Nocturnal Hemoglobinuria Clones Research Articles

Time and residual hematopoiesis are crucial for PNH clones escape in hepatitis-associated aplastic anemia.

The presence of paroxysmal nocturnal hemoglobinuria (PNH) clones in aplastic anemia (AA) suggests immunopathogenesis, but when and how PNH clones emerge and proliferate are unclear. Hepatitis-associated aplastic anemia (HAAA) is a special variant of AA, contrarily to idiopathic AA, in HAAA the trigger for immune activation is clearer and represented by the hepatitis and thus serves as a good model for studying PNH clones. Ninety HAAA patients were enrolled, including 61 males and 29 females (median age 21years). Four hundred three of idiopathic AA have been included as controls. The median time from hepatitis to cytopenia was 50days (range 0-180days) and from cytopenia to AA diagnosis was 26days (range 2-370days). PNH clones were detected in 8 HAAA patients (8.9%) at diagnosis and in 73 patients with idiopathic AA (IAA) (18.1%). PNH cells accounted for 4.2% (1.09-12.33%) of red cells and/or granulocytes and were more likely to be detected in patients with longer disease history and less severe disease. During follow-up, the cumulative incidence of PNH clones in HAAA increased to 18.9% (17/90). Nine HAAA patients newly developed PNH clones, including six immunosuppressive therapy (IST) nonresponders. The clone size was mostly stable during follow-up, and only 2 of 14 patients showed increased clone size without proof of hemolysis. In conclusion, PNH clones were infrequent in newly diagnosed HAAA, but their frequency increased to one that was similar to the IAA frequency during follow-up. These results suggest that the PNH clone selection/expansion process is dynamic and takes time to establish, confirming that retesting for PNH clones during follow-up is crucial.

Small PNH clones detected by fluorescent aerolysin predict a faster response to immunosuppressive therapy in patients with severe aplastic anaemia

ABSTRACT Objectives: To clear the obscure conclusion on the prediction value of paroxysmal nocturnal haemoglobinuria (PNH) clones in severe aplastic anaemia (SAA) patients treated with immunosuppressive therapy (IST). Methods: We retrospectively analyzed 219 consecutive SAA patients treated with IST from October 2008 to October 2015 and evaluated the haematological responses to IST. Results: The presence of a PNH clone was detected in 55 (25.1%) patients prior to IST [37/88 by flow cytometry (FCM) and 18/131 by fluorescent aerolysin (FLAER)] and 27 disappeared after IST (23/37 in initial FCM group, 4/18 in initial FLAER group, p = 0.005). In patients without an initial clone, 12 (30.0%) cases in FCM and 17 (19.5%) in FLAER groups presented a PNH clone at least once after IST (p < 0.001). In patients with a pre-treatment PNH clone detected by FCM, the 3-, 6- and 12-month response rates were higher than patients without (p = 0.006; 0.002 and 0.002, respectively). And in FLAER group, the 3-month response rate was significantly higher in those with a prior clone (p = 0.017), however, the 6- and 12-month response rates showed no differences (p = 0.105, p = 0.144, respectively). By multivariate analysis, a shorter interval between diagnosis and treatment is associated with a better response and survival. Conclusions: A more reliable FLAER method allows us to draw a conclusion that PNH clone predicts a faster response but not a higher response rate to IST. Once a diagnosis is confirmed, the IST should be initiated as soon as possible.

An interesting cause of severe anemia with acute kidney injury and enlarged kidneys

Abstract A 24-year-old female presented with jaundice for one month and oliguria for seven days. On general physical examination, she had pallor and icterus with rest of the systemic examination being normal. Her investigations showed pancytopenia with an elevated corrected reticulocyte count and mildly elevated indirect bilirubin levels. She also had deranged kidney function tests (KFTs) (blood urea – 125 mg/dl and serum creatinine – 6.4 mg/dl). Her Coomb's test (both direct and indirect) and other work up for causes of hemolytic anemia were negative. Her urine for hemoglobin was positive. In view of this, her Paroxysmal Nocturnal Hemoglobinuria (PNH) clone was tested which turned out to be positive. Her ultrasound showed bilaterally enlarged kidneys. With conservative management, her KFTs and blood picture gradually improved. An MRI done during the course of her illness was suggestive of hemosiderin pigment deposits in her kidneys, which were likely responsible for the acute renal injury and enlarged renal size.

Paroxysmal nocturnal haemoglobinuria. Experience over a 10 years period

Paroxysmal nocturnal hemoglobinuria (PNH) is a hemolytic, clonal and acquired disorder of the hematopoietic stem cell with a deficiency of all glycophosphatidyl-inositol (GPI) linked proteins. The aim of this retrospective study was to analyse haematological and biochemical data from 152 patients referred to our laboratory for diagnosis of PNH by flow cytometry (FC). Patients and healthy donor (152 and 99 respectively) were studied. Ham, sucrose, lactate dehydrogenase (LDH), Iron, haptoglobin (Hp), blood cell morphology and Kaplow cytochemical stain for leukocyte alkaline phosphatase (LAP) were carried out. GPI-proteins anti-CD55 and CD59 in erythrocytes and the former, plus anti CD16b and CD66b on neutrophils were evaluated by FC. Anemia and/or leukopenia and/or thrombocytopenia, increased reticulocyte count and LDH were observed in patients with PNH clone. Some of them had dacriocytes, schistocytes. LAP was low. On average, we detected 50% CD59 (-) erythrocytes and 29, 83, 78% CD55/59 (-), CD16b (-), CD66b (-) neutrophils, respectively. Paroxysmal nocturnal hemoglobinuria clone was detected in 20/152 patients. Negative population's percentages were high in patients with classic PNH, Hematimetry, LAP and adequate use of CF contribute to PNH clone detection in the laboratory.

Autologous recovery following non-myeloablative unrelated donor bone marrow transplantation for severe aplastic anaemia.

We report the outcome of nine unrelated bone marrow transplants performed for acquired severe aplastic anaemia at a single centre. Six patients received transplants from fully matched donors. Three donor/recipient pairs were mismatched, two at a single allele on high resolution typing. Pre-transplant conditioning consisted of cyclophosphamide and in vivo Campath-1 monoclonal antibody. One patient also received total body irradiation (TBI), and another patient with a coexisting paroxysmal nocturnal haemoglobinuria (PNH) clone received additional busulphan. Cyclosporin A was given for 12 months as prophylaxis against graft-versus-host disease (GVHD). Six of nine patients are alive and transfusion independent with a mean follow-up of 24 months (range: 1.5-94). All six patients who received fully matched transplants are alive; the three who received mismatched grafts died. Four long-term survivors developed autologous haematological recovery following rejection of their grafts. Acute GVHD grade II+ occurred in two patients. We highlight the importance of high-resolution HLA typing, including Cw matching in reducing the incidence of graft rejection and GVHD, resulting in improved survival in our patient group. This study also shows that autologous recovery with long-term survival can occur following non-irradiation conditioning regimens.

Screening for paroxysmal nocturnal hemoglobinuria (PNH) clone in Egyptian children with aplastic anemia.

Aplastic anemia and paroxysmal nocturnal hemoglobinuria (PNH) are clinically related. In addition to their concurrent or sequential appearance in individual patients, PNH and aplastic anemia share several pathophysiologic features. The aim of the present study was to screen for PNH clone in Egyptian aplastic anemia pediatric patients before the initiation of any specific therapy and to evaluate the clinical status of studied patients 3-6 months after initiation of immunosuppressive therapy. We studied 11 pediatric patients with newly diagnosed acquired aplastic anemia and followed them up clinically for 3-6 months after initiation of immunosuppressive therapy. In addition to routine clinical and laboratory evaluation, sucrose lysis test and staining of bone marrow for CD59 were performed in all subjects. All studies cases had severe aplastic anemia (SAA) except one case which had very severe aplastic anemia (VSAA). Sucrose lysis test was negative in all studied cases. Presence of PNH clone (as evident by loss of normal staining of hematopoietic cells for CD59 = CD59 negative cells) was evident in four subjects. All cases with PNH clone were >6 years old and one of them developed splenic vein thrombosis. As regards the laboratory data WBC < or = 2.8 x 10(3)/mm3 and reticulocytes > or = 0.6 per cent were the most frequent factors associated with PNH clone found in all PNH subjects, but only in 28.6 per cent and 14.3 per cent respectively, of non-PNH subjects. Mortality rate was higher in non-PNH subjects (28.5 per cent) compared to 25 per cent of PNH subjects. We conclude that immunohistochemical staining of bone marrow sections is a sensitive tool to detect the emergence of PNH clone in aplastic anemia patients. Thrombotic complications should be anticipated in cases with aplastic anemia having a PNH clone.

Expansion of a paroxysmal nocturnal hemoglobinuria (PNH) clone after cyclosporine therapy for aplastic anemia/PNH syndrome [letter; comment

Expansion of a paroxysmal nocturnal hemoglobinuria (PNH) clone after cyclosporine therapy for aplastic anemia/PNH syndrome [letter; comment