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Total IgG Levels (total + igg_level)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Proteasome Inhibition Causes Apoptosis of Normal Human Plasma Cells Preventing Alloantibody Production

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 1 2009
D. K. Perry
Antibody production by normal plasma cells (PCs) against human leukocyte antigens (HLA) can be a major barrier to successful transplantation. We tested four reagents with possible activity against PCs (rituximab, polyclonal rabbit antithymocyte globulin (rATG), intravenous immunoglobulin (IVIG) and the proteasome inhibitor, bortezomib) to determine their ability to cause apoptosis of human bone marrow-derived PCs and subsequently block IgG secretion in vitro. IVIG, rituximab and rATG all failed to cause apoptosis of PCs and neither rituximab nor rATG blocked antibody production. In contrast, bortezomib treatment led to PC apoptosis and thereby blocked anti-HLA and antitetanus IgG secretion in vitro. Two patients treated with bortezomib for humoral rejection after allogeneic kidney transplantation demonstrated a transient decrease in bone marrow PCs in vivo and persistent alterations in alloantibody specificities. Total IgG levels were unchanged. We conclude that proteasome activity is important for PC longevity and its inhibition may lead to new techniques of controlling antibody production in vivo. [source]

Pharmacokinetics of intravenous immunoglobulin and outcome in Guillain-Barré syndrome,

ANNALS OF NEUROLOGY, Issue 5 2009
Krista Kuitwaard MD
Objective Intravenous immunoglobulin (IVIg) is the first choice treatment for Guillain-Barré syndrome (GBS). All patients initially receive the same arbitrary dose of 2g per kg body weight. Not all patients, however, show a good recovery after this standard dose. IVIg clearance may depend on disease severity and vary between individuals, implying that this dose is suboptimal for some patients. In this study, we determined whether the pharmacokinetics of IVIg is related to outcome in GBS. Methods We included 174 GBS patients who had previously participated in 2 randomized clinical trials. At entry, all patients were unable to walk unaided and received a standard dose of IVIg. Total IgG levels in serum samples obtained immediately before and 2 weeks after the start of IVIg administration were determined by turbidimetry and related to clinical outcome at 6 months. Results The increase in serum IgG (,IgG) 2 weeks after IVIg treatment varied considerably between patients (mean, 7.8g/L; standard deviation, 5.6g/L). Patients with a low ,IgG recovered significantly more slowly, and fewer reached the ability to walk unaided at 6 months (log-rank p < 0.001). In multivariate analysis adjusted for other known prognostic factors, a low ,IgG was independently associated with poor outcome (p = 0.022). Interpretation After a standard dose of IVIg treatment, GBS patients show a large variation in pharmacokinetics, which is related to clinical outcome. This may indicate that patients with a small increase in serum IgG level may benefit from a higher dosage or second course of IVIg. Ann Neurol 2009;66:597,603 [source]

Lower antibody response to Porphyromonas gingivalis associated with immunoglobulin G Fc, receptor IIB polymorphism

JOURNAL OF PERIODONTAL RESEARCH, Issue 6 2008
Y. Honma
Background and Objective:, Human Fc,RIIB is one of the receptors for immunoglobulin G (IgG) and suppresses the activation of B lymphocytes through cross-linking with the B cell receptor via immune complexes. This function of Fc,RIIB is essential for the negative regulation of antibody production. Our previous study has demonstrated the gene polymorphism Fc,RIIB-I232T to be associated with periodontitis. The polymorphism Fc,RIIB-232T has been reported to inhibit B-cell antigen receptor signaling more effectively compared to Fc,RIIB-232I, while other groups concluded that Fc,RIIB-232T had no ability to inhibit activatory receptors. In this study, we examined whether Fc,RIIB-I232T polymorphism would change the IgG antibody response to the periodontopathic bacteria Porphyromonas gingivalis. Material and Methods:, Forty-seven patients with periodontitis were genotyped with the direct sequencing of genome DNA. Serum IgG and specific IgG subclass levels for the sonicate of P. gingivalis and the recombinant 40 kDa outer membrane protein (OMP) were determined. Results:, No significant difference in the total IgG level and IgG response to P. gingivalis sonicate were observed between sera from Fc,RIIB-232T carriers and non-carriers. The Fc,RIIB-232T carriers revealed a significantly lower IgG2 response to P. gingivalis 40 kDa OMP compared to non-carriers (p = 0.04, Mann,Whitney U -test). Lower responses of Fc,RIIB-232T carriers were also observed in specific IgG and IgG1 levels. The Fc,RIIB-232T carriers revealed a low level of IgG2 response to P. gingivalis 40 kDa OMP, even with a high average probing pocket depth. Conclusion:, These results suggest that association of the Fc,RIIB-232T allele with periodontitis might be related to the lower levels of antibody response to P. gingivalis. [source]

Changes of Circulating Antibody Levels Induced by ABO Antibody Adsorption for ABO-Incompatible Kidney Transplantation

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 5 2009
P. V. Valli
ABO-incompatible kidney transplantation using immunoadsorption to remove anti-A/B antibodies has become a successful clinical practice. Since the data on the specificity of the ABO columns are controversial, the present study assessed the efficiency and specificity of the ABO immunoadsorption, the effect on total immunoglobulins and antibodies previously induced by vaccination. Anti-A/B antibodies were measured by agglutination and ABO flow cytometry, total IgG/IgM, carbohydrate- and protein-specific antibodies by nephelometry and ELISA. The first immunoadsorption not only efficiently reduced donor-specific anti-A/B IgM (81%) and IgG (56%) but also reduced compatible anti-A/B IgM (59%) and IgG (34%). The measurements of antidonor A/B antibodies by direct agglutination (IgM) or flow cytometry better represented the effective antibody levels than the indirect agglutination test (IgG). The median reduction of total IgM and total IgG levels after a single immunoadsorption was 34% and 18%, respectively. Antibodies against pneumococcus and haemophilus polysaccharide antigens were significantly reduced, whereas antitetanus and antidiphtheria protein antibodies were not affected. Intravenous immunoglobulin administration restored the protective anticarbohydrate antibody levels. In summary, immunoadsorption efficiently removed antidonor A/B antibodies, but was not specific for A/B antigens. Anti-A/B antibody levels as determined by ABO flow cytometry are useful to establish the minimal number of immunoadsorptions needed for successful ABO-incompatible transplantation. [source]