Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0039730 (thalassemia)
 10,305 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

T-cell-mediated inhibition of granulomonopoietic progenitors (CFU-GM) was studied in vitro in 27 patients with severe aplastic anaemia (AA). In nine out of 13 responders to anti-thymocyte globulin (ATG), cultured T-cells obtained prior to therapy, as well as their conditioned medium strongly suppressed both normal allogeneic and autologous CFU-GM (the latter obtained after marrow recovery). Addition of anti-interferon-gamma to the cultures abolished the suppressive effect on CFU-GM. After ATG therapy, no similar inhibitory effect was detected. Employing the panning method with monoclonal antibodies (CD4+ for inducer/helper and CD8+ for cytotoxic/suppressor T-cells) we were able to show that the cells responsible for in vitro CFU-GM inhibition were included in the cytotoxic/suppressor T-cell subpopulation. Cultured T-cells and their conditioned medium obtained from 14 non-responders to ATG did not show CFU-GM suppression. The mean interferon (IFN) levels in the T-cell conditioned media of ATG-responders was 625 +/- 125 mu/ml while in non-responders the level was 45 +/- 15 mu/ml (normal control levels 43 +/- 24 mu/ml). Freshly isolated peripheral blood lymphocytes from either group did not show any in vitro inhibitory effect. The response rate to ATG was statistically significant when the generation in culture of high versus low IFN production was compared (P = 0.0001). Experiments with T-cells obtained from heavily transfused thalassaemia major, and myelodysplastic syndrome patients, as well as normal volunteers, also did not demonstrate any suppression of CFU-GM. Our results indicate that the response rate to ATG is significantly higher in patients with AA who have an abnormal regulation of interferon-gamma (g-IFN) production.
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PMID:In vitro interferon-gamma production by cultured T-cells in severe aplastic anaemia: correlation with granulomonopoietic inhibition in patients who respond to anti-thymocyte globulin. 313 95

We previously observed that natural killer (NK) activity toward K562 cells is markedly depressed in patients with beta-thalassaemia major. Here we report that these patients also exhibit significantly decreased (P less than 0.005) NK cytotoxicity against human fibroblasts infected with herpes simplex virus-type 1 (HSV-1) and that the amount of alpha-interferon (alpha-IFN) generated during the latter assays is significantly less than normal (P less than 0.005). This decreased production of alpha-IFN may account in part for the decreased NK activity seen in the thalassaemia patients. On the other hand, the cytotoxicity of their mononuclear cells (MNC) toward both K562 cells and HSV-1-infected fibroblasts could be augmented to the same extent as that of normal MNC by preincubation with alpha-IFN suggesting that thalassaemia MNC are capable of responding to this lymphokine despite their reduced ability to produce it. Moreover, preincubation of thalassaemia MNC with desferrioxamine (DFO), an iron-chelating agent, consistently increased the lysis of K562 cells indicating that the transfusion-induced iron overload which these patients experience may also contribute to the defective NK function seen in this disease. We have now found that preincubation of such MNC with DFO has no effect upon production of alpha-IFN when the MNC are cocultured with either HSV-1-infected fibroblasts or K562 cells. Combining DFO and alpha-IFN resulted in an increase in the NK activity of both normal and thalassaemia MNC against the two targets which was greater than that with alpha-IFN alone. In fact, preincubation of thalassaemia cells with this combination increased their NK activity toward K562 targets to that of untreated normal cells. This was true when either unfractionated MNC or NK-enriched fractions were used as effector cells. These results suggest that DFO and alpha-IFN enhance NK activity by different mechanisms, both of which appear to be reversibly impaired in thalassaemia patients.
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PMID:Modulation of the defective natural killer activity seen in thalassaemia major with desferrioxamine and alpha-interferon. 342 26

The suppressive effect of two types of human interferon (fibroblast and leukocyte types) on bone marrow and peripheral blood erythroid colony formation by cells from patients with various disorders of erythropoiesis was studied. Bone marrow or peripheral blood mononuclear cells were isolated and cultured in plasma clots with Epo, and benzidine-positive erythroid colonies counted after 7 to 14 days' incubation. Specimens included cells from patients with thalassemia, sickle cell anemia, secondary polycythemia, nutritional anemia, hemolytic anemia, refractory anemia, and normal controls. Results show that with the exception of nutritional anemia cells, erythroid colony formation by all specimens was significantly inhibited (84% to 100%) by 100 to 200 U of either interferon type per milliliter. Erythroid colony formation by nutritional anemia bone marrow cells ws inhibited only 30% to 40% by 200 U/ml fibroblast or leukocyte interferon, and 100 U/ml were ineffective. Sickle cell peripheral blood mononuclear cells and refractory anemia bone marrow demonstrated marked inhibition of colony formation (86% to 97%) with 50 U/ml fibroblast or leukocyte interferon. Inhibition of colony formation by sickle cell peripheral blood mononuclear cells was completely abolished by addition of anti-interferon. Colony formation by refractory anemia bone marrow was inhibited 46% to 51% by as little as 10 U/ml fibroblast or leukocyte interferon. This concentration of interferon was ineffective with cells from thalassemia, secondary polycythemia, nutritional anemia, hemolytic anemia, and controls. Mouse bone marrow colony formation was not suppressed by 200 U/ml leukocyte interferon. These results demonstrate that fibroblast or leukocyte interferons inhibit in vitro erythroid colony formation by human bone marrow or peripheral blood mononuclear cells, the effect is abolished by anti-interferon, and inhibition may be species-specific. These studies reveal that cells obtained from certan patients are particularly sensitive to the cytoxic effects of interferon, and it may be useful to monitor the erythropoietic state of the patient during interferon chemotherapy.
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PMID:Suppressive effect of human interferons on erythroid colony growth in disorders of erythropoiesis. 615 73

Recent developments in recombinant DNA research promise to have a substantial impact on medicine. The technology now allows for DNA pieces to be isolated and ligated to other DNA, such as that from bacteria, and be replicated in foreign hosts. The replicated DNA can then be isolated and used to study its structure, to study gene expression and its regulation, to program microorganisms to synthesize medically, agriculturally or industrally important proteins, to transfer genes back into mammalian cells and to diagnose genetic diseases. The DNA used for cloning can be obtained by copying mRNA, by chemically synthesizing it and by isolating chromosomal DNA; each of these types of DNAs serve special uses. The results of studies with the use of these DNAs have provided an enormous amount of information, in some cases of a quite surprising nature, about the structure and function of genes. This information is already providing substantial insights into the mechanisms of diseases such as cancer and hopefully it will lead to newer therapies as well. The technology had already resulted in the synthesis in microorganisms of a number of useful proteins such as vaccines, insulin and interferon. The use of the DNA to diagnose genetic diseases has been applied as for instance to thalassemia and sickle cell anemia. Finally, the ability to transfer genes back into cells and to have these genes function promises to open a new approach with gene therapy that may be useful for treating not only genetic diseases, but a number of other diseases as well.
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PMID:Tan Sri Runme Shaw lecture. Genetic engineering and its impact on medicine. 635 18

The purpose of this study was to determine whether interferon-alfa (IFN-alpha) therapy benefits patients with transfusion-dependent thalassemia and chronic active hepatitis C, and whether their iron burden modifies the response to this therapy. We conducted a controlled trial of recombinant IFN-alpha (3 million units per square meter of body surface area, three times a week for 15 months) in 65 patients with thalassaemia major and chronic active hepatitis C; 14 of them were untreated control subjects. In 21 of the 51 treated patients, alanine aminotransferase values returned to normal within 6 months, and hepatitis C virus ribonucleic acid was no longer detected in serum; no changes were detected among control subjects. The response to IFN-alpha therapy was inversely related (p < 0.002) to the liver iron burden as assessed by atomic absorption, the histologic semiquantitative method, or both methods. During 3 years of follow-up, two responder patients had relapses. We conclude that IFN-alpha represents a useful therapeutic option for children with transfusion-dependent thalassemia and chronic active hepatitis C with a mild to moderate iron burden.
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PMID:Effect of iron overload on the response to recombinant interferon-alfa treatment in transfusion-dependent patients with thalassemia major and chronic hepatitis C. 802 61

In this open, pilot study, interferon (IFN) alpha-2b seemed effective in the treatment of hepatitis C virus (HCV) infection in patients with beta-thalassaemia. In seven of nine patients who completed the study alanine aminotransferase activities returned to normal, and a completely stable response 24 months after treatment was seen in five. Liver biopsy specimen showed a clear reduction in portal, periportal, and lobular necroinflammation in all five cases. Three patients stopped treatment early because of side effects.
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PMID:Alpha interferon treatment of chronic hepatitis C in beta-thalassaemia. 831 84

Hepatitis C virus (HCV) is responsible for the majority of cases of post transfusion non-A non-B (NANB) hepatitis in thalassaemia major (TM). Twelve multi-transfused TM patients with serological, biochemical, histological and molecular biological evidence of HCV infection have been treated for 6 months with recombinant alpha-interferon (IFN). Ten (83%) responded as assessed by a fall of at least 50% of pre-treatment serum transaminase levels. Histological improvement was observed in 6/7 responders tested. Natural killer (NK) cell activity 24 h after the first dose of IFN was significantly increased in responders as compared to non-responders (P < 0.05). HCV RNA disappeared from serum in 5/12 and from liver tissue in 2/5 of the responders. The degree of induction of peripheral blood mononuclear cell 2'5' oligoadenylate synthetase messenger RNA (2-5 OAS mRNA), an enzyme induced by IFN, after the first dose of IFN did not correlate with response. IFN was generally well tolerated. We conclude that the response rate in multi-transfused TM patients infected with HCV and treated with IFN is similar to that in non-multi-transfused patients.
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PMID:Alpha interferon in the treatment of chronic hepatitis C infection in thalassaemia major. 838 24

Hepatitis C virus (HCV) is responsible for the majority of cases of post transfusion non-A non-B (NANB) hepatitis in thalassaemia major (TM). Fifteen multi-transfused TM patients with serological, biochemical, histological and molecular biological evidence of HCV infection have been treated for six months with recombinant alpha interferon (IFN). Eleven (73%) responded, 8 (53%) had complete response (CR), 3 (20%) partial response (PR) and 4 (27%) did not respond (NR) to IFN. Natural killer (NK) cell activity 24 hours after the first dose of IFN was significantly increased in responders as compared to non-responders. Liver histology showed an overall reduction of portal inflammation and periportal necrosis in the responding patients. HCV RNA disappeared from serum in 8 (15) responders and partial responders. Non responders remained positive. HCV RNA was tested and found to be positive in liver tissue material in 7 patients, five of those were re-tested after IFN treatment. Two became negative (both CR) 3 remained positive despite biochemical response to IFN. The degree of induction of peripheral blood mononuclear cell 2'5' oligoadenylate synthetase messenger RNA (2-5 OAS mRNA), an enzyme induced by IFN, after the first dose of IFN did not correlate with response neither was any significant interaction with cytokines observed; tumour necrosis factor (TNF), interleukin-1. (IL-1) and CD4:CD8 ratios did not change. We conclude that IFN should be given to all TM patients with chronic active hepatitis due to HCV.
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PMID:Recombinant alpha 2B interferon (IFN) in the treatment of chronic hepatitis C disease in thalassaemia major (TM). 839 33

Some 20% of cases of posttransfusion and sporadic hepatitis non-A, non-B are anti-HCV negative. In 1995 it proved possible in collaboration of Genelabs with Boehringer Co. Mannheim to identify a new RNA virus which causes acute and chronic hepatitis in humans and tamarins. The genome of the virus contains some 2900 amino acids, and as to its structure, it resembles flaviviruses. It was described as hepatitis G virus (HGV). It differs from the hepatitis C, virus as it has only a 26% homology of amino acids. It is transmitted through blood during transfusion along with other parenteral routes of infection. Risk groups comprise i.v. drug addicts, blood donors and patients with thalassaemia and repeated blood transfusions. HGV can infect the liver as an independent virus or along with the virus of hepatitis B or C (dual infection). As to clinical aspects, hepatitis G is very mild and not associated with jaundice. Some patients develop chronic hepatitis. About half the patients infected with HGV have only a slightly raised transaminase activity, the remainder have normal liver enzymes. As compared with hepatitis C, the mean transaminase activity is one half. It can be diagnosed by assessment of HGV RNA by means of PCR. In the USA the prevalence of HGV RNA in blood donors with normal ALT activity is 1.7% and in donors with increased ALT activity 1.5%. The virus is sensitive to interferon, after treatment the serum concentration of HGV RNA declines rapidly but after withdrawal of treatment the values return to pre-treatment levels. This is the first report on the newly discovered hepatitis G virus.
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PMID:[The discovery of hepatitis G virus]. 862 84

No experience has been reported to date in treating chronic hepatitis C virus (HCV) infection with interferon (IFN) therapy after BMT, mainly due to concerns related to the impact of an immunomodulatory drug in patients who are immunologic and haematologic chimeras. However, chronic inflammatory activity related to HCV infection results in a chronic fibrogenous mechanism potentially leading to liver cirrhosis and hepatocellular carcinoma. Moreover, patients transplanted for beta-thalassemia could be at greater risk because of concomitant iron overload and pre-existing fibrous liver damage. Eleven patients with serological, biochemical, histological and molecular biological evidence of HCV infection were included in the study and treated for 6-12 months with recombinant IFN 24-65 months following BMT. The serum alanine aminotransferase (ALT) was persistently elevated (range 85-1242 U/l; mean 416) for at least 1 year prior to IFN treatment. Ten patients completed the protocol; five were considered as responders to treatment. In these five patients the liver histology showed an overall reduction of inflammation and necrosis: histological inflammatory activity improved from chronic active hepatitis (CAH) to chronic persistent hepatitis (three patients) or minimal residual inflammatory activity (two patients). The Knodell total activity score varied from 5.4 (range 3-9) to 1.4 (range 1-2; P = 0.05). All responding patients revealed negativization of serum HCV-RNA, that has been persistent in four (follow-up 1-3 years). ALT level fell to 15-80 U/l (mean 52; P = 0.0027). No major complications occurred during the therapy and no influence on marrow engraftment parameters were noted. We conclude that IFN therapy does not adversely interfere with engraftment and that it is a feasible therapy for treatment of chronic hepatitis C virus after BMT.
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PMID:Alpha-interferon treatment of chronic hepatitis C after bone marrow transplantation for homozygous beta-thalassemia. 938 79


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