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)

To examine any role of the high affinity Fcgamma class I receptor (FcgammaRI) (CD64) in erythrocyte elimination by mononuclear phagocytes (MP) in thalassaemia (thal), we investigated the in vitro interaction of beta-thalassaemic erythrocytes with monocytes (Mo) whose FcgammaR expression had been modulated by cytokines. Treatment of Mo with interferon (IFN)-gamma or interleukin (IL)-10 which up-regulate FcgammaRI, caused a dose-dependent increase in binding of beta-thalassaemic erythrocytes, whereas stimulation with IL-4 which down-regulates the receptor, reduced this interaction, in a dose-dependent manner, to that of normal erythrocytes. Binding of thalassaemic erythrocytes by IFN-gamma or IL-10-treated Mo was inhibited by FcgammaRI-specific reagents. In addition, Mo expression of FcgammaRI and HLA class II DR was determined by flow cytometry in Thai patients with HbH disease (alpha1/alpha2 or alpha1/Hb Constant Spring) (n = 15) or beta degrees -thal/HbE (n = 16). In both groups of patients FcgammaRI expression was increased as compared to normal controls (n = 14): mean fluorescence intensity (+/-SD) 124.79 +/- 38. 77 in HbH disease and 121.86 +/- 18.23 in beta degrees -thal/HbE versus 91.94 +/- 17.36 in normal controls (P < 0.01 and P < 0.001, respectively). In contrast, HLA class II DR expression was similar in patients and controls. The results suggest that, in thalassaemia, up-regulated FcgammaRI on mononuclear phagocytes plays a role in their interaction with erythrocytes and that this process can be modified by cytokines.
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PMID:Role of FcgammaRI (CD64) in erythrocyte elimination and its up-regulation in thalassaemia. 1051 93

Mixed hemopoietic chimerism has the potential to correct genetic hemological diseases (sickle cell anemia, thalassemia) and eliminate chronic immunosuppressive therapy following organ transplantation. To date, most strategies require either recipient conditioning (gamma-irradiation, depletion of the peripheral immune system) or administration of "mega" doses of bone marrow to facilitate reliable engraftment. Although encouraging, many issues remain that may restrict or prevent clinical application of such strategies. We describe an alternative, nonirradiation based strategy using a single dose of busulfan, costimulation blockade, and T cell-depleted donor bone marrow, which promotes titratable macrochimerism and a reshaping of the T cell repertoire. Chimeras exhibit robust donor-specific tolerance, evidenced by acceptance of fully allogeneic skin grafts and failure to generate donor-specific proliferative responses in an in vivo graft-versus-host disease model of alloreactivity. In this model, donor cell infusion and costimulation blockade without busulfan were insufficient for tolerance induction as donor-specific IFN-gamma-producing T cells re-emerged and skin grafts were rejected at approximately 100 days. When applied to a murine beta-thalassemia model, this approach allows for the normalization of hemologic parameters and replacement of the diseased red cell compartment. Such a protocol may allow for clinical application of mixed chimerism strategies in patients with end-stage organ disease or hemoglobinopathies.
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PMID:Costimulation blockade, busulfan, and bone marrow promote titratable macrochimerism, induce transplantation tolerance, and correct genetic hemoglobinopathies with minimal myelosuppression. 1144 Nov 22

Iron is a crucial element for many central metabolic pathways of the body. Lack of iron leads to growth arrest and anaemia while increased accumulation of this metal, as it occurs in highly frequent inherited diseases such as hereditary haemochromatosis and thalassaemia, is associated with toxic radical formation and progressive tissue damage. As shown by several groups, iron also modulates immune effector mechanisms, such as cytokine activities (IFN-gamma effector pathways towards macrophages), nitric oxide (NO) formation or immune cell proliferation, and thus host immune surveillance. Therefore, gaining control over iron homeostasis is one of the central battlefields in deciding the fate of an infection with intracellular pathogens or a malignant disease. Thus, the reticulo-endothelial system has evoked sophisticated strategies to control iron metabolism in general and especially the handling of the metal within immune cells.
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PMID:Iron and immunity: a double-edged sword. 1188 35

Thalassemia major is an inherited disorder particularly common in people of Mediterranean, African, and Southeast Asian ancestry. Hepatitis C virus (HCV) is responsible for 80 - 90% of post transfusion hepatitis in beta-Thalassemic patients. Marked liver iron overload, which is often inevitable in patients on regular blood transfusion, and HCV infection have been shown to have a potentiating effect on hepatic fibrogenesis in thalassemic patients. This study aimed at investigating the impact of combined chronic hepatitis C and beta-Thalassemia on innate and adaptive immune responses. The study was conducted on 60 patients and 15 apparently healthy controls. Patients were dived into three groups: group 1: 35 patients with combined beta-thalassemia and chronic hepatitis C (CHC) (betaTH/CHC), group II: 15 beta-thalassemia patients without HCV infection (betaTH), group III: 10 patients with chronic hepatitis C infection (CHC). Assessment of the number of CD3+, CD4+, CD8+ T cells, NK cells, and NKT cells was done by flowcytometry. Human IFN-delta and IL-15 levels were estimated by Enzyme -Linked Immunosorbent Assay (ELISA). betaTH/CHC patients had significantly reduced numbers of conventional T lymphocytes, NK, NKT, CD4+, and CD8+ T cells when compared to betaTH patients. Serum IFN-gamma levels were significantly reduced in betaTH/CHC patients (2.57 pg/ml) in comparison to CHC patients (6.89pg/ml) and normal controls (4.73 pg/ml). A significant elevation of serum IL-15 levels in betaTH/CHC patients (38.04pg/ml) was found when compared to betaTH patients (16.22 pg/ml). Splenectomized patients showed reduced numbers of NK cells, NK T cells and lower CD4:CD8 ratio in comparison to non-splenectomized ones among betaTH/CHC patients. In conclusion our data show an obvious defective cellular innate immunity (NK & NKT cells) and cellular adaptive immunity (CD4+ T cells, CD8+ T cells, & INF-gamma) in (betaTH/CHC) patients, in comparison to (betaTH) patients. This observation suggests a potentiating effect of both CHC and beta-thalassemia on depression of innate and adaptive immune status in these patients
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PMID:A study of innate and adaptive immune responses in beta-thalassemic patients with chronic hepatitis C virus infection. 2308 81

Patients with beta-thalassaemia increase the risk of bacterial infections, particularly Burkholderia pseudomallei (Bp), the causative agent of melioidosis in Thailand. Impaired immune cell functions may be the cause of this susceptibility, but detailed mechanisms have not been defined. In this study, we observed impaired production of IFN-gamma and IL-10 by whole blood from beta-thalassaemia patients upon stimulation with a range of bacteria-derived stimuli. In contrast, IFN-gamma response via TCR and plasma IgG specific for Bp were still intact. Importantly, mRNA expression of heme oxygenase 1 (HO-1), a potential modulator of immune function, was increased in whole blood from beta-thalassaemia patients, either with or without stimulation with Bp in vitro. Induction of HO-1 by hemin or CoPP in vitro reduced production of IFN-gamma and IL-10 from healthy human PBMCs and decreased bacterial clearance activity of whole blood from healthy controls and beta-thalassaemia, while inhibition of HO-1 by SnPP enhanced both functions in healthy controls. These results were confirmed to some extent in purified human monocytes of healthy controls. Our results suggest a mechanism that excess hemin of beta-thalassaemia patients is a significant cause of immune suppression via HO-1 induction and may underlie the susceptibility of these individuals to severe bacterial infection.
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PMID:Immune responses in beta-thalassaemia: heme oxygenase 1 reduces cytokine production and bactericidal activity of human leucocytes. 3258 Dec 38