Beta-2-microglobulin (β2m) is the light chain of the major histocompatibility complex (MHC) class I cell surface heterodimer. β2m is well conserved across most species with few polymorphisms seen within species. The aims of this study were to clone and express ovine β2m and investigate if allelic variation of ovine β2m exists. Ovine β2m clones were isolated from five sheep of three breeds by reverse-transcription polymerase chain reaction (RT-PCR). Sequence analysis showed that four ovine β2m sequences were obtained. Within breeds and individual animals there was evidence of allelic variation of ovine β2m. An expression system was established to express one of the alleles with an ovine MHC class I cDNA clone in human embryo kidney cells (HEK293) and quail cells (QT35). Transfection experiments showed that ovine β2m was expressed and directed the expression of ovine MHC class I heavy chain to the cell surface of the transfected cells. Both bovine and human β2m supported ovine MHC class I heavy chain cell surface expression.
Changxin Wua, Ian McConnella and Barbara Blacklaws
ARTICLE
Friday
Beta-2-microglobulin level predicts outcome following autologous hematopoietic stem cell transplantation in patients with multiple myeloma
Despite the widespread use of high-dose therapy combined with autologous hematopoietic stem cell transplantation (autoHSCT), the outcomes of multiple myeloma (MM) treatment remain variable. The aim of this study was to define pretransplantation factors that influence outcomes following autoHSCT in patients with MM. Eighty-one MM patients, aged 51 years (range 31-70 years), undergoing first autoHSCT were included in the analysis. Thirty patients were in complete remission and 51 were in partial remission.
The conditioning regimen was based mainly on melphalan (200 mg/m(2) intravenous [iv]). The following factors were tested for their prognostic significance: beta-2-microglobulin (B2M), lactate dehydrogenase , monoclonal protein level, bone marrow plasma cell percentage (PL), hemoglobin level, age, interval from diagnosis to autoHSCT, and number of transplanted CD34-positive cells.
The transplant-related mortality at day 100 was 3.7% (3/81). The incidence of progression at 9.2 years was 71% for patients with elevated B2M, and 32% for those where B2M was within normal limits (P = .02.) The probability of PFS was decreased for patients with B2M > or = versus < normal limits (29% vs 68%; P = .02) and PL > or = versus < 5% (0% vs 45%; P = 0.03).
In a multivariate analysis B2M remained the only factor associated with increased risk of progression (relative risk [RR] = 3.3; P = .03) and reduced probability of PFS (RR = 3.3; P = .03). We concluded that B2M level measured at first autoHSCT was a useful predictor for progression and PFS in MM patients.
Stella-Holowiecka B, Czerw T, Holowiecka-Goral A, Giebel S, Wojnar J, Holowiecki J.
Department of Hematology and Bone Marrow Transplantation, Silesian Medical University, Katowice, Poland. klinem@sum.edu.pl.Transplant Proc. 2007 Nov;39(9):2893-7
The conditioning regimen was based mainly on melphalan (200 mg/m(2) intravenous [iv]). The following factors were tested for their prognostic significance: beta-2-microglobulin (B2M), lactate dehydrogenase , monoclonal protein level, bone marrow plasma cell percentage (PL), hemoglobin level, age, interval from diagnosis to autoHSCT, and number of transplanted CD34-positive cells.
The transplant-related mortality at day 100 was 3.7% (3/81). The incidence of progression at 9.2 years was 71% for patients with elevated B2M, and 32% for those where B2M was within normal limits (P = .02.) The probability of PFS was decreased for patients with B2M > or = versus < normal limits (29% vs 68%; P = .02) and PL > or = versus < 5% (0% vs 45%; P = 0.03).
In a multivariate analysis B2M remained the only factor associated with increased risk of progression (relative risk [RR] = 3.3; P = .03) and reduced probability of PFS (RR = 3.3; P = .03). We concluded that B2M level measured at first autoHSCT was a useful predictor for progression and PFS in MM patients.
Stella-Holowiecka B, Czerw T, Holowiecka-Goral A, Giebel S, Wojnar J, Holowiecki J.
Department of Hematology and Bone Marrow Transplantation, Silesian Medical University, Katowice, Poland. klinem@sum.edu.pl.Transplant Proc. 2007 Nov;39(9):2893-7
Wednesday
What Is Beta 2 Microglobulin
Beta 2 microglobulin is a component of major histocompatibility complex (MHC) class I molecules, which are present on almost all cells of the body red blood cells are a notable exception. Beta 2 microglobulin lies lateral to the alpha 3 chain on the cell surface.
Beta 2 microglobulin is a small protein normally found on the surface of many cells, including lymphocytes, and in small amounts in the blood and urine . Testing is done primarily when evaluating a person for certain kinds of cancer affecting white blood cells including chronic lymphocytic leukemia , non-Hodgkin's lymphoma, and multiple myeloma or kidney disease .
beta 2-Microglobulin (beta 2M), an interesting and underutilized metabolite, can be used in assessing renal function , particularly in kidney-transplant recipients and in patients suspected of having renal tubulointerstitial disease . It also can serve as a nonspecific but relatively sensitive marker of various neoplastic, inflammatory, and infectious conditions.(1)
(1) Annals of Clinical and Laboratory Science , Vol 20, Issue 3, 163-168
Beta 2 microglobulin is a small protein normally found on the surface of many cells, including lymphocytes, and in small amounts in the blood and urine . Testing is done primarily when evaluating a person for certain kinds of cancer affecting white blood cells including chronic lymphocytic leukemia , non-Hodgkin's lymphoma, and multiple myeloma or kidney disease .
beta 2-Microglobulin (beta 2M), an interesting and underutilized metabolite, can be used in assessing renal function , particularly in kidney-transplant recipients and in patients suspected of having renal tubulointerstitial disease . It also can serve as a nonspecific but relatively sensitive marker of various neoplastic, inflammatory, and infectious conditions.(1)
(1) Annals of Clinical and Laboratory Science , Vol 20, Issue 3, 163-168
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