[Intrathecal immunoglobulin synthesis evaluation in bone marrow transplantation]. / Avaliação da síntese intratecal de immunoglobulinas no transplante de medula óssea.

The central nervous system involvement in chronic graft versus host disease (GVHD) has been suggested. Chronic GVHD resembles auto immune connective tissue disorders. In order to investigate the immunoglobulin intra blood brain barrier (BBB) synthesis during chronic GVHD, and contribute to understanding the pathophysiology of the disease, we studied 33 patients who underwent allogeneic bone marrow transplants (BMT) from HLA identical related donors. Immunoglobulin intra BBB synthesis was investigated quantitative and qualitatively. The samples were collected pre BMT, pos BMT and during chronic GVHD. There were no evidence of immunoglobulin intra BBB synthesis, and no oligoclonal bands were found. Only isolated cases suggested IgO and IgA intra BBB synthesis, and in one case IgM during GVHD.

[Blood-brain barrier evaluation in bone marrow transplantation]. / Avaliação da barreira hemato-encepfálica no transplante de medula óssea.

The blood-brain barrier (BBB) contributes to the central nervous system (CNS) immunological isolation. BBB has never been studied in patients who developed chronic graft-versus-host disease (GVHD) after allogeneic bone marrow transplants (BMT), from HLA identical related donors. BBB disruption was investigated through the cerebrospinal fluid (CSF) proteins, quantitative and graphically, in order to detect the incidence and possible pathophysiology of the CNS involvement in chronic GVHD. Thirty three CSF and matched serum samples from chronic myeloid leukemia patients were collected pre BMT pos BMT and during chronic GVHD. There was no evidence of BBB disruption in any patient studied.

Dose-response effect of in vivo administration of endotoxin on polymorphonuclear leukocytes oxidative burst.

In vitro, endotoxin primes polymorphonuclear leukocytes (PMNs) to respond with a greater oxidative burst. The purpose of the present study was to investigate the in vivo effect of a wide range of single endotoxin bolus doses using a rat model. PMNs were subsequently challenged in vitro with phorbol ester to produce reactive oxygen intermediates (ROI). Flow cytometric determination of ROI production by large doses induced a decrease in ROI production by the few PMNs that remained in the circulation. By 6 h after injection, ROI production had returned to basal levels after a high dose, and was still increasing after a low dose. Neutropenia occurred immediately after endotoxin injection. After 6 h, PMN counts returned to almost normal levels with a high dose, but rebound neutrophilia occurred with a small dose. In contrast to in vitro studies, in vivo injection showed a response pattern that varied widely with dose and time of observation.

Complement activation in Brazilian pemphigus foliaceus.

Brazilian pemphigus foliaceus is an autoimmune blistering skin disease of man that has a very high incidence in a confined geographical distribution. Rocket immunoelectrophoresis of plasma showed increased levels of complement fragments, C4d and Ba, indicating activation of complement through both the classical and the alternative pathways. Less sensitive methods such as CH50, total C3 and C4 did not demonstrate this activation, and immune complex measurements were within normal range. While complement may not be absolutely necessary for the development of skin lesions, our longitudinal studies show that activation of complement is at its highest during the most active phase of the disease.

Activation of factor B of the alternative pathway of complement. Assessment by rocket immunoelectrophoresis.

During activation of the alternative pathway of complement, Factor B is cleaved into a smaller fragment Ba and a larger fragment Bb. The Ba in plasma was quantitated by one-dimensional rocket immunoelectrophoresis after precipitating plasma B and Bb with 21% polyethyleneglycol. This method was much more sensitive and faster than other technics with which it was compared. Fragment Ba was detected in 22 of 28 rheumatoid arthritis plasma samples and in 12 of 15 systemic lupus erythematous samples but in only 8 of 68 samples obtained from healthy volunteers. The traditional approach of measuring total Factor B for the assessment of activation of the alternative pathway showed values that were even higher than normal in these diseases. The measurement of plasma Ba promises to be a valuable means of assessment of the activation of Factor B and the alternative pathway of complement in clinical disorders.

Native and non-native conformation-specific antibodies directed to the loop region of hen egg-white lysozyme.

Two types of antibodies were differentiated in conventional guinea pig anti-hen egg-white lysozyme (HEL) antisera. The specificities of both antibodies were directed to the loop I region (mainly directed to Cys64--Cys80 loop) but the antibodies were distinct in respect of reactivities with native HEL. One type of antibody reacted with HEL and loop-peptides of HEL but not with the completely reduced and carboxymethylated form of loop-peptides (native conformation specific antibody: NC-Ab). On the other hand, the other type of antibody did not react with HEL but reacted with loop-peptides and also with the completely reduced and carboxymethylated form of loop-peptides (non-native conformation specific antibody: NNC-Ab). The percentage of NNC-Ab in loop I reactive antibody fraction from pooled guinea pig anti-HEL antisera obtained by two different immunization methods was about 25%. Since the affinities of the NNC-Ab to loop-related peptides were higher by one order of magnitude than those of the NC-Ab to the same peptides, care is necessary in evaluating antigenic determinants in native protein. The immunization of guinea pigs with Ploop I . II [sequence 57-107 (Cys64-Cys80, Cys76-Cys94)] evoked an antibody population having specificity similar to but not identical with that of the NNC-Ab type anti-loop I antibody in conventional anti-HEL antisera.