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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We observed and characterized paraproteins present in the serum of seven human immunodeficiency virus type 1 (HIV-1)-infected individuals. Immunoglobulin (Ig) subclass typing performed on these paraproteins identified five as IgG1 kappa, one as an IgG3 lambda, and one as an IgA lambda. The IgG1 kappa paraproteins, purified by high-pressure liquid chromatography, contained the majority of anti-HIV-1 antibody reactivity present in the five serum specimens (ranging from 1:5,000 to 1:500,000) as demonstrated by immunoblot. All five IgG1 paraproteins had at least two light chain species as demonstrated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), and the antibodies were reactive with multiple HIV-1 viral antigens. In contrast, the electrophoretically purified IgG3 lambda and IgA lambda paraproteins did not react with HIV-1 antigens and only one light chain species was detected by SDS-PAGE. The subsequent clinical evaluation of these patients following the initial observation of paraproteinemias failed to correlate the presence of paraproteins with the development of lymphoma over a 2 to 3 year period. These data support the hypothesis that IgG1 paraproteins present in the sera of HIV-1 infected individuals reflect a normal albeit exuberant polyclonal immune response to HIV-1 viral antigens. In contrast, the clinical significance of an IgG3 lambda or an IgA lambda paraprotein is unclear at present.
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PMID:The clinical significance of human immunodeficiency virus type 1-associated paraproteins. 280 75

Cerebrospinal fluid (CSF) and serum samples from 17 patients seropositive for the human immunodeficiency virus (HIV) were analysed for specific IgG1-4 against HIV and cytomegalovirus (CMV). Measles IgG was studied as a reference to detect blood-brain barrier (BBB) defects. All patients had IgG1 antibodies against HIV in both CSF and serum, and all had CMV IgG1 in serum (16 in CSF). Anti-HIV IgG was synthesised intrathecally in 11 patients, IgG3 in three patients, and IgG4 in three patients. Intrathecal production of anti-CMV IgG1 was found in three patients, IgG2 in one, IgG3 in three, and IgG4 in one. Intrathecal anti-HIV IgG synthesis could be demonstrated in all stages of the disease. Analysis of all IgG subclasses allowed intrathecal HIV and/or IgG production to be detected also in patients in whom intrathecally synthesised IgG was restricted to IgG2, 3, or 4. The expression of HIV-specific IgG subclasses in CSF and serum was more restricted in AIDS patients than in HIV-infected persons without clinical AIDS. On the contrary, the largest number of CMV-specific IgG subclasses was found in AIDS patients. Intrathecal HIV or CMV IgG subclass production was seen both with and without neurological symptoms. The peripheral T4 cell counts were not obviously related to neurological symptoms. Even patients with low peripheral T4 cell counts had evidence of intrathecal antibody synthesis against HIV and sometimes CMV, suggesting a retained helper function of T cells in the central nervous system.
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PMID:IgG subclass reactivity against human immunodeficiency virus (HIV) and cytomegalovirus in cerebrospinal fluid and serum from HIV-infected patients. 284 44

Immunoglobulin G subclass titers to three herpesviruses (herpes simplex; HSV; cytomegalovirus, CMV; varicella zoster virus, VZV) were examined in patients with common variable immunodeficiency (CVI) before and after immunoglobulin substitution. Like healthy controls, CVI patients expressed IgG1 and IgG3 to HSV and CMV, but only IgG1 to VZV. Individual titers varied as in healthy individuals, but as a mean, specific IgG titers were lowered in proportion to the decrease of total IgG. HSV and CMV IgG3 titers were relatively higher than the IgG1 titers in CVI patients, resulting in a lower IgG1/IgG3 ratio than in healthy individuals (P = 0.025 and 0.05, respectively). The high IgG3 titers in CVI patients could be due to subclinical reactivations of HSV and CMV in these patients. Low VZV IgG1 and absence of IgG3 could explain the increased frequency of zoster infections reported in CVI patients. After immunoglobulin substitution, herpesvirus-specific IgG1 titers increased while HSV and CMV IgG3 decreased or remained stationary. In two unsubstituted patients, HSV and CMV titers remained stationary during 1 and 5 years, respectively, while an increase of VZV IgG1 and IgG3 indicated VZV reactivation although the patients remained asymptomatic.
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PMID:IgG subclass distribution of antiviral antibodies in common variable immunodeficiency: effect of substitution therapy. 284 90

Serum IgG subclass levels were measured using an indirect competitive immunoenzymatic assay with monoclonal antibodies in 221 patients affected with definite immunodeficiency (ID) syndromes and 229 patients presenting with infection patterns suggestive of ID, but with normal immunoglobulin class levels and no clear evidence of ID. In common variable ID and IgG-IgA deficiency with normal or high IgM, subclass imbalance (mostly IgG1-IgG3 or IgG2-IgG4 deficiency) was the rule, with a higher incidence of severe infections in IgG2-IgG4 defects. One-fifth of patients with IgA deficiency, especially those with autoimmune cytopenia, had subclass deficiencies with no significant correlation with the occurrence of infections. Subclass (mostly IgG2-IgG4) deficiencies were also observed in severe combined ID, defective expression of HLA class II antigens, chronic mucocutaneous candidiasis, and IgM deficiency. Subclass levels were normal in all but one (who was IgG3 deficient) patient with the Wiskott-Aldrich syndrome and in the Buckley's syndrome, except for an unusual patient who presented with low IgG and IgA levels. Subclass (mainly IgG2) deficiency occurred in 24% of infected patients without known ID.
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PMID:Serum IgG subclass levels in patients with primary immunodeficiency syndromes or abnormal susceptibility to infections. 292 38

Immunoblastic lymphadenopathy (IBL)-like T-cell lymphoma is a distinct peripheral T-cell lymphoma, which closely resembles angioimmunoblastic lymphadenopathy with dysproteinemia (AILD) and/or IBL, but is characterized by focal or sheet-like proliferation of immunoblasts and pale cells of T-cell nature. In this report, 36 patients with IBL-like T-cell lymphoma were analyzed. The disease is clinically characterized by generalized lymph node swelling, hepatosplenomegaly, fever, skin rash, polyclonal hypergammaglobulinemia, marked male predominance, predilection for the elderly, and poor prognosis. There was no association with human T-cell leukemia virus type I or human immunodeficiency virus. IBL-like T-cell lymphoma may be divided into two categories (CD4+ type and CD8+ type) by surface marker analysis. It can also be divided into three categories on the basis of the histologic findings of distribution of morphologically recognizable tumor cells: nine cases of "inconspicuous type," six cases of "patchy type," and 21 cases of "diffuse type." Two cases of "inconspicuous type" converted later to "diffuse type." DNA hybridization analyses in the ten recent cases revealed that three of four "inconspicuous types" and five of six "diffuse types" showed clonal rearrangement of T-cell receptor-beta chain gene without rearrangement of immunoglobulin heavy chain gene, providing strong evidence for clonal proliferation of T cells.
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PMID:Clinicopathologic, immunophenotypic, and immunogenotypic analyses of immunoblastic lymphadenopathy-like T-cell lymphoma. 304 80

CNA/N mice bearing the X-linked immunodeficiency (xid) gene(s) demonstrate overall decreased numbers of B-cells, impaired immune responses to TI-2 antigens and decreased serum IgM, IgG3 and to a lesser extent IgG1 and IgA. In these experiments we examined equal number of B-cells (cells capable of regeneration of surface Ig) from PP, MLN and spleens of xid and control mice for immunoglobulin gene expression. B-cells present in CBA/N mice exhibit control levels of Ig isotype-specific mRNA accumulation and transcription. Oligonucleotide probes directed against membrane and secreted exons of mu, gamma and alpha genes were synthesized and hybridized to B-cell RNA from CBA/N and CBA/J mice to determine relative levels of each isotype- and exon-specific mRNA. Results revealed decreased alpha s RNA: alpha m RNA in splenic B-cells of xid mice when compared to control animals. Northern blot analysis of total tissue polysomal RNA demonstrated enhanced expression of the (larger) membrane form of alpha-mRNA (alpha m-RNA) of CBA/N when compared to CBA/J mice. This was especially apparent in splenic preparations; these and other studies have shown that both control and xid PP and MLN express enhanced levels of the membrane forms of each Ig heavy chain isotype RNA when compared to splenic RNA levels. These data suggest the presence of a defective regulation of membrane and secreted alpha in B-cell subpopulations of xid mice.
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PMID:Immunoglobulin gene expression in xid mice: defective expression of secreted and membrane alpha-heavy chain RNA. 311 16

The classes, subclasses and light chain types of 78 serum monoclonal immunoglobulins (MoIg) from adult patients affected with various clinical forms of human immunodeficiency virus (HIV) infection were studied by a sensitive Western blot technique. The incidence of MoIg-containing sera was 26% in a systematic study. Most of these sera contained several (up to eight) detectable MoIg. These MoIg were IgG (91%) and IgM (9%) with a predominance of light chains of the lambda type (kappa:lambda ratio 0.6). The subclass distribution of monoclonal IgG was strikingly different from that observed in myeloma; much less IgG1 and much more IgG3 and IgG4.
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PMID:Isotypy of serum monoclonal immunoglobulins in human immunodeficiency virus-infected adults. 314 51

With the increased use of immunoglobulin for intravenous use (IGIV) as replacement therapy for patients with primary immunodeficiencies, a natural concern is whether such preparations demonstrate a normal turnover rate with regard to total IgG, individual IgG subclasses, and specific antibody titers. We have conducted such a pharmacokinetic study on a cohort of eight patients with an IGIV preparation, Gammagard. For total IgG, the half-life found was 25.8 days; for IgG1 it was 29.7 days; for IgG2 it was 26.9 days; and for IgG3 it was 15.7 days. The results are similar to those reported for endogeneous IgG. Half-lives for antibodies to S. minnesota (Re 595 mutant), cytomegalovirus, and S. pneumoniae were of the same order of magnitude as that for total IgG. We conclude that this IGIV preparation is catabolized in patients with primary immunodeficiency at a rate similar to that of native IgG in normal individuals.
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PMID:The half-lives of IgG subclasses and specific antibodies in patients with primary immunodeficiency who are receiving intravenously administered immunoglobulin. 318 95

Human immunoglobulin G (IgG) can be divided into four subclasses that are selectively expressed. For instance, carbohydrate antigens preferentially elicit IgG2 antibodies, whereas protein antigens usually elicit IgG1 and IgG3. Elucidating the biological basis of the selective expression of these IgG subclasses is important to our understanding immunodeficiencies and B lymphocyte development. To investigate clinical importance of IgG subclass deficiencies, a sensitive and specific assay has been developed for IgG subclasses using particle concentration fluorescence immunoassay. Preliminary clinical studies have already shown that infection-prone individuals often have selective IgG2 subclass deficiency. Normal levels of IgG2, however, do not rule out an immunodeficiency in the infection-prone individuals because some individuals have normal levels of IgG subclasses and are poorly responsive to antigens of bacteria. Based on animal studies, two contrasting models of B cell development have been advanced. One model of B cell development proposes a single lineage and proposes that a B cell can successively switch and produce any IgG subclass. The other model proposes multiple lineages and proposes that a B cell can express only some IgG subclasses. It has been found by us that anti-PC antibodies are mostly IgG2 with some IgG1, and that the V region of IgG1 anti-PC antibody is different from that of IgG2 antibody. Our finding, therefore, suggests that B cells producing anti-PC antibodies are progeny of not one ancestral B cell that has successively switched, but two independent ancestral B cells. Cellular studies using polyclonal activators also suggest that regulatory mechanisms for IgG1 and IgG3 are different from those of IgG2 and IgG4. Taken together, we favor the multi-lineage model better than the single lineage model of human B cell development.
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PMID:Expression of human IgG subclasses. 330 May 15

Our studies have revealed that patients with Cystic Fibrosis CF who are infected with P. aeruginosa have grossly elevated serum levels of IgG antibodies to the opsonic immunodeterminant, type-specific LPS. Second, this elevation is distributed among all four IgG subclasses, with a significant shift towards IgG3. Third, sera from colonized CF patients shows diminished opsonic capacity, although complement dependent human neutrophil phagocytosis is not notably impaired. Fourth, functional polyclonal or monoclonal antibody opsonins exhibit prozone inhibition of phagocytosis at high concentrations. Fifth, sera from uninfected CF patients have lower levels and proportions of IgG2 antibodies to P. aeruginosa LPS, and higher levels and proportions of IgG4 antibodies, than normal controls. Finally, levels of IgG4 antibodies, but not IgG1, 2, or 3, correlate inversely with opsonic capacity. We therefore make several speculations. High levels of IgG4 antibodies to opsonic immunodeterminants may inhibit normal pulmonary clearance of P. aeruginosa by alveolar macrophages in vivo. Second, high levels of opsonic antibodies may also contribute to the problem in vivo by the phenomenon of prozone inhibition. Third, reduced levels of IgG2 antibodies in uninfected CF patients raises the intriguing possibility of an wider polysaccharide antigen-related isotype-restricted immunodeficiency, with an attempted compensatory shift to IgG4 doomed to failure.
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PMID:The role of IgG subclass antibodies in chronic infection: the case of cystic fibrosis. 336 9


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