients were negative in ddF screening. Ten new mutations and two known mutations were detected. The mutations consisted of five deletions, six substitutions, and one insertion. These mutations resulted in six premature terminations, three abnormal splicings, one missense mutation in exon 2, and two nonsense mutations. Two patients with venous thrombosis showed mutations in exon 3 only. Substitution mutations were seen in six patients and frameshift mutations in the other six. CONCLUSIONS: There were 10 new mutations among the 12 mutations in the Korean patients with PNH and the characteristics of the mutations varied, with no significant hot spots in sites or types.     

Immunoregulatory cytokine polymorphisms in Italian patients affected by paroxysmal nocturnal haemoglobinuria and aplastic anaemia.

We investigated regulatory variants of five cytokine genes [tumour necrosis factor (TNF)-alpha, interferon (IFN)-gamma, transforming growth factor (TGF)-beta, interleukin (IL)-6 and IL-10] in 40 Italian patients affected by paroxysmal nocturnal haemoglobinuria (PNH) and aplastic anaemia (AA). Genotypes associated with high production of TGF-beta and IFN-gamma were more frequent in patients than in controls. Genetic regulation of the immunological pathways involved in the pathogenesis of bone marrow failure is suggested.     

阵发性睡眠性血红蛋白尿症与血栓发生的研究进展

阵发性睡眠性血红蛋白尿症(PNH)是一种克隆性造血干细胞功能紊乱所致罕见性骨髓功能衰竭性疾病,以血管内溶血性贫血,全血细胞减少和血栓为表现。PNH虽是良性疾病,但其并发症严重影响患者生活质量和生存时间,其中最常见严重并发症是血栓。     

Placental expression of glycophosphatidylinositol (GPI)-anchored proteins in paroxysmal nocturnal haemoglobinuria

Paroxysmal nocturnal haemoglobinuria (PNH) is a clonal stem cell disorder in which a defect of glycophosphatidylinositol (GPI)-anchored proteins leads to higher morbidity and mortality because of intravascular haemolysis, haemoglobinuria, pancytopenia and an increased frequency of thrombotic events. We report here the clinical features of a pregnant woman with PNH and present an immunhistochemical analysis of complement regulators, leukocyte activation markers and placental alkaline phosphatase (PALP) on syncytiotrophoblasts and inflammatory cells in her placenta. Placental tissue from normal deliveries served as controls. The patient had severe PNH with haemolysis, thrombosis episodes and signs of bone marrow failure. Placental syncytiotrophoblasts and villous cells of fetal origin in both normal placentas and the placenta from the PNH patient expressed PALP and the complement regulators CD46, CD55 and CD59. Additionally, CD11b-positive leukocytes of presumed maternal origin were negative for CD15 in the PNH placenta, while they stained positive within the villous space and in normal placentas. These findings show that fetally derived cells in the PNH placenta expressed GPI-linked molecules that are known to be of importance for a successful pregnancy outcome.     

Paroxysmal nocturnal haemoglobinuria in aplastic anaemia.

The syndrome of paroxysmal nocturnal haemoglobinuria is a stem cell disorder characterized by the production of abnormal cells in all three lines of the peripheral blood. These cells react abnormally with the activated components of complement, resulting in the clinical symptoms. The clone of stem cells characteristic of paroxysmal nocturnal haemoglobinuria may arise spontaneously without demonstrable abnormalities of the other stem cells of the bone marrow. On the other hand, the abnormal stem cells of paroxysmal nocturnal haemoglobinuria may arise as part of a prior stem cell disorder. This is especially true for aplastic anaemia. The paroxysmal nocturnal haemoglobinuria stem cell may arise at any time during the evolution from aplasia through recovery and may disappear during full recovery of the bone marrow. The paroxysmal nocturnal haemoglobinuria stem cell may arise less commonly in other disorders of the stem cell, such as refractory anaemia with excess blasts, erythroleukaemia and myelofibrosis. As with all disorders of the stem cells, paroxysmal nocturnal haemoglobinuria and aplastic anaemia may eventuate into acute leukaemia.     

Sarcoidosis associated with autoimmune haemolytic anaemia and paroxysmal nocturnal haemoglobinuria red cell abnormality

A 29-year-old male with sarcoidosis autoimmune haemolytic anaemia and paroxysmal nocturnal haemoglobinuria is described. Throughout his illness the chest films showed fibrosis in the right hilar region and he had had several pneumonias in the right lung. He had had massive splenomegaly and a splenectomy was performed. He was treated with prednisone and cyclophosphamide. Because his blood group was initially confused, several incompatible blood transfusions were given. Two types of antibody were detected: an autoantibody with "s" specificity and an alloantibody with Rh "D" specificity. Other interesting features in this case revealed at autopsy were a viral pneumonia and Toxoplasma gondii infection of the brain. As far as we know, this is the first reported patient with this unusual association.     

Immunoregulatory cytokine polymorphisms in Italian patients affected by paroxysmal nocturnal haemoglobinuria and aplastic anaemia

We investigated regulatory variants of five cytokine genes [tumour necrosis factor (TNF)‐α, interferon (IFN)‐γ, transforming growth factor (TGF)‐β, interleukin (IL)‐6 and IL‐10] in 40 Italian patients affected by paroxysmal nocturnal haemoglobinuria (PNH) and aplastic anaemia (AA). Genotypes associated with high production of TGF‐β and IFN‐γ were more frequent in patients than in controls. Genetic regulation of the immunological pathways involved in the pathogenesis of bone marrow failure is suggested.     

Idiopathic non-syphilitic paroxysmal cold haemoglobinuria in children.

Three examples of non-syphilitic paroxysmal cold haemoglobinuria (PCH) in children are described which occurred, within a period of 16 days, in association with a febrile illness. No definite viral aetiology or obvious epidemiological association could be established. A Donath-Landsteiner antibody of anti-P specificity was demonstrated in all three patients. The serological aspects of PCH are critically discussed.     

Assessing donor chimerism using flow cytometry in paroxysmal nocturnal haemoglobinuria after stem cell transplantation--a case report

Paroxysmal nocturnal haemoglobinuria (PNH) is an acquired haemopoietic stem cell disorder arising from somatic mutation of the X-linked PIG-A gene which leads to deficiency of the glycosylphosphatidylinositol (GP1) membrane anchor proteins such as CD 59 (MIRL: membrane inhibitor of reactive lysis) and CD 55 (DAF: decay accelerating factor). Allogeneic peripheral blood stem cell transplant (PBSCT) is a curative mode of treatment in symptomatic PNH patients. Assessment of donor chimerism for PBSCT can be performed by various methods including short tandem repeat loci (STR) and variable number of tandem repeats (VNTR). Flow cytometry, which is much cheaper and faster, also can be used to assess engraftment in patients with PNH. Engrafted patients will show the presence of CD 55 and CD 59 on their red cells and white cells. We describe here the usefulness of flow cytometry in the assessment of donor chimerism following allogeneic PBSCT, in a case of PNH.     

Erythrocytes of patients with paroxysmal nocturnal haemoglobinuria acquire resistance to complement attack by purified 20-kD homologous restriction factor.

A 20-kD homologous restriction factor (HRF20) which is a membrane inhibitor of the terminal stage of human complement action can be detected by the monoclonal antibody 1F5, and is deficient on abnormal erythrocytes as well as leucocytes from patients with paroxysmal nocturnal haemoglobinuria (PNH). The erythrocytes of PNH patients significantly improved their resistance to homologous complement after adsorption of purified HRF20.