Screening for the carriers of thalassemias and abnormal hemoglobins at the community level.

Thalassemia and abnormal hemoglobins are common genetic disorders in Southeast Asia. Thalassemia is not only an important public health problem but also a socio-economic problem of many countries in the region. The approach to deal with the thalassemic problem is to prevent and control births of the new cases. This requires an accurate identification of couple at high risk to have a thalassemic child. The diagnosis of thalassemia carriers need several tests that are not practical for screening the population at large. In this study we used two simple laboratory tests to screen for potential thalassemia carriers and hemoglobin E individuals. Three-hundred pregnant women and 40 spouses were recruited in this study. The methods were the red cell osmotic fragility (OF) screening test with 0.36% NaCl and the dichlorophenolindophenol (DCIP) precipitation test to detect Hb E and unstable hemoglobins. Standard methods for red cell indices, hemoglobin analysis and detection of alpha-thalassemia by immunological method were also performed to confirm genotypes of thalassemia. The results showed that 98 women (32.7%) were carriers of thalassemias and hemoglobin E. The number of false positive by OF test was 3.2% and by DCIP test was 0.6%. Sensitivity and specificity of OF test were 89.5% and 93.3%, respectively whereas those of DCIP test were 100%. Of the 40 couples investigated, one was found to be at risk of having beta-thalassemia/Hb E fetus. Screening techniques including one tube osmotic fragility and DCIP precipitation tests are sensitive and specific for the detection of thalassemia and unstable hemoglobins such as Hb E. The techniques are also simple, economic, rapid, and give minimal false negative result.

Standardization on laboratory diagnosis of thalassemia and abnormal hemoglobin.

Thalassemia is one of the most common single gene disorders. The geographic distribution of thalassemia and abnormal hemoglobin has been known for many years. A worldwide significant spread of these abnormal genes, especially from Southeast Asia, occurred in the last two decades. This has resulted in a dramatic increase of Hb E disorders and various Southeast Asian thalassemia genotypes, which means that requests for hemoglobinopathy investigations are likely to increase in many laboratories worldwide. Hemoglobinopathy screening and diagnosis may need to be undertaken antenatally, neonatally and in certain hematological situations. The introduction of automation for hemoglobinopathy screening, including the automated cell counting and HPLC system, is an important advance in technology for hematology laboratories. The instruments need to be calibrated and standardized to get an accurate data for interpretation. Internal and external control samples are also needed. Combination of test results is usually required to achieve a proper diagnosis, which in turn, provide a self-check for each laboratory test.

Glomerulonephritis in beta-thalassemia Hb-E disease: clinical manifestations, histopathologic studies and outcome.

We presented 8 patients with beta-thal/Hb E with glomerular diseases. Diverse glomerular lesions were seen, but diffuse endocapillary glomerulonephritis was the most common. The clinical manifestations of acute glomerulonephritis in beta-thal/Hb E differed from typical cases in the older age group, female preponderance, longer duration of edema, less hypertension, marked proteinuria, hypoalbuminemia and hypertriglyceridemia and also a longer period of recovery but their outcome was still favorable despite many risk factors of renal injury. Renal biopsy was necessary in doubtful cases to detect the correct diagnosis and give proper management. The association and mechanism of glomerulonephritis in these patients require further prospective study.

Significance of blood coagulation and platelet profiles in relation to pulmonary thrombosis in beta-thalassemia/Hb E.

In beta-Thalassemia hemoglobin E (beta-thal Hb E), hypoxemia with abnormal lung function was described and postmortem examination in these patients showed organized pulmonary trombi with thickened arterial wall, particularly in post-splenectomized cases. Coagulation and platelet profiles were studied in 58 beta-thal Hb E patients. In 35 cases with intact spleen, the fibrinolytic activity was significantly decreased with high antithrombin III activity, while coagulation tests revealed mild abnormality. The platelet aggregation to ADP, adrenaline, collagen and ristocretin were defective and platelet 5-hydroxytryptamine content was lower than normal. Twenty-three patients who had been splenectomized for 5-18 years, decreased fibrinolytic activity and high antithrombin III activity were also observed. The coagulation profiles and platelet aggregation in response to ADP, adrenaline and collagen showed better results. Fourteen cases exhibited thrombocytosis and their thrombin generation was in the hypercoagulable range. Platelet aggregation in response to ristocetin remained defective and platelet 5-hydroxytryptamine content was lower than in cases with intact spleens. Defective aggregation to ristocetin would indicate abnormal von Willebrand's factor (vWF). Decreased fibrinolysis should very likely have a role in the occurrence of thrombosis and the better hemostatic profiles in post-splenectomized cases would contribute to the more frequent thrombotic incidence in these cases.

Outcomes of pregnancy in adult idiopathic thrombocytopenic purpura.

The outcomes of 39 pregnancies in 36 idiopathic thrombocytopenic purpura (ITP) patients were analysed. Among the 36 pregnant patients, 23 had active ITP (platelet count < 100,000 per mm3), 12 had inactive ITP, during pregnancies, while one patient had active and inactive ITP during each of her two pregnancies. Maternal bleeding during delivery occurred more commonly in thrombocytopenic patients and was more frequent by cesarean section than by vaginal delivery. There was a 56 per cent incidence of neonatal thrombocytopenia. Maternal platelet count had no predictive value for neonatal thrombocytopenia. There was no serious bleeding among neonates born from thrombocytopenic mothers. In our experience, vaginal delivery was a relatively safe procedure for delivering small neonates from multiparous ITP mothers. Cesarean section should be used to deliver relatively big neonates especially from primigravida ITP mothers and splenectomy should be done at the same time.

Hypoxemia in thalassemia.

Data are reviewed describing hypoxemia, a newly identified feature in thalassemia. Evidence indicates platelet aggregation in the pulmonary circulation as being a key factor leading to hypoxemia and cor-pulmonale with right heart failure.

High-dose intravenous immunoglobulin in the management of immune hemolysis in patients with thalassemic disease: factors which determine refractoriness.

We report our experience with high dose intravenous immunoglobulin (IVIg) in 3 thalassemic patients who had evidence of possible immune hemolysis. In 2 patients who had serious sepsis, their responses to IVIg were only partial and transient. The other patient who had marked splenomegaly had no evidence of response to IVIg. Both serious infections and large spleen may hamper the effect of IVIg and should be considered before IVIg is to be used in thalassemia.

Cytochemical stainings in acute promyelocytic leukemia: chloroacetate esterase reaction as a prognostic index.

Cytochemical studies including peroxidase, sudan black B and esterases were used for staining peripheral blood and bone marrow smears from 42 patients with acute promyelocytic leukemia. The most sensitive methods were sudan black B (mean 98%, range 81-100%) and peroxidase (mean 92% range 70-100%). Naphthol AS-D chloroacetate esterase activity was less sensitive and was positive in only 49.4 per cent (range 2-100%). All of the population of leukemic cells contained less than 3 per cent of alpha-naphthyl acetate esterase staining. For stability tests of the storage specimens compared to fresh stains, there was no difference in naphthol AS-D chloroacetate esterase (mean 45% vs 49% P greater than 0.7) and sudan black B (mean 74% vs 98% P greater than 0.3), but the enzyme activity was significantly decreased in peroxidase staining (mean 42% vs 92% P greater than 0.05). When the patients were divided into 2 groups according to the degree of AS-D chloroacetate esterase activity, those with lower activity had a higher number of white blood cells, promyelocytes and shorter survival compared to those with higher activity. Therefore, naphthol AS-D chloroacetate esterase may be useful as a prognostic index.

Severe hyperbilirubinemia in glucose-6-phosphate dehydrogenase deficient patients during viral hepatitis.

Nine G-6-PD subjects developed acute hemolysis and severe hyperbilirubinemia (up to 61.1 mg/dl) following viral hepatitis. All except one had fever at presentation. Neutrophilic leukocytosis was a common feature. Elevation of both alanine aminotransferase (SGPT) and extremely high level of aspartate aminotransferase (SGOT) were prominent. Three developed acute renal failure. All patients survived, one after peritoneal dialysis. Recognition of the clinical picture is essential to prevent serious complications and for successful management.

Abnormalities of hematopoietic progenitor cells in patients with aplastic anemia after hematologic recovery.

Hematopoietic progenitor cells were studied in 11 patients with aplastic anemia who had hematologic recovery after androgen therapy. The mean numbers of colonies derived from erythroid and granulocyte-macrophage progenitor cells (BFU-E and CFU-GM) were markedly decreased compared to normal controls. Cell-mediated suppression of colony growth as detected by coculture studies was observed in 5 patients; 4 patients for CFU-GM and one for both CFU-GM and BFU-E. It is thus concluded that the pool of hematopoietic stem cells in patients after hematologic recovery is still not fully reconstituted. In addition, this impaired reconstitution appears due in some cases to cell mediated suppression of progenitor colony growth.

Studies on the pathogenesis of aplastic anemia in Thailand: evidence of immune-mediated mechanism.

The pathogenesis of aplastic anemia in Thailand was studied by using in vitro progenitor cells culture. In 37 patients who had active disease, the numbers of colonies derived from erythroid and granulocyte-macrophage progenitor cells (BFU-E and CFU-GM) were markedly decreased both in the blood and bone marrow as compared to normal controls. Co-culture of patients' cells with normal blood cells was performed in order to verify an immunologically mediated mechanism. In 8 of 26 patients, there were very low numbers of colonies both BFU-E and CFU-GM in the blood and bone marrow with significant suppression of colony formation in co-culture. Suppressor cells may have caused the aplasia in these patients. The rest had low colony formation and no suppression in co-culture. These patients may have absent or defective stem cells. None had normal colony formation. Therefore, aplastic anemia in Thailand may result mostly from defects involving the stem cells. Only some patients had cell mediated suppression of hematopoiesis as detected by co-culture.

Methylprednisolone treatment in aplastic anaemia.

Twenty patients with aplastic anaemia were treated with a short term bolus of methylprednisolone. Seven patients were refractory to anabolic steroids and were observed in very long follow-up periods of 14-104 months. Thirteen patients had never been treated. The latter group also received anabolic steroids. Five out of 20 patients responded to the treatment while the remaining patients did not or died. Responders among patients refractory to anabolic steroids had shorter duration of disease compared to non-responders. No recurrence of aplasia was observed in all responders.

Identification of different types of lymphoblasts in patients with acute lymphoblastic leukemia.

Identification of different types of lymphoblasts in acute lymphoblastic leukemia were studied with light microscopy, SEM and TEM.