Clinical factors relating to the presence of serum anti-GM1 and GD1b antibodies in demyelinating neuropathy--study using a multivariate analysis

We studied clinical factors relating to the presence of serum anti-GM1 and GD1b antibodies in patients with demyelinating neuropathy using a multivariate analysis. Sera were obtained from 46 patients with chronic inflammatory demyelinating polyneuropathy (CIDP) and 33 with Guillain-Barré syndrome (GBS) and kept frozen at -20 degrees C until use. Anti-GM1 and GD1b IgM and IgG antibodies were measured by ELISA at serum dilution of 1:100 and considered to be positive when those values were more than the cut off values determined by means and standard deviations in 35 normal controls. Age, sex, duration, prodromal disease, neurological findings, concentration of CSF protein, nerve conduction, treatment, and outcome were investigated in all patients retrospectively. Multivariate logistic models using all those characteristics were used to clarify the clinical factors relating to the presence of anti-GM1 and GD1b antibodies. In CIDP, anti-GM1 antibodies associated with or without anti-GD1b antibodies were frequently seen in patients with motor dominant neuropathy than those with sensory dominant neuropathy (P = 0.007, odds ratio = 11.6). There was significant difference in anti-GM1 IgM antibodies (P = 0.003, odds ratio = 22.2), but no difference in IgG antibodies. Anti-GM1 antibodies were observed 5 (IgM, 5; IgG, 2) of 7 patients with pure motor neuropathy, 9 (IgM, 8; IgG, 4) of 17 with motor dominant neuropathy, 5 (IgM, 2; IgG, 3) of 16 with sensori-motor neuropathy, and none of 6 with sensory dominant neuropathy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Anti-GD1a ganglioside antibodies in peripheral motor syndromes

High titers of anti-GD1a antibodies have been found in patients with Guillain-Barre syndrome or motor neuropathy. To determine the possible diagnostic relevance of these antibodies, we measured serum anti-GD1a IgG and IgM antibodies by enzyme-linked immunosorbent assay in 195 patients with different motor syndromes and in 335 control subjects. Moderately high antibody titers (1/1,280-1/5,120) were occasionally found in patients with chronic inflammatory demyelinating polyneuropathy (5%), multifocal motor neuropathy (18%), lower motor neuron disease (3.8%), or amyotrophic lateral sclerosis (1.8%) and in immunological control subjects (1.2%), while titers of 1/20,480 or higher were only found in 2 patients with Guillain-Barre syndrome (IgG in both) and 2 with motor neuropathy and IgM lambda monoclonal gammopathy improving with immunotherapy. In both motor neuropathy patients and the Guillain-Barre syndrome patient who were retested during recovery, anti-GD1a titers decreased concomitantly with clinical improvement. High anti-GD1a antibody titers may be found in several motor syndromes but only markedly increased anti-GD1a titers are strictly associated with potentially treatable dysimmune neuropathies.     

Cholinergic neuron-specific ganglioside GQ1b alpha a possible target molecule for serum IgM antibodies in some patients with sensory ataxia

In neurological diseases the presence of certain anti-glycosphingolipid antibody species is associated with the clinical features. We recently isolated the novel cholinergic neuron-specific gangliosides GQ1b alpha and GT1a alpha from bovine brain. A monoclonal antibody specific for GQ1b alpha and GT1a alpha reacted strongly with the dorsal born of human spinal cord but not with human motor neurons. We investigated the serum antibodies to these minor gangliosides in a number of neurologic diseases and found that 4 patients with sensory ataxic neuropathy had a remarkably high IgM anti-GQ1b alpha antibody titer. GQ1b alpha may be a target molecule for serum IgM antibodies in some patients with sensory ataxic neuropathy.     

Anticonvulsant and glutamate release-inhibiting properties of the highly potent metabotropic glutamate receptor agonist (2S,2''R, 3''R)-2-(2'',3''-dicarboxycyclopropyl)glycine (DCG-IV)

IgA has an important function in the gastrointestinal immune system. We investigated IgA anti-ganglioside antibodies in Guillain-Barré syndrome (GBS) and Fisher's syndrome (FS) subsequent to Campylobacter jejuni enteritis. In previous studies, serological diagnosis of C. jejuni infection was based on the detection of IgG, IgA, and IgM anti-C. jejuni antibodies. Our study, however, showed that the detection of IgG anti-C. jejuni antibody alone was sufficient for the serological diagnosis of antecedent C. jejuni enteritis in GBS and FS, when the cut-off level was defined for results of sera from C. jejuni-isolated patients. Serological evidence of C. jejuni infection was found in 62 (31%) of 201 GBS patients and 12 (18%) of 65 FS patients. IgA anti-GMI antibody was detected in sera from 33 (16%) of the GBS patients, 1 (2%) of the FS patients, and none of the 46 normal control subjects. IgA anti-GM1 antibody titers were significantly higher in the GBS patients with positive C. jejuni serology than in those with negative serology (P < 0.0001) or the FS patients with positive C. jejuni serology (P = 0.007). IgA anti-GQ1b antibody was detected in sera from 18 (28%) of the FS patients, 9 (4%) of the GBS patients, and none of the normal control subjects. FS patients with positive C. jejuni serology had significantly higher titers of IgA anti-GQ1b antibody than those with negative serology (P = 0.01) or the GBS patients with positive C. jejuni serology (P < 0.0001). We conclude that anti-GM1 and anti-GQ1b IgA antibodies are closely associated with antecedent C. jejuni enteritis in GBS and FS, respectively.     

Paraproteinaemic neuropathies

Paraproteinaemia and neuropathy are each relatively frequent and may be associated by chance. However, a number of significant relationships have to be ruled out in the differential diagnosis. Malignant gammopathy should be excluded: multiple myeloma can lead to compression of the spinal cord or cauda equina; primary amyloidosis is occasionally involved; the rare but intriguing POEMS syndrome, consisting of polyneuropathy, organomegaly, endocrinopathy, M-protein and skin changes, usually accompanies osteosclerotic myeloma. It can be associated with angio-follicular lymph node hyperplasia and needs to be recognized because radioablative therapy is curative. The 'benign' monoclonal gammopathies of undetermined significance, known as MGUS, are much more frequent. There is an IgM MGUS group with predominantly distal sensorimotor demyelinating polyneuropathy and another rather heterogeneous group with IgG or IgA MGUS and a tendency to a favourable response to plasmapheresis. The role of the monoclonal IgG and IgA antibodies is unclear. This chapter has focused on the pathogenetic mechanisms of neuropathies associated with IgM MGUS. In the majority of cases, monoclonal autoantibodies specific for particular carbohydrate epitopes bind to myelin and are now recognized as the primary cause of the disease manifestations, including widening of the myelin lamellae. While the autoantibodies have been shown to bind complement, the presence of inhibitors is invoked to explain the absence of acute inflammatory changes. The epitopes recognized with the highest affinity by the auto-antibodies are present on the myelin-associated glycoprotein (MAG) and could interfere with cell adhesion and cellular signally processes. In addition, binding to antigenically similar glycoproteins, such as PO, PMP-22 and some acidic glycolipids, may be a contributory factor. It is generally accepted that the anti-MAG autoantibodies are inducing a progressive demyelinating polyneuropathy by modifying axon-Schwann cell interactions.     

Sulphatide antigen in islets of Langerhans and in diabetic glomeruli, and anti-sulphatide antibodies in type 1 diabetes mellitus

Clinical coincidence between diabetes and neurological disorders, and sharing of antigen determinants between islets of Langerhans and neural tissue, has been suggested. Sulphatide is a neural epitope which can be visualized with a monoclonal antibody Sulph I. Different tissues were examined by immunohistological methods. Sulphatide and anti-sulphatide antibodies were determined by thin-layer chromatographic techniques. IgG was isolated using protein A columns. A specific staining by Sulph I was found of rat islets, assigned to the secretory granules of both alpha and beta cells. No labelling of the exocrine tissue or other body tissues was seen, except for nerve and kidney structures. The latter showed staining of the distal tubules and, in addition, but only in the diabetic kidney, of glomeruli located in the subendothelial area in the capillary loops and the mesangial space. Sera from 38% of 40 spontaneously diabetic BB rats displayed anti-sulphatide antibodies, mainly IgG, whereas all 30 control Lewis rats were negative. Most recently we have demonstrated anti-sulphatide antibodies in 88% of 57 patients with newly diagnosed Type 1 diabetes (titres of > 1:400); all 135 healthy control persons were negative. The sulphatide antibody reactivity was present in the IgG fractions of the patients' sera. Thus, sulphatide is demonstrated in islets of Langerhans and in kidney related to the diabetic lesion, and, furthermore, anti-sulphatide antibodies exist in Type 1 diabetes mellitus.     

Treatment of immune deficient neuropathies with intravenous polyvalent immunoglobulins. An open study of 16 cases

Between June 1989 and February 1992, in an open controlled study 16 patients with various types of polyneuropathy were treated with high-dose intravenous immunoglobulins (IgIV). Every month during 3 months, each patient received three courses of IgIV in doses of 0.4 g/kg/day during 5 successive days. The trial was discontinued in case of no response or if the neuropathy was considered as being in remission. In the other cases, at most one course of IgIV was given once a month if there was significant improvement (assessed by previously published clinical functional scales, electrophysiological examinations and titers of specific antibodies), or spaced at intervals which varied according to each patient, and sometimes in low doses. Results: 1) A first group of 6 patients had chronic demyelinating polyneuropathy with severe motor disability. The first infusions of IgIV resulted, in 4/6 cases, in a dramatic improvement which lasted under regularly spaced courses in lower doses. 2) Four patients had chronic neuropathy associated with monoclonal IgM gammopathy of undetermined significance (3 had anti-MAG and anti-SPG antibodies, and 1 had anti-GD1a and GD1b antibodies) and had not been improved by the usual immunosuppressive treatments. In 1 case the IgIV treatment had to be discontinued because of skin allergy. In the remaining 3 patients the clinical disorders (mainly the sensory ones) were reduced, but no significant improvement of neurophysiological or immunological data was observed. 3) Three patients had a purely multifocal motor neuropathy with persistent conduction blocks at EMG and high titers of anti-GM1 antibodies in 2/3 cases.(ABSTRACT TRUNCATED AT 250 WORDS)     

Anti-ganglioside antibodies in patients with rheumatoid arthritis complicated by peripheral neuropathy

Gangliosides are a diverse class of glycolipids found in the plasma membrane of mammalian cells and are particularly abundant in cells of the nervous system. Serum antibodies to gangliosides have been detected in various neurological disorders with some evidence that they play a pathogenic role. In this study, we have investigated whether anti-ganglioside antibodies were elevated in a group of patients with rheumatoid arthritis (RA) who developed peripheral neuropathy (PN). An ELISA technique was used to test sera from 28 patients with RA and PN. 38 RA patients without PN and 20 normal controls for the presence of IgG and IgM anti-GM1 and sulphatide antibodies. The patients with RA and PN had higher pain scores (P < 0.005), more extra-articular features (P < 0.05), higher erosive scores (P < 0.0001), lower haemoglobin (P < 0.005), higher ESR (P < 0.001) and were more often on disease-modifying drugs (P < 0.05). Twelve RA patients with PN (43%), but only two RA controls (5%), had positive titres against one or more gangliosides (P < 0.001). The neurologic disability score (NDS) correlated with RA duration (P < 0.05), and with levels of IgM anti-GM1 (P < 0.001) and IgM anti-sulphatide (P < 0.05) antibodies. We conclude that PN is more common in patients with severe rheumatoid disease, and a significant proportion have elevated levels of anti-ganglioside antibodies.     

Trypanosoma cruzi infection in mice induces a polyisotypic hypergammaglobulinaemia and parasite-specific response involving high IgG2a concentrations and highly avid IgG1 antibodies

Trypanosoma cruzi infection in BALB/c mice induced a reversible polyisotypic hypergammaglobulinaemia, with particularly high levels of IgG2a, IgM and IgE. Hypergammaglobulinaemia started during the acute phase of infection and persisted during chronic disease until 11-13 weeks post-infection (w.p.i.), when immunoglobulin levels, with the exception of IgE, returned near normal values. Parasite-specific antibodies counted for 14 to 23% of gammaglobulinaemia, in acute and chronic infection respectively. The titres of IgM antibodies rose from two w.p.i. IgA, IgE and IgG subclass antibodies built up gradually over the time of parasite clearance (i.e., between three and six w.p.i.). All antibody isotypes, including IgM reached significant and stable titres throughout chronic infection. IgG2a, IgG1 and IgM antibodies had constantly higher titres than the other antibody isotypes. The dominance of IgG2a antibodies was due to their high plasma concentrations, around 70% of all antibodies available in the chronic infection. IgG1 had the highest functional avidity, whereas its concentration corresponded to only 10% of the whole antibody fraction. These results indicate that T. cruzi infection in mice induces a polyisotypic humoral immune response, dominated by some antibody isotypes, with major differences in concentrations and functional avidities. This could be of crucial importance in determining the outcome of infection.     

Serum antibodies to heparan sulfate glycosaminoglycans in Guillain-Barré syndrome and other demyelinating polyneuropathies

We tested for serum antibodies to glycosaminoglycans (GAGs), including heparan sulfate, in patients with Guillain-Barré syndrome (GBS) and other disorders. We used ELISA methods that optimize immunoglobulin binding to carbohydrate antigens to measure serum antibodies to heparan sulfate GAGs in GBS, and control neuromuscular and immune disorders. We found serum IgM or IgG antibodies to heparan sulfate GAGs in 34% of patients with GBS. Serum IgM binding to heparan sulfate GAGs was also found in some chronic demyelinating polyneuropathies, with the highest frequency (33%) in patients with IgM anti-MAG M-proteins. Antibodies to heparan sulfate GAGs were rare (1%) in control serums from patients with other disorders. This result is the first demonstration of high titer serum antibodies to a specific antigen in a substantial group of, and with some specificity for, patients with the classically described GBS syndrome of acute-onset, motor-sensory polyneuropathy with demyelinating features.     

An analysis of the central pathway of vestibulo-sympathetic responses

The sera of 159 patients with monoclonal gammopathies were examined for the presence of anti-thyroglobulin (Tg) activity. An enzyme-linked immunosorbent assay was employed. Thirty-one (19.5%) sera were found to bind Tg. The activity against Tg was further confirmed by using purified immunoglobulins and employing competition assays. The anti-Tg antibodies were found in the sera of patients with IgG, IgM and IgA gammopathies. Anti-Tg antibodies were more frequent among patients with IgG gammopathy. Autoantibodies to Tg are found in patients with Hashimoto's thyroiditis, Graves' disease and occasionally in patients with thyroid carcinoma. Natural autoantibodies directed against human Tg have been detected, as well, in healthy subjects. None of the patients in the present study whose serum was found to contain high titers of anti-Tg human monoclonal antibodies had any clinical or biochemical evidence of thyroid disease. Our results of a high incidence of anti-Tg activity in the sera of patients with monoclonal gammopathies support previous reports of autoantibody properties characteristic of these immunoglobulins.     

Myelin modifications in 8 cases of peripheral neuropathy with Waldenstr?m's macroglobulinemia and anti-MAG activity

Characteristic myelin modifications in patients with IgM monoclonal gammopathy and anti-MAG activity have mainly been studied in cases of undetermined significance, but also exist in cases with indolent Waldenstr?m's macroglobulinemia, i.e., when lymphoplasmocytic infiltration in bone marrow is 15% or more, without any visceral involvement. Since 1983, the authors have examined nerve biopsies from 8 cases with Waldenstr?m's macroglobulinelia by direct immunofluorescence examination on frozen sections and ultrastructural examination. At direct immunofluorescence, fixation of anti-IgM serum on myelinated fibers was present in 7 cases. At ultrastructural examination, a widening of some myelin lamellae at the periphery of a few fibers was visible in 8 cases. A few fibers with hypermyelination were present in 5 cases. In 2 of these 5 cases widening of some myelin lamellae was present in numerous fibers, 88% in one of them. Frequently, there was a major widening of some myelin lamellae with dilated lamellae present in the inner part of the myelin sheath. Certain lamellae were more dilated, up to 50 nm. Occasionally, enlarged lamellae were not compacted with each other. The authors also examined nerve biopsies from 36 patients with IgM monoclonal gammopathy of undetermined significance and anti-MAG activity, but found only one case with major widening of some myelin lamellae. Five other cases with major widening of some myelin lamellae, 4 Waldenstr?m's macroglobulinemia and 1 IgM monoclonal gammopathy of undetermined significance, have been reported. Given that demyelinating neuropathies are far more numerous in cases with IgM monoclonal gammopathy of undetermined significance, it is likely that cases of indolent Waldenstr?m's macroglobulinemia are prone to develop major myelin modifications, possibly due to another mechanism, added to the classic anti-MAG activity.     

Predictive value of Toxoplasma gondii antibody titres on the occurrence of toxoplasmic encephalitis in HIV-infected patients. ANRS 005/ACTG 154 Trial Group

OBJECTIVE: To study the predictive value of anti-Toxoplasma gondii antibody titres for the occurrence of toxoplasmic encephalitis (TE) in HIV-infected patients. METHODS: Data from the placebo arm of a trial of primary prophylaxis for TE (ANRS 005/ACTG 154) were analysed. Patients included had CD4+ cell counts < 200 x 10(6)/l and a positive Toxoplasma serology. Immunoglobulin (Ig) G and IgM Toxoplasma antibody titres at entry were retrospectively determined by enzyme-linked immunosorbent assay and agglutination on serum samples in a single laboratory. Incidence of TE was estimated by Kaplan-Meier method and a Cox model was used to study the predictive value of antibody titres, adjusted for other covariates. RESULTS: All 164 patients studied were positive for IgG antibodies and one had IgM antibodies. After a mean follow-up of 16 months, 31 cases of TE were documented. One-year incidence of TE was significantly higher in patients with IgG titres > or = 150 IU/ml (23.7%) than in patients with titres < 150 IU/ml (7.7%; relative risk, 3.1; P < 0.003). IgG titres remained significantly associated with the occurrence of TE (relative risk, 3.3; P < 0.005) in the Cox model. Predictive value of IgG titres did not differ according to baseline CD4+ cell counts. CONCLUSIONS: In patients with CD4+ cell counts < 200 x 10(6)/l, IgG anti-Toxoplasma antibody titre is a prognostic factor of occurrence of TE, with a higher risk for titres > or = 150 IU/ml. This finding should reinforce the recommendation of specific prophylaxis in these patients.     

Peripheral neuropathies associated with monoclonal proteins

Peripheral neuropathies associated with monoclonal proteins have received considerable attention as a clinically important group of chronic late-onset neuropathies. When a monoclonal protein is found in patients with peripheral neuropathy of unknown cause, as occurs in 10% of such cases, usually no associated disease is discovered; hence MGUS. Less often, disorders such as multiple myeloma, AL amyloidosis, Waldenstr?m's macroglobulinemia, osteosclerotic myeloma, and lymphoma are found. Demyelinating neuropathies associated with MGUS of all classes, but particularly IgM, Waldenstr?m's macroglobulinemia, and osteosclerotic myeloma typically follow an indolently progressive course, and frequently respond to treatments aimed at interfering with putative underlying immune mechanisms. By contrast, axonal neuropathies associated with MGUS, multiple myeloma, and AL amyloidosis have generally shown no response to therapy. Recently, IgM monoclonal and polyclonal antibodies directed against human peripheral nerve antigens including MAG and various glycolipids such as GM1 ganglioside have been found in patients with specific neuropathy syndromes. Anti-MAG antibodies occur in predominantly sensory demyelinating neuropathies, whereas elevated titers of anti-GM1 ganglioside antibodies are associated with lower motor neuron syndromes with multifocal motor conduction block. Although the evidence for autoimmune mechanisms in some monoclonal protein-associated neuropathies is mounting, a causal connection between monoclonal proteins and these neurologic syndromes has yet to be established.     

Chlamydia and the Curtis-Fitz-Hugh syndrome

Ten women with acute right upper-quadrant abdominal pain but negative results for biliary investigations had a current or past history of pelvic inflammatory disease. A diagnosis of the Curtis-Fitz-Hugh syndrome was made and was confirmed in five patients by laparoscopy. Neisseria gonorrhoeae was not isolated from the cervical and urethral swabbings of seven patients tested. Chlamydia trachomatis was isolated from the endocervical canal in one of six patients examined. Of sera from nine patients tested by a micro-immunofluorescence test, nine and six samples respectively showed type-specific IgG and IgM antibodies against C trachomatis serotypes D-K. Type-specific IgG and IgA antibodies were also detected in the cervical and urethral discharge of two out of five patients and in the peritoneal aspirate of two. The presence of high titres of IgG or IgM in sera and IgG or IgA in the local discharges of our patients suggests that C trachomatis was probably the cause of the CFH syndrome.     

Detection of isotype-specific autoantibodies to calpastatin in sera from patients with rheumatic diseases using heat-treated HeLa cell extract as an antigen source for immunoblotting

To detect immunoglobulin isotype-specific autoantibodies to native human calpastatin in patients with rheumatic diseases, we performed immunoblot analysis using the heated HeLa cell extracts to enrich heat-resistant calpastatin. The calpastatin molecule that was apparently migrated to 110 kD by SDS-PAGE was confirmed to react with monoclonal anti-human calpastatin antibody in immunoblotting. IgG antibodies to calpastatin were detected in 22 of 48 sera (46%) from patients with RA, whereas only 20% (5/25), 11% (2/19) and 13% (2/15) of sera from SLE, SSc and PM/DM had IgG anti-calpastatin antibodies, respectively. IgM antibodies were also found in 40% (19/48) of RA and 12% (3/25) of SLE patients but not detected in sera from patients with other rheumatic diseases. IgA antibodies were found in only one RA and one SLE serum. In RA, 7 of 48 sera (15%) had IgM antibodies alone, but all SLE sera with IgM antibodies had IgG antibodies. Thus, anti-calpastatin autoantibodies were detected by using the native human calpastatin. Although these autoantibodies were found in patients with various rheumatic diseases, they were present in RA patients at the highest frequency. In particular, the presence of IgM antibodies appeared to be more specific in RA patients.     

Combined thallium-201 myocardial with technetium-99m-HMPAO brain SPECT: myocardial ischemia induced by acetazolamide in severe coronary artery disease

IgM anti-myelin-associated glycoprotein (anti-MAG)/sulfated glucuronyl paragloboside (SGPG) antibody is found in some patients with chronic polyneuropathy (CP). An antigen-driven process is considered to induce this autoantibody, but the agent has yet to be identified. It has been reported that sera from cytomegalovirus (CMV)-infected patients contained anti-SGPG antibody. To clarify the mechanism of the production of the anti-MAG/SGPG antibody, we investigated CMV DNA in sera from 26 patients with IgM anti-MAG/SGPG antibody-positive CP. Twenty-three (88%) had CMV DNA. The positive frequency was significantly higher than the frequencies in sera from patients with IgM anti-MAG/SGPG-negative CP, the other disease controls, and the normal control subjects. There were no statistical differences in the frequencies of Epstein-Barr virus DNA between anti-MAG/SGPG-positive and anti-MAG/SGPG-negative CP and between anti-MAG/SGPG-positive CP and each disease control. Moreover, no herpes simplex virus 1 DNA was detected in the sera from patients with anti-MAG/SGPG-positive CP. The strong correlation of anti-MAG/SGPG-positive CP with the presence of serum CMV DNA suggests that CMV infection induces the IgM anti-MAG/SGPG antibody.     

Serologic responses of young colostrum fed dairy calves to antigens of Pasteurella haemolytica A1

The potential and limitations of early calfhood vaccination to induce active immunity to Pasteurella haemolytica A1 in conventional colostrum fed calves were investigated. Holstein dairy calves (n = 29) were vaccinated at 2 and 4 weeks of age, or at 6 and 8 weeks of age with a commercial culture supernatant vaccine (Presponse, Langford Inc., Guelph, Ont., Canada), or remained unvaccinated as controls. Serum antibody titres were measured using an indirect bacterial agglutination assay, a leukotoxin neutralization assay, and enzyme immunoassays for antibodies of the IgM, IgG1, and IgG2 isotypes binding purified capsular polysaccharide of P. haemolytica A1. Seroconversion (fourfold or greater increase in serum antibody titre) rates were compared using Fisher's exact test. The effects of passive antibody titres and age on response to vaccination were assessed by linear modelling. Vaccination at 2 and 4 weeks of age was associated with 40%, and 0% of calves seroconverting on the basis of agglutinating antibody titres, and leukotoxin neutralizing titres respectively, and 50%, 0%, and 0% seroconverting on the basis of IgM, IgG1 and IgG2 antibodies to capsular polysaccharide, respectively. Agglutinating antibody responses were not related to prevaccination antibody titres, or to age at vaccination. Higher responses (p = 0.08) to leukotoxin were observed in older calves (after taking differences in prevaccination titres into account). Statistical analyses of responses to capsular polysaccharide among calves with comparable prevaccination IgG1 antibody titres revealed significantly higher IgM, IgG1 and IgG2 responses in older calves. Rising titres of IgM antibodies in nonvaccinated calves after 5 weeks of age suggest natural exposure to P. haemolytica A1 or antigens which result in serologic cross-reactions as a means of priming immune responses.     

Monoclonal and polyclonal antibodies to chicken immunoglobulin isotypes specifically detect turkey immunoglobulin isotypes

Turkey immunoglobulin (Ig) isotypes IgG and IgM were isolated from blood and IgA was isolated from bile. Isolation was accomplished by gel filtration of the ammonium sulphate cut on Sephacryl S-200. Using immunoelectrophoresis and indirect ELISA, the cross-reactivity between antibodies, of monoclonal and polyclonal origin, specific for the Ig isotypes of chicken, and the purified turkey Ig isotypes was evaluated. Commercially available polyclonal antibodies, anti-chicken/IgA (alpha-chain specific, affinity purified), anti-chicken/IgG (Fc-fragment specific) and anti-chicken/IgM (mu-chain specific) showed an interspecies cross-reactivity with the corresponding turkey Ig isotypes. The monoclonal antibody (MAb) AV-G3 specifically detected turkey IgG, whereas MAb M1 reacted exclusively with turkey IgM. This panel of anti-immunoglobulins represents a useful tool for examining the humoral immune responses of turkeys.     

Serological follow-up of patients with paracoccidioidomycosis treated with itraconazole using Dot-blot, ELISA and western-blot

Twenty-seven mycologically proven cases of paracoccidioidomycosis (PCM) were treated with itraconazole (100-200 mg/day in month 1 and 100 mg/day until month 6-8) and evaluated clinically and serologically, up to 3.5 years post-therapy, using Dot-blot and ELISA for measuring the titers of IgG, IgA and IgM anti-P.brasiliensis antibodies and Western-blot for determining IgG, IgA and IgM antibodies against the antigen components of the fungus. Before treatment, 81.5% (Dot-blot) and 84% (ELISA) of the patients presented elevated IgG anti-P.brasiliensis antibody titers which dropped slightly with treatment. On the other hand, the percentages of pre-treatment high-titered sera for IgA and IgM anti-P.brasiliensis were lower (51.9% and 51.8%: Dot-blot; 16.5 and 36%: ELISA, respectively) but the titers tended to become negative more frequently with treatment. Prior to treatment, the percentages of positivity for IgG, IgA and IgM anti-P.brasiliensis antibodies in Western-blot were 96%, 20.8% and 41.6%, respectively. Antigens with molecular weights varying from 16-78 kDa, from 21-76 kDa and from 27-78 kDa were reactive for IgG, IgA and IgM antibodies, respectively. The most frequently reactive antigenic components had molecular weights of 27, 33 and 43 kDa for IgG, and 70 for IgA and IgM antibodies. During the period of study, the patients responded well to treatment. The present data confirm the diversity and complexity of the humoral response in PCM, and the importance of utilizing different serological tests to detect IgG, IgA and IgM anti-P. brasiliensis antibodies.