To analyze the clinical characteristics and risk factors on responses and survival of myelodysplastic syndromes (MDS) patients with paroxysmal nocturnal hemoglobinuria (PNH) clones.The clinical data of 31 MDS cases with PNH clones from October 2004 to June 2012 were retrospectively analyzed to reveal the influence of PNH clone size on responses and survival.①The chromosome karyotypes were analyzed in all patients, 23 patients with normal karyotype, 7 patients with abnormal karyotype [including 3 patients with +8, 2 -Y, 1 del(7q) and 1 Xp+] and 1 patient with no mitosis. 1 patient belonged to low-risk, 27 intermediate-1 risk, 2 intermediate-2 risk and 1 high-risk groups, respectively, according to IPSS. There were significantly statistical differences between responders and nonresponders in terms of infection, ANC, Reticulocyte count and IPSS (P values were 0.049, 0.006, 0.031 and 0.043, respectively). ②The overall responsive rate was 67.7%, no patients progressed to acute leukemia (AL) during median follow-up of 19 months after immunosuppressive therapy (IST). The 3-year and 5-year overall survival rates were 82.7% and 55.1%,respectively. ③According to univariate analysis,age, infection and ANC had significant influence on survival (P values were 0.050, 0.031 and 0.026, respectively). ④The PNH clone size had no significant influence on survival through univariate and COX analyses (P=0.393).MDS patients with PNH clone had less cytogenetic abnormalities, higher probability of response to IST and lower probability of progression to AL; Furthermore, the PNH clone size had no significant influence on response and survival.

Hematopoietic stem cell transplantation (HSCT) is a new window to therapy of many diseases. From March 1991 through April 2011, a total of 3237 HSCT were performed in the Hematology-Oncology and Stem Cell Transplantation Research Center, affiliated to Tehran University of Medical Sciences. Here we report 20 years experience of HSCT.Our strategy and aim include the protraction of cytogenetic and molecular biological diagnostic tests, the expansion of the first Iranian Cord Blood Bank (ICBB) and development of the first Iranian Stem Cell Donor Program (ISCDP), and improvement the researches in new therapeutic fields.Totally, 3237 patients were undergone HSCT. Of these transplants, 2205 were allogeneic stem cell transplantation, 1016 autologous and 16 syngeneic. Among 2205 patients who were undergone allogenic-HSCT, 34 received cord blood stem cells as stem cell source for transplantation. It is important to point out that cord blood bank at our center provides reliable storage of cord blood stem cells for our patients. Stem cell transplantation was performed for treatment of various diseases such as acute myelogenous leukemia, acute lymphoblastic leukemia, chronic myelogenous leukemia, chronic lymphoblastic leukemia, beta-thalassemia major, sickle- cell thalassemia, sickle- cell disease, multiple myeloma, myelodysplasia, mucopolysaccharidosis, paroxysmal nocturnal hemoglobinuria, non-Hodgkin's lymphoma, Hodgkin's disease, severe aplastic anemia, plasma cell leukemia, Niemann-Pick disease, Fanconi anemia, severe combined immunodeficiency, congenital neutropenia, leukocyte adhesion deficiencies, Chediak-Higashi syndrome, osteopetrosis, histiocytosis X, Hurler syndrome, amyloidosis, systemic sclerosis, breast cancer, Ewing's sarcoma, testicular cancer, germ cell tumors, neuroblastoma, medulloblastoma, renal cell carcinoma, nasopharyngeal carcinoma, ovarian cancer, Wilms' tumor, rhabdomyosarcoma, pancreatoblastoma, and multiple sclerosis. Also, we had 220 cellular therapies for post-myocardial infarction, multiple sclerosis, cirrhosis, head of femur necrosis, Diabetes Mellitus and GvHD treatment. 45 patients were undergone retransplantation in this center.About 78.2% of the patients (2530 of 3237) remained alive between one to 211 months after stem cell transplantation. Nearly, 21.8% (707) of our patients died after stem cell transplantation. The main causes of death were relapse, infection, hemorrhagic cystitis, graft-versus- host disease and etc.In Iran, HSCT has been successfully adapted in routine clinical care. Recently, new methods such as double cord blood and haploidentical transplantation have been used to treat many life-threatening diseases.

Drug-induced immune hemolytic anemia (DIIHA) is a relatively uncommon condition characterized by a sudden drop in hemoglobin, putatively following exposure to drugs. Severe forms of hemolysis characterized by rapidly falling hemoglobin levels and hemoglobinuria are extremely rare. Here we report the case of a patient who exhibited severe DIIHA due to puerarin. Direct antiglobulin testing and drug-dependent antibody testing indicated that the antibodies were drug-dependent and reacted only with RBCs in the presence of the drug. Puerarin is the major isoflavonoid derived from the Chinese medical herb Radix puerariae, and has not yet been widely reported as associated with DIIHA. These results suggest that puerarin may be a cause of severe hemolysis and should be used with caution.

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by chronic, complement-mediated hemolysis, frequently leading to debilitating clinical symptoms and life-threatening complications such as thromboembolism (TE). A retrospective analysis was performed on 301 patients from the South Korean National PNH Registry to describe disease burden and identify TE-associated risk factors. TE was identified in 18 % of patients and was associated with increased risk for mortality [odds ratio (OR), 6.85; P < 0.001]. A multivariate analysis showed that PNH patients with elevated hemolysis [lactate dehydrogenase (LDH) levels ≥1.5 times the upper limit of normal (ULN)] at diagnosis were at significantly higher risk for TE than patients with LDH <1.5 × ULN (OR 7.0; P = 0.013). The combination of LDH ≥1.5 × ULN with the clinical symptoms of abdominal pain, chest pain, dyspnea, or hemoglobinuria was associated with a greater increased risk for TE than elevated hemolysis or clinical symptoms alone. Continuous monitoring of these risk factors is critical for identifying PNH patients at risk for morbidities and mortality and allowing early intervention. (clinicaltrials.gov identifier: NCT01224483).

The most frequent and feared complication of paroxysmal nocturnal hemoglobinuria (PNH) is thrombosis. Recent research has demonstrated that the complement and coagulation systems are closely integrated with each influencing the activity of the other to the extent that thrombin itself has recently been shown to activate the alternative pathway of complement. This may explain some of the complexity of the thrombosis in PNH. In this review the recent changes in our understanding of the pathophysiology of thrombosis in PNH as well as the treatment of thrombosis will be discussed. Mechanisms explored include platelet activation, toxicity of free hemoglobin, nitric oxide depletion, absence of other GPI-linked proteins such as urokinase-type plasminogen activator receptor and endothelial dysfunction. Complement inhibition with eculizumab generally has a dramatic effect in PNH and has a major impact in the prevention of thrombosis as well as its management in this disease.

Paroxysmal nocturnal hemoglobinuria (PNH) is a rare, acquired disorder characterized by chronic intravascular hemolysis as the primary clinical manifestation and morbidities that include anemia, thrombosis, renal impairment, pulmonary hypertension, and bone marrow failure. The prevalence of the PNH clone (from <1-100% PNH granulocytes) is approximately 16 per million, and careful monitoring is required. The average age of onset of the clinical disease is the early 30s, although it can present at all ages. PNH is caused by the acquisition of a somatic mutation of the gene phosphatidylinositol glycan anchor (PIG-A) in a multipotent hematopoietic stem cell (HSC), with clonal expansion of the mutated HSC. The mutation causes a deficiency in the synthesis of glycosylphosphatidylinositol (GPI). In cells derived from normal HSCs, the complement regulatory proteins CD55 and CD59 are anchored to the hematopoietic cell membrane surface via GPI, protecting the cells from complement-mediated lysis. However, in patients with PNH, these 2 proteins, along with numerous other GPI-linked proteins, are absent from the cell surface of red cells, granulocytes, monocytes, and platelets, resulting in complement-mediated intravascular hemolysis and other complications. Lysis of red blood cells is the most obvious manifestation, but as other cell lineages are also affected, this complement-mediated attack contributes to additional complications, such as thrombosis. Eculizumab, a humanized monoclonal antibody against the C5 complement protein, is the only effective drug therapy for PNH patients. The antibody prevents cleavage of the C5 protein by C5 convertase, in turn preventing generation of C5b-9 and release of C5a, thereby protecting from hemolysis of cells lacking the CD59 surface protein and other complications associated with complement activation. Drs. Ilene C. Weitz, Anita Hill, and Jeff Szer discuss 3 recent cases of patients with PNH.

Nitric oxide is a potent vasodilator that plays a critical role in disorders of erythrocyte function. Sickle cell disease, paroxysmal nocturnal hemoglobinuria and banked blood preservation are three conditions where nitric oxide is intimately related to dysfunctional erythrocytes. These conditions are accompanied by hemolysis, thrombosis and vasoocclusion. Our understanding of the interaction between nitric oxide, hemoglobin, and the vasculature is constantly evolving, and by defining this role we can better direct trials aimed at improving the treatments of disorders of erythrocyte function. Here we briefly discuss nitric oxide's interaction with hemoglobin through the hypothesis regarding Snitrosohemoglobin, deoxyhemoglobin, and myoglobin as nitrite reductases. We then review the current understanding of the role of nitric oxide in sickle cell disease, paroxysmal nocturnal hemoglobinuria, and banked blood, and discuss therapeutics in development to target nitric oxide in the treatment of some of these disorders.

Acinetobacter infections are fast emerging as a major nosocomial threat across the globe. With a predilection for blood stream infections in critically ill, immunocompromised patients, their presence is now being felt in febrile neutropenics with underlying malignancies and marrow failure. We aimed through this study to ascertain the current circulating pathogens and levels of antimicrobial resistance in blood stream infections in febrile neutropenia patients, with specific emphasis on elucidating acinetobacter and pseudomonas infections. Clinical and laboratory records of all consecutive neutropenic patients with underlying haematological malignancies and marrow failure, admitted to our AIIMS, New Delhi from April 2009 to March 2010 were analysed for blood stream infections, pathogen profiles and antimicrobial resistance. All clinical and microbiological variables were statistically analysed to elucidate potential risk factors, infection patterns and drug resistance trends. Of the 1,165 blood cultures investigated, 105 episodes of blood stream infections were microbiologically confirmed in febrile neutropenia patients. Gram-negative infections (n = 78, 72.9%) dominated with acinetobacter spp (n = 20, 18.7%) emerging as the most common pathogen. Acinetobacter and pseudomonas together were responsible for 42.9% of all blood stream infections. Both acinetobacter and pseudomonas displayed very high resistance to all five major classes of antibiotics, including multidrug resistance (90.0% and 76.9%) and ESBL production (90.0% and 84.6%), respectively. Comparison of infection patterns and resistance levels with reports over the past decade from this centre and other centres across the globe, revealed a striking increase in multidrug resistant acinetobacter blood stream infections in these patients. Multidrug resistant acinetobacter Infections are a fast emerging threat in febrile neutropenia patients and at this centre in general. Similar early trends from some Indian centres and neighbouring developing countries suggest grave concern. These emerging circulating pathogens and drug resistance patterns demand to systematically evaluate antibiotic and hospital infection policies and to sensitise all clinicians to curb this pathogen capable of rapid nosocomial spread.

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired stem cell disorder characterized by intravascular hemolysis and thrombosis. The most serious complication is thrombosis, the risk of which is augmented by the hyper-coagulable state that occurs during pregnancy; despite this risk, however, young female PNH patients often desire to have a baby. We recently experienced two successful deliveries in PNH patients, who were treated with anticoagulant therapy during their pregnancies. Meanwhile, given the potential benefit of eculizumab (Soliris), a humanized monoclonal antibody against C5, in reducing thrombosis and hemolysis, it represents a promising therapeutic option for the treatment of pregnant PNH patients in combination with, or in replacement of, anticoagulant therapy.