Search PubMedSearch

PubMed · 8770715

Immunologic rebound.

Abstract

Evidence for accelerated specific antibody (Ab) rebound or overshoot after single or multiple therapeutic plasmapheresis (TP) is fragmentary but suggested by both clinical and experimental evidence. In vitro studies showing increased peripheral blood lymphocyte turnover and total immunoglobulin production after a series of TP without immunosuppression may signify a generalized immunostimulation through removal of regulatory molecules by TP. It is known that IgG class Ab can down regulate B cells by cross linkage of their Ag and Fc receptors. Cyclophosphamide and other cytotoxic immunosuppressive agents effectively delete proliferating lymphocytes. TP could particularly foster deletion of lymphocytes actively mediating autoimmunity, since they would be more readily stimulated to proliferation by removal of Ab or other inhibitory factors than the generally resting normal immune system. This is supported by a relatively greater reduction of autoantibody levels than total immunoglobulin after treatment with TP and cytotoxic immunosuppressives.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

P C Dau. 1995. Immunologic rebound.. https://doi.org/10.1002/jca.2920100410

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Gene silencing results in instability of antibody production in transgenic plants.

The stability of antibody and Fab expression was assessed in five different homozygous transgenic Arabidopsis lines. Each of these lines showed silencing of the transgenes that encode the antibody polypeptides, leading to instability of antibody production. However, each line had a different and specific instability profile. The characteristic variation in the level of antibody accumulation in each line as a function of developmental stage indicated that the T-DNA integration pattern played a role in triggering silencing, and also that the history and the integration position of simple transgene loci can influence the susceptibility to epigenetic silencing. In different lines with low antibody accumulation levels, methylation was found either in the promoter alone, in both the promoter and the transcribed region, in the transcribed region only, or in the transcribed region and downstream sequences. In conclusion, our data suggest that epigenetic effects result in different transgene expression profiles in each of the five Arabidopsis lines analyzed.

Antibody Formation

IDDM patients neither show humoral reactivities against endogenous retroviral envelope protein nor do they differ in retroviral mRNA expression from healthy relatives or normal individuals.

Recently, human endogenous retrovirus type K (HERV-K [IDDMK(1,2)22]) was isolated from an IDDM patient's beta-cell supernatant and shown to be implicated in expression as a superantigen. Furthermore, HERV-K RNA was found in plasma samples from newly diagnosed patients but not in those from healthy control subjects. We had earlier identified the presence of a HERV-K long terminal repeat element of the HLA DQ gene (DQ-LTR) to be positively associated with IDDM, which led us to investigate whether DQ-LTR is related to transcription of the putative retroviral superantigen. Additionally, we sought immunological evidence to determine whether those retroviral antigens could evoke an antibody response. Patients with IDDM (n = 14), Hashimoto's thyroiditits (n = 5), and Graves' disease (n = 12), as well as healthy control subjects (n = 12), were investigated, as were four nuclear families of Graves' disease patients and two of IDDM patients. RNA was isolated from plasma and peripheral blood lymphocytes and subjected to reverse transcription-polymerase chain reaction for transcripts of the env region of the HERV-K (IDDMK(1,2)22) sequence. We identified env transcripts in both plasma and peripheral blood lymphocytes in all individuals studied: patients with recent-onset or long-standing IDDM, their relatives, and healthy control subjects, as well as patients with thyroid autoimmune disorders. Furthermore, we screened the sera of patients (n = 62) and control subjects (n = 35) for evidence of humoral immunity against HERV-K by Western blot specific for the ENV protein. Similar frequencies of antibody-positives were observed both in patients with IDDM (29%) and in healthy control subjects (26%). We conclude that neither the ubiquitous HERV-K transcripts nor the comparable percentage of ENV protein antibodies are associated with IDDM. An earlier, presymptomatic antibody response against HERV-K (IDDMK(1,22)22) ENV cannot be ruled out. However, the superantigen hypothesis of an endogenous retrovirus in beta-cell autoimmunity awaits confirmation.

Antibody Formation