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Biomedical subjects

N Win

Publications and source records attributed to N Win.

At least 19 recordsLinked to original sources
PubMed2005

Severe gestational (incidental) thrombocytopenia: to treat or not to treat.

Thrombocytopenia is common in pregnancy and is diverse in etiology. Immune thrombocytopenic purpura (ITP) may affect both mother and the newborn. Gestational (incidental) thrombocytopenia in an otherwise fit woman, at term is the most frequent type of thrombocytopenia and poses no clinical consequences for mother or infant. We report six women who presented with severe thrombocytopenia during pregnancy. Five were treated in late pregnancy, either with intravenous immunoglobulin (IVIg), or IVIg followed by steroids. There was no response, and four received a platelet transfusion during delivery. The platelet counts in all the infants were normal and the maternal thrombocytopenia resolved spontaneously after delivery in all cases. Our observations suggest that this is a group of patients with a severe form of gestational thrombocytopenia. The severe form of gestational thrombocytopenia appears to be rare, and recognition is important, as it may recur in subsequent pregnancies and does not require any therapeutic intervention.

Adult↗
PubMed2005

Intravenous immunoglobulin given to lymphoma patients with recurrent haemolytic transfusion reactions after transfusion of compatible blood.

Accelerated destruction of red cells after transfusion of compatible blood has been reported in both sickle cell disease (SCD) and non-SCD patients. We report three patients with lymphoma, all of whom had recurrent haemolytic transfusion reactions after receiving compatible red cell units. The direct antiglobulin test (DAT) was negative and there were no detectable red cell alloantibodies in either pre-transfusion or post-transfusion samples. As there was no evidence of red cell antibody-mediated haemolysis and response to oral steroids, a trial of intravenous immunoglobulin (IVIg) was given. Immediate cessation of haemolysis with sustained haemoglobin level was achieved in all cases. The response to IVIg in these cases suggests that IVIg should be tried when recurrent non-antibody mediated haemolytic transfusion reactions occur in patients with a lymphoid malignancy.

Aged↗
PubMed2005

Use of red cells preserved in extended storage media for exchange transfusion in anti-k haemolytic disease of the newborn.

Anti-k is a Kell-related antibody. There is little correlation between the maternal antibody titre and the severity of haemolytic disease of the foetus and newborn, and anaemia is usually associated with low bilirubin levels. Severe erythroblastosis has been reported with a low titre anti-k (IAT 8-16). We report a case of severe haemolytic disease of the newborn (HDN) due to anti-k. HDN was associated with a normal bilirubin level and reticulocytopenia. The foetus was monitored by ultrasound, and delivery by elective caesarean section (CS) was planned. The mother was admitted 1 week before the expected date of delivery, and the infant was delivered by urgent CS. The infant required exchange transfusion. As suitable plasma-reduced (k antigen(-)) red cell units were not readily available, k- SAGM red cell units (preserved in extended storage media: SAGM sodium chloride, adenine, glucose and mannitol) were provided. The post-transfusion Hb remained stable, and the infant did not require further transfusion support. Our findings (reticulocytopenia and normal bilirubin levels) support the hypothesis that the pathogenesis of anaemia and haemolysis in anti-k HDN may be similar to that in anti-K (suppression of erythropoesis and immune destruction of K+ erythroid progenitor cells by macrophages in the foetal liver). The ideal product for exchange transfusion is plasma-reduced RBC, less than 5-days old. We provided a 4-day-old SAGM red cell unit for exchange transfusion in a term infant, and this was uneventful. Caution should be taken, however, and renal function and electrolyte levels should be monitored closely. More information is required regarding the safety of SAGM units for exchange transfusion.

Adult↗
PubMed2005

Autoimmune hemolytic anemia and a further example of autoanti-Kpb.

A 65-year-old Caucasian man with myelodysplasia was admitted with autoimmune hemolytic anemia and a Hb of 5.6 g/dL. The patient's serum contained anti-K; the DAT on the patient's RBCs reacted 3+ with anti-IgG and 3+ with anti-C3d. K- RBC units were transfused, but there was no sustained increase in Hb level. The samples were referred to the reference laboratory of the National Blood Service. The DAT results remained the same, with anti-K detected only in the serum. An eluate prepared from the patient's DAT-positive RBCs revealed anti-Kp(b) specificity. This study reports an unusual case of autoanti-Kp(b), which is different from previously published cases in that no free anti-Kp(b) was detectable in the serum.

Aged↗
PubMed2001

Platelet apheresis for digital gangrene due to thrombocytosis in chronic myeloid leukaemia.

Thrombocytosis is a frequent presenting feature of myeloproliferate disorders and is associated with increased incidence of thrombotic and haemorrhage complications. However, these complications are rare in chronic myeloid leukaemia (CML). We describe a case of CML which presented with digital gangrene due to thrombocytosis. Reduction of the platelet count by plateletpheresis lead to rapid symptomatic relief and recovery from the gangrene.

Adult↗
PubMed2001

Hyperhemolytic transfusion reaction in sickle cell disease.

BACKGROUND: An atypical form of life-threatening hemolytic transfusion reaction (HTR) in patients with sickle cell disease (SCD) has been well described in the literature. Continuation of blood transfusion may be lethal, as it can further exacerbate hemolysis. The pathophysiologic mechanism of HTR is not well understood. CASE REPORTS: Two cases of severe HTR in SCD after the transfusion of compatible RBC units are reported. Hemolysis of both autologous and transfused cells was documented in Case 1 by urine Hb high-performance liquid chromotography. Multispecific HLA antibodies were identified in Case 1. Reticulocytopenia was noted in both cases during the acute hemolytic process. This was followed by a rise in reticulocyte count during receipt of IVIG and steroid therapy. Bone marrow examination during reticulocytopenia in Case 2 showed erythroid hyperplasia. CONCLUSION: In SCD, both mature sickle cells and sickle reticulocytes adhere more readily to macrophages. In view of the bone marrow aspiration results, it appears that the recipients' HbS cells are destroyed by hyperactive macrophages and that the reticulocytopenia observed during HTR is likely to be due to peripheral consumption (i.e., destruction by macrophages), rather than suppression of erythropoiesis. Cessation of hemolysis during IVIG and steroid treatment may be due to IVIG's blocking of the adhesion of sickle cells and reticulocytes to macrophages, together with steroid suppression of macrophage activity.

Adult↗
PubMed2001

Recurrent transfusion-related acute lung injury.

BACKGROUND: Transfusion-related acute lung injury (TRALI) is a rare condition that is commonly associated with the transfusion of donor plasma containing WBC antibodies. Biologically active lipids that accumulate during storage of RBCs and platelets may also cause TRALI. There has been only one previously reported case of recurrent TRALI. CASE REPORT: A patient received a transfusion 2 days after undergoing hysterectomy; she developed TRALI after receiving the transfusion. The patient recovered after being on ventilation for 6 days but received an additional transfusion and had a second episode of TRALI, which required further ventilation. RESULTS: Laboratory investigation of the first episode of TRALI suggested the presence of HLA-A2 (N = 1) and granulocyte-specific IgM antibodies (N = 2) in the sera from three of the donors. All three sera reacted in crossmatch studies with the patient's granulocytes and lymphocytes. Lymphocyte-specific IgG antibodies were detected in the patient's serum. There was no evidence to suggest the involvement of WBC antibodies in the second episode of TRALI. Antibody screening of the donors' samples and both forward and reverse crossmatch studies were negative. CONCLUSION: The first episode of TRALI seems to be due to the action of HLA-A2 and granulocyte-specific IgM antibodies. The second episode may have been due to the action of lipid neutrophil-priming agents in the donors' units in association with the patient's underlying pulmonary condition (i.e., recovering from lung injury). TRALI can recur if a patient requires further transfusion support shortly after an initial episode of TRALI.

Acute Disease↗
PubMed2000

Transfusion-related acute lung injury associated with interdonor incompatibility for the neutrophil-specific antigen HNA-1a.

BACKGROUND AND OBJECTIVES: A patient transfused with two pooled platelet concentrates became breathless. Bilateral infiltrates were seen on chest X-ray. A diagnosis of transfusion-related acute lung injury (TRALI) was made. The patient received 100% oxygen and recovered after 5 days. MATERIALS AND METHODS: Antibody screening, cross-matching for granulocyte and lymphocyte antibodies and typing for granulocyte antigens was undertaken. RESULTS: The patient typed as HNA-1b/HNA-1b. Granulocyte and lymphocyte antibodies were not detected in the patient's serum or in any of the donor sera by cross-match. In antibody screening against typed panel granulocytes, complement-fixing anti-HNA-1a IgM antibodies were detected in the serum of one female donor. Two of the other donors who contributed to the pooled platelet concentrate containing the HNA-1a IgM antibodies typed as HNA-1a/HNA-1b. CONCLUSION: Anti-HNA-1a IgM antibodies may have formed immune complexes with white cell fragments or soluble FcgammaRIII from HNA-1a+ donors in the pooled platelet concentrate and initiated TRALI.

Adult↗
PubMed2000

High prevalence of hepatitis C in patients with thalassemia and patients with liver diseases in Myanmar (Burma).

We conducted Myanmar-Japan cooperation studies on hepatitis B and hepatitis C virus markers in patients with thalassemias and those with liver diseases. Among the 102 patients with liver diseases, 92% had a history of hepatitis B virus infection (antibody to hepatitis B core antigen positive), 35% were hepatitis B surface antigen positive, 39% were positive for anti-HCV. Among 28 patients with hepatocellular carcinoma, 46% had hepatitis B surface antigen, 21.4% had antibody to hepatitis C virus, and 7% were positive for both hepatitis B surface antigen and anti hepatitis C virus. The history of HCV infection among blood recipients at the Haematology Department of the Yangon General Hospital and at the Yangon Children's Hospital was found to be 55.5% and 46.7%, respectively, which is comparable to the history of hepatitis B infection (66.7% and 46.7%, respectively). This preliminary survey also encountered 2 cases positive for anti-HCV among 34 voluntary blood donors. This survey is the first one to report that hepatitis C is at the epidemic stage in Myanmar. As there is no effective treatment for hepatitis C in this country, a screening program for blood used in transfusion should be started immediately.

Adult↗
PubMed1998

Anti-U and haemolytic disease of the fetus and newborn.

The red cell alloantibody, anti-U, is uncommon but is a recognised cause of haemolytic disease of the fetus and newborn. We describe six pregnancies complicated by the presence of maternal anti-U, and review nine other well-documented cases. In these 15 cases severe haemolytic disease occurred only with titres of > or = 1/512, and titres as high as 1/4000 were not necessarily associated with significant haemolysis. We recommend that an anti-U titre of > or = 1/128 or more at > or = 17 weeks of gestation is an indication for assessment of haemolysis in the fetus. Amniocentesis is the preferred initial investigation.

Amniocentesis↗
PubMed1998

Rapid cardiovascular action of aldosterone in man.

Rapid nongenomic in vitro effects of aldosterone have been demonstrated recently in cultured vascular smooth muscle and endothelial cells. But there is, as yet, little evidence for corresponding in vivo effects. The present study thus investigates the rapid nongenomic effects of aldosterone on human cardiovascular function. In a double-blind placebo-controlled randomized parallel trial on 17 patients with suspected coronary heart disease, the effect of 1 mg aldosterone iv on cardiovascular function was assessed during cardiac catheterization. Hemodynamic parameters (such as heart rate, left ventricular and atrial pressures, arterial pressures, vascular resistances, and cardiac output) were measured before and 3 and 10 min after administration of aldosterone or placebo. Significant changes were found for systemic vascular resistance, cardiac output, and cardiac index, compared with the placebo group (Wilcoxon test, P < 0.02-0.05). The effect of aldosterone dissipated within 10 min. The results are in line with the in vitro data cited above and consistent with earlier findings on acute cardiovascular effects of aldosterone, which have now been confirmed and extended by contemporary techniques. The hypotheses of rapid nongenomic in vivo effects of aldosterone are further substantiated by this study.

Aldosterone↗
PubMed1997

Pilot study of HLA alloimmunization after transfusion with pre-storage leucodepleted blood products in aplastic anaemia.

We have performed a pilot study to examine the incidence of alloimmunization using pre-storage leucocyte-depleted blood products (PLDP) in 16 previously transfused aplastic anaemia (AA) patients with no detectable HLA antibodies. A further eight AA patients with HLA antibodies received HLA-matched PLDP. Leucodepleted apheresed platelets were obtained using either Cobe spectra or Haemonetics system with an integral pall filter. Pall BPF4 filters were used for red cell preparation. Patients' sera were tested for HLA antibodies using lymphocytotoxicity (LCT). Patients who were HLA antibody negative by LCT at study entry were further tested with enzyme-linked immunoassay (ELISA). Out of 16 patients, two (12%) formed anti-HLA antibodies with a median follow-up of 9 months (range 1-15), but did not display platelet refractoriness to random donor platelets. Two patients were inadvertently transfused with non-leucodepleted blood products when later referred back to their local hospital. Both subsequently demonstrated HLA antibodies by LCT and became platelet refractory. These results contrast with a 50% incidence of HLA alloimmunization in a control group of AA patients transfused prior to this study with non-PLDP. HLA antibodies could no longer be detected by LCT in follow-up of three out of eight patients with HLA antibodies at study entry. Only one patient experienced non-haemolytic febrile transfusion reactions (NHFTR). We conclude that PLDP reduce the risk of alloimmunization even in previously transfused AA patients, PLDP are associated with a low incidence of NHFTR, and all new AA patients should receive PLDP from diagnosis.

Adolescent↗
PubMed1997

Positive direct antiglobulin test due to antiphospholipid antibodies in normal healthy blood donors.

OBJECTIVES: Positive direct antiglobulin tests (DAT) occur occasionally, without obvious cause, among normal blood donors. This is sometimes associated with a false-positive serologic test for syphilis. Positive DATs due to antiphospholipid antibodies (APAbs) are well documented in the antiphospholipid syndrome with systemic lupus erythematosus and the primary antiphospholipid syndrome. METHODS: Using conventional haematologic and serologic methods, we tested 474,545 normal blood donors in the west of Scotland during the years 1991 through 1993. RESULTS: We identified 42 normal blood donors with a positive DAT and observed three who had positive DATs and false-positive VDRL tests, all of whom expressed raised APAbs. CONCLUSION: APAbs may be an incidental cause of positive DATs among healthy blood donors.

Antibodies, Antiphospholipid↗