[Contribution of CSF analysis to diagnosis and follow-up of tuberculous meningitis]. / Contribution de l'analyse du LCR au diagnostic et au suivi évolutif d'une méningite tuberculeuse.

We report the case of a patient who was admitted to the hospital because of language and mental confusion. His initial lumbar puncture revealed 193 leukocytes per mm3 mostly lymphocytes (95%), no red blood cells, high protein content (1.20 g/L) and normal glucose level. The antibiotic therapy by amoxicilline and aciclovir during 6 days led to complete clinical recovery in a week. A CT scan of the cerebrum showed no abnormalities, nor did chest radiography. Twelve days after discharge, the patient was rehospitalized because of a meningitis syndrome. On lumbar puncture, the CSF analysis revealed 280 leukocytes/mm3, 56% lymphocytes, 10% monocytes and 34% polymorphonuclear cells. CSF chemistry showed a protein level of 3.54 g/L, and a glucose level depressed at 0.9 mmol/L. Because of the clinical symptoms and CSF abnormalities, the patient received aciclovir, amoxicilline vancomycine, isoniazide, rifampicine, pyrazinamide and ethambutol. Screening for infections gave negative results until the 37th day, when the diagnosis of tuberculous meningitis was confirmed by the isolation of Mycobacterium tuberculosis in the repetitive CSF. Antituberculous therapy was expanded. According the Reiber diagrams, intrathecal IgG synthesis was negative at day 25, day 37, month 4, month 9, month 17. Intrathecal IgM synthesis was elevated at day 12 and day 25 and intrathecal IgA synthesis at day 25. Improvement of the patient's conditions by tuberculosis treatment was obtained in 17 months. Cerebrospinal fluid analysis has been the basis for the diagnosis and follow-up of tuberculous meningitidis.

[CSF: diagnosis of neurosyphilis in a patient hospitalized for an acute brain stroke]. / LCR : diagnostic d'une neurosyphilis lors d'une hospitalisation pour un accident vasculaire cérébral.

We report the case of a sixty-eight years old patient, who was admitted to the emergency for paresthesis associated with dysarthra and speech complaints. Neuroimaging revealed the presence of stenosis caused by arteritis. The notion of history of syphilis infection led to diagnosis of neurosyphilis. Diagnosis is difficult due to its clinical polymorphism and requires using several tests in the cerebrospinal fluid (CSF) because infection involving the central nervous system. Neurosyphilis is diagnosed by finding elevated cell count (80 leukocytes/mm3), high protein level (1.07 g/L) and positive IgG oligoclonal bands. In addition CSF and blood should be titrated with the VDRL and TPHA tests which are difficult to interpret. The diagnosis of active neuro-syphilis requires positive, non specific and specific inflammatory tests.

[Diagnostic value of the anti-IgM SGPG Elisa (Bühlmann laboratories AG) in 147 sera with a monoclonal IgM anti-MAG/SGPG antibody-associated neuropathy]. / Contribution des autoanticorps IgM anti-SGPG par Elisa Bühlmann au diagnostic de 147 neuropathies périphériques démyélinisantes associées à une IgM monoclonale.

Binding of monoclonal IgM antibodies in serum to antigens of the peripheral nervous system such as MAG and SG(L)PG was measured by various non standardised methods. In this study we evaluated a new commercially available IgM anti-SGPG ELISA (Bühlmann Laboratories AG, Switzerland). The results were compared with three different markers and methods: (1) an in-house thin-layer overlay chromatography for IgM reactivity against sulfated glucuronosyl paragloboside (SGPG) antibodies (gold standard), (2) an indirect immunofluorescent assay for detecting IgM antibodies against myelin, and (3) IgM anti-MAG antibodies, a commercially available Kit based on ELISA technology, manufactured by Bühlmann Laboratories AG. 147 patient sera with anti-MAG/SGPG neuropathy and 121 control sera from patients with peripheral neuropathy were analysed. The anti-SGPG autoantibody ELISA turned out to be a very reliable commercially available test with no technical difficulties and both, excellent sensitivity (0.98), and specificity (0.98) for detecting MAG/SGPG antibody-mediated demyelinating neuropathies. Anti-SGPG antibody titers have pratical implications for both, management and follow-up of neuropathies treated with rituximab.

[Polyneuropathy involving cranial nerves associated with monoclonal IgM antibodies with anti-MAG/SGPG/SGPLG/sulfatides activity]. / Une polyneuropathie avec atteinte des nerfs crâniens associée à une IgM monoclonale à activité anti-MAG/SGPG/SGPLG/sulfatides.

INTRODUCTION: A typically distal and symmetrical, slowly progressive sensorimotor demyelinating neuropathy is caused by monoclonal IgM against myelin-associated glycoprotein (MAG) and SGPG, SGLPG glycolipids in the context of a benign IgM paraproteinemia. We studied a patient with a neuropathy that fulfilled the diagnostic criteria for CIDP in whom IgM kappa anti-MAG/SGPG/SGLPG were detected. OBSERVATION: The patient was a 57-year-old man who had developed a slowly progressive distal sensorimotor neuropathy, involving the lower then upper limbs, with cranial nerves palsies (oro-pharyngo-laryngo territory). ENMG showed a demyelinating neuropathy with a disproportionate slowing of conduction in distal segments of motor and axonal features in the lower limbs. The first routine laboratory analysis revealed negative or normal findings. Several serum protein electrophoreses were normal. The third cerebrospinal fluid examination demonstrated a moderate and late rise in CSF protein level with no cells. Monoclonal IgM-kappa against MAG/SGPG/SGLPG, was detected; anti-MAG antibody titre in the serum was 20 059 BTU (N<1000). A small IgM-kappa paraprotein was identified by immunofixation. Electron microscopy failed to show nerve fibers with widening of outer lamellae of the myelin. There is no clinical improvement after different treatments, immunoglobulins IV, cortisteroids, plasma exchange, rituximab. CONCLUSION: It is not known whether this neuropathy is an atypical form of PNMAG or an CIDP associated with anti-MAG. When ENMG show a disproportionate slowing of conduction in distal segments of motor nerves, one should screen the serum with immunofixation to identify small monoclonal components. If IgM-MGUS is present, search should be undertaken for anti-MAG/SGPG/SGLPG antibodies. Diagnosis enables optimal treatment using, in severe cases, expensive current strategies with immunoglobulins IV, plasma exchange, and corticosteroids, or, in the event of no response, rituximab before resorting to more toxic drugs like cyclophosphamide.

[Screening for anti-glycolipid antibody profiles from patients with immune-mediated peripheral neuropathies by Dotzen Ganglio Profile Antibodies]. / Les anticorps anti-glycolipides dans le diagnostic des neuropathies périphériques auto-immunes par la technique Dotzen Ganglio Profile Antibodies.

The presence of anti-glycolipid specific antibodies have been found to be associated with acute and chronic immune-mediated peripheral neuropathies. Recently a number of anti-glycolipid antibody assays have became commercially available. In this study we established specific anti-glycolipid antibody profiles in a series of sera by the Dotzen Ganglio Profile antibodies. This kit screens for the simultaneous detection of ten anti-glycolipid antibodies against GM3, GM2, GM1, GD3, GD1a, GD1b, GT1a, GT1b, GQ1b gangliosides and sulfatides of the IgM and IgG classes. Sera from 89 patients with acute and chronic neuropathies were selected in a well-characterized cohort of banked sera with anti-glycolipid antibody profiles identified by in-house immunodot assay. Serum from 52 clinical variants of Guillain-Barré syndrome with IgG autoantibody profiles and 37 chronic acquired peripheral neuropathy with IgM autoantibody profiles were tested. The assay correctly identified with good agreement 50 of 52 IgG antibody profiles and 32 of 37 IgM antibody profiles. The assay compared well with in-house immunodot assay. It is easy to screen 10 crossreacting glycolipid antibodies to establish specific antibody profiles to define different subgroups of immune-mediated peripheral neuropathies for classification and immune management.

[Diagnostic value of autoantibodies to MAG by ELISA Bühlmann in 117 immune-mediated peripheral neuropathies associated with monoclonal IgM to SGPG/SGLPG]. / Les autoanticorps IgM anti-MAG par Elisa Bühlmann: apport diagnostique dans 117 neuropathies périphériques auto-immunes associées à une IgM monoclonale à activité anti-SGPG/SGLPG.

The neuropathies associated with monoclonal IgM gammopathy reacted with glycoconjugated targets on a very antigenic epitope on the sulfated glucuronic glycolipids corresponding to SGPG and SGLPG (sulfoglucuronyl paragloboside and sulfoglucuronyl lactosaminyl paragloboside), myelin-associated glycoprotein (MAG) and sulfatide. Sometimes monoclonal IgM binds to a broad spectrum of gangliosides. The detection of targets of autoantibodies has considerable importance in the diagnosis and management of patients. It is not known whether the results of antibody tests are equally sensitive and specific for identification of involved auto-antigens. In this study we evaluated the results obtained using IgM reactivity against MAG by enzyme-linked immunosorbent assay (ELISA Bühlmann) with IgM reactivity against SGPG/SGLPG obtained by overlay thin-layer chromatography. We selected 117 patients with anti-SGPG/SGLPG monoclonal gammopathy and peripheral neuropathy and a control group of 102 peripheral neuropathies with 24 having IgM high titres of monoclonal IgM anti-ganglioside antibodies. The anti-MAG sensitivity was 0.97, specificity was 0.86. There is a crossreactivity between 8 (57%) monoclonal IgM antibodies anti-MAG and anti-ganglioside GM1 and 2 (28%) anti-disialylated gangliosides. These results indicate that in clinical practice, anti-MAG ELISA is useful for eliminating anti-MAG neuropathy, as well as for positive diagnosis for titres upper than 10,000 BTU. It is also alpha good test to appreciate clinical improvement after Rituximab treatment.

[Immunofixation compared to isoelectric focusing in the detection of oligoclonal bands in cerebrospinal fluid of multiple sclerosis patients]. / Comparaison de l'immunofixation après électrophorèse sur gel d'agarose avec la focalisation isoélectrique dans la détection des bandes oligoclonales d'IgG du liquide céphalo-rachidien de patients atteints de sclérose en plaques.

INTRODUCTION: Intrathecal immunoglobulins (Ig) synthesis, reflected by oligoclonal bands (OCBs) in cerebrospinal fluid (CSF) is observed in up to 90 percent of patients with clinically definite Multiple Sclerosis (MS). The gold standard laboratory test to establish the presence of OCBs in CSF of MS patients is isoelectric focusing (IEF). However, a quicker and less expensive method has been developed: immunofixation (IF). METHODS: The aim of this study was to compare these two methods carried out 74 CSF/serum pairs of MS, 103 CSF/serum pairs of subject controls and to determine their sensitivity and specificity. RESULTS: The agreement between results from IEF and IF was excellent (Kappa = 0.84). IEF sensitivity (78 percent) was not significantly different from that of IF (74 percent) (p = 0.3). Similarly, the specificity of IEF (93 percent) was not significantly different from that of IF (95 percent) (p = 0.2). CONCLUSION: IF is a semi automated method which is easier to perform than IEF and which appears to be as efficient as IEF.

[CSF levels and diagnostic utility of cerebrospinal fluid beta2-microglobulin]. / Valeurs usuelles et utilité diagnostique de la beta2-microglobuline dans le liquide céphalorachidien.

CSF levels of beta2-microglobulin reflect immune activation and lymphoid cell turnover in CNS. There were proposed as a reliable marker of lymphoproliferative disorders in central nervous system in viral infections, inflammatory diseases, autoimmune diseases and malignancies. The aims of this study were to measure beta2-microglobulin on the automate Vidas of bioMérieux in 122 paired CSF and serum from control patients. We evaluated whether or not the elevated levels beta2-microglobulin in CSF can be a useful marker for diagnosis of lymphoproliferative disorders in 108 patients with neurological diseases. The concentrations of beta2-microglobulin in the CSF and sera from control patients were respectively 1.3 +/- 0.5 mg/L and 2 +/- 0.6 mg/L. The normal CSF to serum beta2-microglobulin ratio was 0.6 +/- 0.19. A CSF to serum beta2-microglobulin ratio greater than 1 was closely associated with intrathecal synthesis beta2-microglobulin in CNS lymphoproliferative disorders. Elevation of CSF beta2-microglobulin ratio is a sensitive marker of central nervous system disease activity by infiltrating lymphocytes in intracranial lymphomas (10/10) and paraneoplastic neurological syndromes (2/3).

Chronic myelopathies associated with human T-lymphotropic virus type I. A clinical, serologic, and immunovirologic study of ten patients in France.

Chronic myelopathy associated with human T-lymphotropic virus type I (HTLV-I) has been described in HTLV-I endemic areas. In Paris, 167 neurologic patients were screened for HTLV-I by enzyme-linked immunosorbent, indirect immunofluorescent, and Western blot assays. Ten of the 11 patients with positive results had a chronic spastic paraparesis with IgG oligoclonal bands and elevated HTLV-I antibody index. Two of them had been born and were living in France, without HTLV-I risk factors. Evoked potentials were abnormal in the nine tested patients and brain magnetic resonance images in three of seven patients. No improvement was observed with steroid treatment. A retrovirus similar to HTLV-I was isolated in five cases at different periods of the disease. Hypotheses of limited endemic areas in western countries are discussed. Early presence and persistence of HTLV-I suggest that it is the etiologic agent.

Human retroviruses HTLV-I, HIV-1, and HIV-2 and neurological diseases in some equatorial areas of Africa.

HTLV-I is associated with tropical spastic paraparesis (TSP) in the Caribbean area and with certain chronic myelopathies termed HAM (HTLV-I-associated myelopathy) in Japan. In order to investigate the situation in Africa, we tested for HTLV-I, but also for HIV-1 and HIV-2 antibodies, 94 patients with epidemic spastic paraparesis (ESP) from Zaire and Tanzania, 26 cases of sporadic spastic paraparesis (SSP) and 21 cases of tropical ataxic neuropathy (TAN), both from Ivory Coast, and 319 unselected neurological patients from Ivory Coast, Congo, and Tanzania. While none of the 94 ESP cases nor any of the 21 TAN patients exhibited antibodies to any retrovirus, 4 of the 26 sporadic spastic paraparesis patients had high HTLV-I antibodies in their sera and cerebrospinal fluid (CSF). Three of those were clinically and immunologically identical to TSP, as observed in persons from the Caribbean region, and the fourth case, a poorly explored chronic pyramidal syndrome, could also represent a TSP. Only one of these four cases originally had HIV-1 antibodies. Among the 319 unselected patients, only 5 (1.6%) had HTLV-I antibodies, but 32 (10%) had HIV-1 antibodies and 14 (4.4%) had HIV-2 antibodies, with a number of combined infections, indicating that retroviruses represent potentially important etiological agents for African neurological diseases.

Dot-blot immunodetection of antibodies against GM1 and other gangliosides on PVDF-P membranes.

A simple and rapid assay for detection of antibodies against GM1 and other gangliosides (GM3, GM2, GD1a, GD1b, GT1b, GD3) is described. Purified gangliosides were applied individually in 1 microliter of methanol to polyvinylidene difluoride (PVDF) membranes. Anti-ganglioside antibodies in human sera were allowed to bind and were revealed with a second antibody coupled to peroxidase. The specificity of antibodies binding to gangliosides was confirmed using established techniques to detect anti-ganglioside antibodies such as immunostaining of gangliosides after high performance thin layer chromatography according to Derrington et al. (1989) and ELISA procedure according to Adams et al. (1991) or using the ability of cholera toxin beta subunit to remove GM1 bound antibodies. The dot-blot assay is the simplest and quickest method to run and it appears to be suitable for large routine screening detection of anti-ganglioside antibodies in sera of patients with neurological diseases.

Value of cerebrospinal fluid cytochemical examination for the diagnosis of congenital toxoplasmosis at birth in France.

BACKGROUND: Because of routine screening and treatment of pregnant women for Toxoplasma infection in France, most neonates born to mothers who seroconverted during pregnancy are either not infected or asymptomatic. Early diagnosis relies mainly on radiologic, ophthalmologic and biologic tests. Cerebrospinal fluid (CSF) cytochemical evaluation is one of several tests performed in parallel to increase the overall sensitivity of the diagnostic evaluation. Our goal was to assess the value of cytochemical examination and to confirm whether using a portion of available CSF for this analysis is legitimate. METHODS: The individual performance of each of the two cytochemical tests and their combined value when used in parallel were assessed. These findings were then compared with the anti-Toxoplasma IgM and IgA serum titers and the clinical, ophthalmologic and radiologic findings at birth. RESULTS: CSF cytochemical analysis was possible in only 52% of the 233 children in the study. Our results in 112 children indicated poor sensitivity estimates. There was no significant change in the posttest probability of infection compared with the pretest estimation of risk in cases of a negative finding. After a mean follow-up of 80 months there was no evidence that CSF cytochemistry helped predict the risk of sequelae. CONCLUSION: In our setting cytochemical examination did not significantly contribute to the diagnosis of congenital infection at birth. Because of the limited quantity of CSF available, we suggest the use of other methods with higher yield.

Enzyme-linked immunoadsorbent assay for serum IgE: evaluation in four centres.

We report an evaluation of a commercially available kit, the Biomérieux IgE-kit, for determination of total IgE in serum by the EIA double antibody sandwich method. Results by this procedure and PRIST (Pharmacia) show a degree of association (r) of 0.98 and a regression equation of log Y = 0.79 log PRIST + log 3.31. Correlation between the IgE kit and RIST shows a degree of association of 1.00 and a regression equation of log Y = 1.01 log RIST--log 1.05. Between-laboratory standard deviations are 3%, 3%, and 15% for the IgE concentrations of, respectively, 83, 285, and 900 IU/ml. Similarly, intra- and inter-assay correlations were performed on 60 lyophilised serum samples tested in the four centres. No protein interference was found except for cryoprecipitates. The favourable correlation with existing procedures and the feasibility of this kit offer a new way of measuring IgE levels.

[Anti-GD1b IgG positive case of overlapping Ficher's and Guillain-Barré syndromes]. / Une forme frontière de syndrome de Guillain-Barré sensitif proche du syndrome de Miller Fisher avec IgG anti-GD1b.

We describe a patient who developed overlapping sensory ataxic form of Guillain-Barré syndrome (GBS) and Miller Fisher syndrome (MFS) following Campylobacter jejuni infection. Two cerebrospinal fluid examinations shown albuminocytologic dissociation associated with Campylobacter jejuni infection after tongue pierced. He had high titers of monospecific anti-GD1b IgG antibody. Because of the rarety of this disorder the diagnostic was difficult. There is a close association of IgG anti-ganglioside GD1b antibodies in sensory ataxic GBS. The findings of the present study show that antibody to GD1b ganglioside is one of the immunological factors in the pathogenesis of sensory ataxic form of GBS, a rare specific immuno-clinical variant form of GBS with prominent sensory ataxia.

[Role of isoelectric focusing of cerebrospinal fluid immunoglobulin G in the early biological assessment of multiple sclerosis]. / Apport de la focalisation isoélectrique des immunoglobulines G du liquide céphalorachidien dans le bilan biologique précoce de la sclérose en plaques.

A retrospective study was carried out at the Neurological and Neurosurgical Hospital of Lyon in order to evaluate the interest of detecting IgG oligoclonal bands by isoelectric focusing with IgG immunorevelation for the early diagnosis of multiple sclerosis (MS). Patients have been grouped according to their disorders: multiple sclerosis (281 cases), definite (182 cases) and possible (99 cases), others inflammatory neurological diseases (63 cases), various non-inflammatory neurological disorders (180 cases) and indefined neurological disorders (664 cases). The following examinations were performed: CSF cell count and cytology after concentration and cytocentrifugation, CSF and serum determination of albumin and IgG with CSF/serum ratios, agarose gel electrophoresis and isoelectric focusing of oligoclonal IgG. The technique used was isoelectric focusing using agarose gel, transfer onto PVDF membrane and then IgG immunorevelation with biotinylated anti-human IgG antibodies. Isoelectric focusing with IgG immunorevelation is the most sensitive (94%) and specific (96%) technique. Isoelectric focusing with immune detection can be recommended as the most efficient test (gold standard) for the detection of chronic CNS inflammation.

[Valve of the use of benzethonium chloride for turbidimetric analysis of cerebrospinal fluid proteins with an automatic analyzer]. / Intérêt de l'utilisation du chlorure de benzéthonium pour le dosage turbidimétrique des protéines du liquide céphalorachidien en analyse automatique.

We have adapted Iwata and Nishikaze's benzethonium chloride turbidimetric method for the assay of CSF proteins to the techniques of continuous flow and the centrifuge analyser. The proposed technique presents several advantages: benzethonium chloride forms a stable precipitate with the proteins with a slow kinetic of formation, enabling adaptation to the centrifuge analyser; the response obtained is identical for albumin and immunoglobulin G; this very sensitive technique allows the use of micro-samples. Studies of repeatability and the correlations made with other techniques give very satisfactory results.

[Diagnosis and biological monitoring of 6 neurosyphilis cases: value of cerebrospinal fluid analysis]. / Diagnostic et surveillance biologique de six neurosyphilis: apport de l'étude du liquide céphalorachidien.

Our objective is to assess the relevance of the different laboratory findings in cerebrospinal fluid (CSF) and serum for the diagnosis and survey of active neurosyphilis. A retrospective study of six hospitalized neurosyphilitic patients at Neurological Hospital of Lyon from 1987 to 2002 was carried out. Six males were found, aged from 29 to 72 years. Neurosyphilis can be group in two categories: early (meningeal and meningovascular neurosyphilis) and late (progressive general paralysis and tabes dorsalis). All were tertiary stage and HIV negative. We performed in CSF, white and red cell count, cytology, total protein, glucose levels, in CSF and serum, albumin, total IgG, IgA, IgM for calculation of albumin quotient and IgG, IgA and IgM index. Serological tests for syphilis in CSF and serum are VDRL and TPHA. To increase the reliability of treponema antibody tests, the ratio of serum-to-CSF content of albumin is used to assess intrathecal production of treponema antibodies, especially the treponema pallidum hemagglutination assay (TPHA index). The CSF changes in neurosyphilis included elevated cell count with lymphocytic-plasmocytic cell reaction, increased protein content, strongly positive IgG index, numerous positive IgG oligoclonal bands, positive blood and CSF serology. Serological tests are difficult to interpret. Examination of CSF played a major role in the diagnosis and treatment of all forms of neurosyphilis. The CSF abnormalities improved with clinical improvement, especially in meningeal and vascular neurosyphilis, but the response in paresis and tabes was slower or nonexistent. Pleocytosis and protein are indicators of inflammatory activity in the central nervous system and are used as a clinical guide in the diagnostic, for treatment and re-treatment.

[Detection of antibodies binding to myelin in 75 neuropathies associated with IgM gammopathy]. / Détection des anticorps anti-myéline: mise au point et évaluation dans 75 cas de neuropathies associées à une IgM monoclonale.

Polyneuropathies associated with IgM monoclonal gammopathy (IgM-MG) are the most frequent types of peripheral neuropathies associated with monoclonal gammopathy. The pathogenic relevance of IgM-MG in peripheral neuropathies is supported by several arguments. The more significant are pathological data on nerve biopsies and the demonstration of IgM antibody activity to peripheral nerve antigens, mainly myelin-associated glycoprotein (MAG) and, sulfated 3-glucuronyl paragloboside (SGPG) and sulfated 3-glucuronyl lactosaminyl paragloboside (SGLPG). The objective of this study was to determine the performance characteristics of 3 immunoassays for detection of anti-myelin antibodies in neuropathy associated with monoclonal IgM gammopathy. Monoclonal IgM may show antibody activity to carbohydrate epitopes shared by several nerve specific antigens. Results obtained with three reliable assay systems, indirect immunofluorescence for antibodies to myelin sheaths (33%), thin layer chromatography for anti-SGPG/SGLPG antibodies (54%) and Western-blot for anti-MAG antibodies (39%). Comparing the different assay systems for carbohydrate structure present on both MAG and SGPG/SGLPG on myelin sheath, the thin layer chromatography appeared to be more sensitive and reliable than Western blot.

[Monoclonal IgM autoantibody activity vis-à-vis glycoconjugates of peripheral nerves: apropos of 112 cases]. / Activité autoanticorps des IgM monoclonales vis-à-vis des glycoconjugués du nerf périphérique: à propos de 112 cas.

Serum IgM and IgG autoantibodies against carbohydrate epitopes on glycolipids and glycoproteins have been determined in a series of 112 neuropathies associated with monoclonal IgM (M-IgM) by different immunological techniques. The M-IgM anti-myelin sheath antibodies were determined by indirect immunofluorescence microscopy, the M-IgM anti-myelin associated glycoprotein (MAG) antibodies by western-blot analysis, the M-IgM anti-SGPG and SGLPG antibodies by immunodetection on thin-layer chromatography, the M-IgM anti-ganglioside GM3, GM2, GD3, GM1, GD1a, GD1b, GT1b, GQ1b and anti-sulfatide antibodies by immunodot-blot assay on membrane. Among the 112 M-IgM, 81 had autoantibody activity against nerve glycolipid antigens concentrated in peripheral nerve (72%). M-IgM bound strongly to myelin sheath in 34,5% of cases, to MAG in 38% of cases, to SGPG/SGLPG in 52% of cases, to gangliosides in 21.5% of cases and to sulfatide in 26 % of cases. Six M-IgM autoantibody activity profiles have been described in correlation with distinct clinical syndromes: - the M-IgM autoantibody activity profile against the carbohydrate epitope common to the glycolipids SGPG and SGLPG and myelin associated glycoprotein (MAG) in chronic demyelinating sensitive and sensorimotor peripheral neuropathies (58 patients, 52%); - the M-IgM autoantibody activity profile against immunodominant GM1 in demyelinating pure motor neuropathies (9 patients, 8%); - the M-IgM autoantibody activity profile against immunodominant disialosylgangliosides in chronic demyelinating sensitive ataxic neuropathies (8 patients, 7%); - the M-IgM autoantibody activity profile against immunodominant GM2 in demyelinating motor polyneuropathies (3 patients, 2.5%); - the M-IgM autoantibody activity profile against immunodominant GD1a in pure motor polyneuropathies (2 patients, 2%); - the M-IgM autoantibody activity profile against immunodominant GT1b and polysialosylgangliosides in one acute polyradiculoneuropathy (1%). The M-IgM recognized all gangliosides except GM1 and GM2. The neuropathies associated with IgM monoclonal gammopathy with autoreactive specificity form distinct syndromes. In 27.5% of cases, M-IgM had no identifiable activity autoantibodies.