transforming-growth-factor-beta and Hemoglobinuria--Paroxysmal

Paroxysmal nocturnal hemoglobinuria (PNH) is an acquired clonal hematopoietic stem cell disorder caused by a mutation of the X-linked PIGA gene, resulting in a deficient expression of glycosylphosphatidylinositol (GPI)-anchored proteins. While large clonal expansions of GPI(-) cells cause hemolytic symptoms, tiny GPI(-) cell populations can be found in healthy individuals and remain miniscule throughout life. The slight expansion of PNH clones often occurs in patients with acquired aplastic anemia (AA), an autoimmune bone marrow (BM) failure caused by autoreactive cytotoxic T lymphocyte attack on hematopoietic stem and progenitor cells (HSPCs). The presence of PNH clones is thought to represent the immune pathophysiology of BM failure and be derived from GPI(-) HSPCs that evaded immune attack against HSPCs. However, which mechanisms underlie the selection of GPI(-) HSPCs as well as their overwhelming clonal expansion remains unclear. Ancestral or secondary somatic mutations in GPI(-) HSPCs contribute to the clonal expansion of the aberrant HSPCs in certain patients with PNH; however, it remains unclear whether such driver mutations are responsible for clonal expansion of all patients. Increased sensitivity to TGF-β in GPI(-) HSPCs partly explains the predominance of GPI(-) erythrocytes in immune-mediated BM failure. CD4

Topics: Bone Marrow Failure Disorders; Glycosylphosphatidylinositols; Hemoglobinuria, Paroxysmal; Humans; Membrane Proteins; Mutation; Transforming Growth Factor beta

While the incidence of paroxysmal nocturnal hemoglobinuria (PNH) is relatively high in Northern China, the exact mechanism of the disease remains unknown. Immunoregulatory cytokine polymorphisms can directly regulate the expression levels of cytokines, which play a crucial role in many diseases. The purpose of this study was to study cytokine gene single nucleotide polymorphisms (SNPs) and the correlated cytokine expression levels in relationship to the PNH pathogenesis.. Peripheral blood samples were collected from 30 PNH patients and 40 healthy donors; all of the samples were collected from the Han people of Northern China. Eight SNP loci in five cytokine genes, including tumor necrosis factor-alpha (TNF-α), interferon-gamma (IFN-γ), transforming growth factor-beta (TGF-β), interleukin-6 (IL-6), and IL-10, and aplastic anemia (AA) were assessed. TNF-a, TGF-b, IFN-g, IL-6, and IL-10 were analyzed by sequence-specific primer polymerase chain reaction (PCR-SSP). The plasma protein levels of TNF-a, TGF-b, and IFN-g were assessed by an ELISA.. The PNH patients had a lower frequency of the TC/GG genotype of the TGF-b gene (P < 0.01) and a higher frequency of the C allele in the TGF-b gene (+10) compared to the controls (P < 0.05). The predominant genotype of the +874 locus of the IFN-g gene was TA in the PNH patients, while that in the predominant genotype was AA in the control group and was statistically significant (P < 0.001). The frequency of the T allele in the IFN-g gene was dramatically higher in the PNH patients than in the controls (P < 0.05). The PNH patients had a reduced frequency of the GC and CC genotypes, as well as the C allele at locus -174 of the IL-6 gene compared to the controls (P < 0.01). In addition, the plasma concentrations of TNF-a, TGF-b, and IFN-g were significantly higher in the PNH group compared to the control group (P < 0.01).. Expression levels of the TNF-a, TGF-b, and IFN-g cytokines play an important role in PNH. The GC and CC genotypes, as well as the C allele of the IL-6 gene may protect the Han people of Northern China against PNH. Additionally, the TC/GG genotype of the TGF-b gene may be the protective allele. In contrast, the TA genotype and the T allele for the IFN-g gene, as well as the C allele of TGF-b may be susceptible to PNH. However, SNPs in the TNF-a and IL-10 genes did not correlate with PNH development. Alternatively, the increased plasma concentrations of TNF-a, TGF-b, and IFN-g in PNH patients may also be related to PNH development.

Topics: Adult; Aged; Alleles; Anemia, Aplastic; Asian People; China; Cytokines; Enzyme-Linked Immunosorbent Assay; Female; Genotype; Hemoglobinuria, Paroxysmal; Humans; Interferon-gamma; Interleukin-10; Interleukin-6; Male; Middle Aged; Polymorphism, Genetic; Polymorphism, Single Nucleotide; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Young Adult

Glycosylphosphatidylinositol-anchored protein-deficient (GPI-AP(-) ) T cells can be detected in some patients with bone marrow failure (BMF), but the link between these cells and BMF pathophysiology remains to be elucidated. To clarify the significance of GPI-AP(-) T cells in BMF, peripheral blood from 562 patients was examined for the presence of CD48(-) CD59(-) CD3(+) cells using high-resolution flow cytometry (FCM), and the GPI-AP(-) T cells were characterized with regard to their phenotype and sensitivity to inhibitory molecules, including herpesvirus entry mediator (HVEM) and a myelosuppressive cytokine, TGF-β. A multi-lineage FCM analysis detected CD48(-) CD59(-) CD3(+) T cells in 72 (12.8%) of the patients, together with GPI-AP(-) myeloid cells. Unexpectedly, 12 patients (10 with aplastic anemia and 2 with myelodysplastic syndrome-refractory anemia, 2.1%), who showed clinical features similar to those of other BMF patients with GPI-AP(-) myeloid cells, such as a good response to immunosuppressive therapy, displayed 0.01-0.3% GPI-AP(-) cells exclusively in T cells. The CD48(-) CD59(-) T cells consisted of predominantly effector memory (EM) and terminal effector cells, while CD48(-) CD59(-) T cells from non-BMF patients who had received anti-CD52 antibody only showed EM and central memory phenotypes. TGF-β and HVEM capable of inhibiting T-cell proliferation via its GPI-AP CD160 ligation suppressed the in vitro proliferation of GPI-AP(+) T cells more potently than that of GPI-AP(-) T cells from the same patients. The presence of GPI-AP(-) T cells, as well as GPI-AP(-) myeloid cells, may therefore reflect the immunopathophysiology of BMF in which cytokine-mediated suppression of hematopoietic stem cells via GPI-AP-type receptors takes place.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Anemia, Aplastic; Bone Marrow Diseases; Bone Marrow Failure Disorders; Case-Control Studies; Child; Child, Preschool; Female; GPI-Linked Proteins; Hematopoietic Stem Cells; Hemoglobinuria, Paroxysmal; Humans; Immunophenotyping; In Vitro Techniques; Infant; Male; Membrane Proteins; Middle Aged; Myelodysplastic Syndromes; Myeloid Cells; Receptors, Tumor Necrosis Factor, Member 14; T-Lymphocytes; Transforming Growth Factor beta; Young Adult

To explore whether predisposition to bone marrow failure syndromes (BMF), such aplastic anemia (AA), paroxysmal nocturnal hemoglobinuria (PNH) and myelosysplastic syndromes (MDS), is found in killer cell immunoglobulin-like receptor (KIR) and human leukocyte antigen (HLA) ligand (KIR-L) gene variations or cytokine polymorphisms.. We studied a cohort of 77 patients with AA, 129 with MDS and 285 healthy controls for the frequencies of KIR-L and KIR genotypes and 22 selected single nucleotide polymorphisms (SNPs) located within 10 cytokine (IL-1α, IL-1β, IL-2, IL-4, IL-6, IL-10, IL12, IFN- γ, TNF- α, TGF- β) and 3 cytokine receptor (IL-1R, IL-1RA, IL-4Rα) genes.. In AA we found a decreased frequency of inhibitory KIR-2DL3 genes. In MDS, no difference in the frequency of KIR genotype was identified; however, a decreased frequency of 2DL3 was found in hypocellular MDS. Analysis of the KIR genotype in correlation with the corresponding KIR-L profile, revealed a decreased frequency of stimulatory 2DS1/C2 mismatch both in AA and MDS. In AA and MDS cohorts, compared to controls, we found a higher frequency of TT codon 10 variant and of GG codon 25 variant of TGF- β gene, consistent with a high secretory phenotype. This relationship was even more pronounced in PNH and hypocellular MDS. We confirm that the hypersecretory genotype T/T at position -874 of INF-γ gene was overrepresented only in AA and correlates with presence of a PNH clone. Instead in MDS patients, the frequency of G/A polymorphism at position -308 on the TNF- α gene promoter, which correlates with higher TNF- α production, was found significantly higher. Moreover, hypocellular MDS was characterized by a higher prevalence of IL-10 GCC/GCC haplotype, which is functionally associated with a low secretor phenotype.. Our findings suggest that alterations in KIR/KIR-L matching, such as increased 3DL2 and decreased 2DS1 mismatch, and in the polymorphisms of TGFβ1, IFN-γ, TNF- α and IL-10 may account for the propensity to immunemediated killing of hematopoietic stem cells and/or ineffective hematopoiesis characteristic of AA and MDS. Further studies are needed to elucidate whether these immunogenetic traits may be involved in increased risk of developing immune-mediated BMF.

Topics: Adolescent; Adult; Aged; Anemia, Aplastic; Bone Marrow Diseases; Bone Marrow Failure Disorders; Child; Child, Preschool; Cohort Studies; Cytokines; Gene Frequency; Genotype; Hemoglobinuria, Paroxysmal; Humans; Interferon-gamma; Interleukin-10; Middle Aged; Myelodysplastic Syndromes; Polymorphism, Single Nucleotide; Receptors, Cytokine; Receptors, KIR; Transforming Growth Factor beta

Topics: Adult; Bone Marrow Transplantation; Case-Control Studies; Cytokines; Follow-Up Studies; Hemoglobinuria, Paroxysmal; Humans; Interferon-gamma; Interleukin-2; Leukocytes, Mononuclear; Male; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Campath-1H, an anti-CD52 monoclonal antibody, is therapeutically active in lymphoproliferative and autoimmune diseases. After Campath-1H therapy, lymphocytes with a paroxysmal nocturnal haemoglobinuria (PNH) phenotype have been reported to emerge. We characterized a PNH-like lymphocyte population emerging after Campath-1H therapy, in a patient with fludarabine refractory B-cell chronic lymphocytic leukaemia (B-CLL). We demonstrated a reduction in PIG-A mRNA levels compared with controls, and of all cytokines tested [interleukin (IL)-4, IL-13, IL-2, interferon(IFN)-gamma, IL-6, IL-10, and tumour necrosis factor (TNF)-alpha], except transforming growth factor (TGF)-beta. Given the inhibitory activity of TGF-beta, its elevated levels may contribute to the selective pressure of Campath-1H, leading to the emergence of PNH-like lymphocytes.

Topics: Alemtuzumab; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antibodies, Neoplasm; Case-Control Studies; Flow Cytometry; Hemoglobinuria, Paroxysmal; Humans; Interferon-gamma; Interleukin-10; Interleukin-13; Interleukin-2; Interleukin-4; Interleukin-6; Leukemia, Lymphocytic, Chronic, B-Cell; Lymphocytes; Male; Membrane Proteins; Middle Aged; Phytohemagglutinins; Polymorphism, Single-Stranded Conformational; RNA, Messenger; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha