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Les caseines α, β et κ ont ete dosees par immunonephelemetrie microparticulaire, dans 1300 echantillons de lait, collectes bimensuellement pendant 13 mois (octobre 1992 a octobre 1993), aupres de 50 troupeaux de Normandie. Les concentrations de ces 3 caseines sont comparees a celles d'autres parametres de composition, mesures sur les memes laits (matieres proteiques, matieres grasses, lactose et extrait sec total). Les principaux facteurs, lies a l'exploitation, au troupeau, a sa conduite et a son alimentation, qui determinent les parametres de composition du lait a la production sont ensuite analyses. Ces memes parametres de composition biochimique et des parametres de coagulation a la presure (temps de floculation, indice de raffermissement K15, indice de fermete A30) sont mesures, sur la meme periode, dans des laits crus et standardises en matiere grasse, utilises dans une fabrication fromagere industrielle. Realise dans un cadre de temps et d'espace limite, l'ensemble du travail envisage l'etude du lait depuis sa production jusqu'a sa valorisation par transformation fromagere. Il permet de retrouver des notions bien connues et abondamment publiees, tant au niveau biochimique (liens entre les parametres de composition, variation et variabilite de ceux-ci), que zootechnique (influence de la race, des potentialites pedologiques du sol, de la repartition des velages, de l'alimentation, des conditions de transition entre stabulation et pâturage) et technologique (influence relative des parametres de composition sur la coagulabilite a la presure et les rendements de fabrication fromagere). L'immunonephelemetrie microparticulaire, qui permet un dosage specifique et precis des differentes caseines du lait, apparait comme une technique originale d'immunoanalyse, completant les moyens traditionnels d'evaluation de la qualite du lait.

Crude thyroid peroxidase extracted from human thyroid microsomes was covalently bound onto polyacrylic and polyfunctional copolymerized microparticles. We observed agglutination of the thyroid peroxidase-microparticle conjugate with 13 monoclonal antibodies (mAbs) specific for epitopes on four different antigenic domains of human thyroid peroxidase (TPO; EC 1.11.1.7), after addition of anti-mouse immunoglobulins. We quantified agglutination by measuring with a specially designed nephelometer the light scattered by the conjugates. This allowed us to develop a microparticle-enhanced nephelometric immunoassay for human anti-TPO autoantibodies (aAbs) with defined epitopic specificity, based on the ability of aAbs to inhibit mAb-induced agglutination. Applied to patients with autoimmune thyroid diseases, this assay confirmed the polyclonality of anti-TPO aAbs and their preferential reactivity toward epitopes located on the A and B antigenic domains of the TPO molecule. The same specificities seem to be present in patients with Hashimoto thyroiditis or Graves disease.

A microparticle-enhanced nephelometric immunoassay was recently described, where polyacrylic, hydrophilic, and polyfunctional microparticles are used as the solid phase. It is a one-step immunoassay based on the nephelometric quantification of microparticle agglutination. In such assays, the measurement of analytes at low concentration may be impaired by the need of using undiluted biological samples. This leads to work with high concentrations of several proteins liable to interfere with the agglutination process. In this paper, we report on a study performed with human serum and purified proteins, which were assayed by classical analytical methods. This work identified three major components of human serum specifically involved in yielding polyacrylic microparticle instability: complement fraction C1q, fibronectin, and immunoglobulins G. In this order of importance, they all showed a marked ability to be adsorbed on the microparticle's surface. Pretreatment of human serum with microparticles decreased the concentrations in C1q (82%), fibronectin (16%), and immunoglobulin G (4%) very unequally. However, it allowed the elimination of microparticle instability, consequently providing the possible use of such polyacrylic microparticles in a one-step nephelometric immunoassay of analytes at low concentration in biological samples, without washes or phase separation.

To hydrophilic, polyfunctional spherical microparticles of predetermined diameter, produced by copolymerization of acrylic monomers, we covalently bound human thyroglobulin. The thyroglobulin-microsphere conjugate was agglutinated, in the presence of antimouse immunoglobulins antiserum, by four monoclonal antibodies, each recognizing a different antigenic domain on the thyroglobulin molecule. These agglutinations were quantified by measuring with a specially designed nephelometer the light scattered by clusters of the conjugates. Agglutination with the monoclonal antibody recognizing antigenic domain II of the thyroglobulin molecule was specifically inhibited by some human sera that contained antithyroglobulin autoantibodies. This allowed us to develop a microparticle-enhanced nephelometric immunoassay for these autoantibodies with defined epitopic specificity. Using this assay, we detected and quantified antithyroglobulin autoantibodies in serum samples from all eight patients examined with Hashimoto disease and from most (75%) patients with untreated Graves disease.

Rabbit anti‐native bovine s‐casein antiserum reacted with native s‐casein and fragments f( 1–105/7) and f( 106–209) formed during s‐casein proteolysis by plasmin. Agglutination of s‐casein‐coated microparticles by anti‐native s‐casein antiserum was weakly inhibited by s‐casein f(1–105/7) and s‐casein f( 106–209) (0·04 and 1·4%, respectively, compared with native s‐casein). Immunoreactivity of these s‐casein peptides in microparticle‐enhanced nephelometric immunoassay was more preserved in the whole s‐casein than in its isolated fragments. The protein concentration producing 50% inhibition of the s‐casein‐coated microparticle agglutination with anti‐native s‐casein antiserum increased during s‐casein denaturation. A microparticle‐enhanced nephelometric immunoassay, quantifying changes of this inhibiting protein concentration, permitted detection of alteration of the immunoreactivity of s‐casein during its plasmin proteolysis and heat denaturation, providing an adequate test for the integrity of the whole m...

This article describes a microparticle enhanced nephelometric immunoassay (Nephelia) applied to the quantification of the thymic peptide hormone thymulin. Nephelia uses antibody recognition by the antithymulin antiserum in a competitive reaction between free thymulin and thymulin bound to the microspheres. The binding between microsphere and thymulin is achieved with the aid of a protein carrier. The sensitivity of the competitive reaction varied with the protein carrier and the antiserum sample. The most efficient reaction was obtained with the thymulin-metallothionein-microsphere conjugates; as little as 5 pg/ml of thymulin could be detected. In adult human serum or in its ultra-filtrate, spiked synthetic thymulin was totally recovered. Measurement of thymulin in serum or ultra-filtrate samples demonstrated the presence of interference from molecules in the serum. Nephelia led to the same conclusions as those reported with other methods and performs as well, and is more simple to use than radio- or enzymo-immunoassays for thymulin measurement.

A microparticle-enhanced nephelometric immunoassay (NEPHELIA ® ) was developed for the determination of α-lactalbumin and β-lactoglobulin in bovine milk, whey, and curd from soft cheese (Camembert-type cheese) and pressed cheese (Saint Paulin-type cheese). Diluted milk, whey, and dissolved curd samples were used without pretreatment and mixed with α-lactalbumin-coated or β-lactoglobulin-coated microspheres and highly diluted anti-α-lactalbumin-specific or anti-β-lactoglobulin-specific antiserum. After a reaction time of 1h, the light scattered by the clusters of coated microspheres was measured using a nephelometer and compared with calibration curves developed with a low heat milk powder, corrected for its heat-sensitive β-lactoglobulin content. Recovery (97.2 to 102.2%) and precision (coefficients of variation from 1.4 to 6.1% for milk and whey) studies showed the reliability of this method for the quantitation of whey proteins.

α s -Casein and κ-casein were measured in milk and curd by a microparticle-enhanced nephelometric immunoassay (NEPHELIA ® ). Specifically designed microspheres were coated with antigen (α s -casein and κ-casein) and then were agglutinated by specific antibodies. The light scattered by the agglutinates was quantified with a nephelometer. Antigen-coated microsphere agglutination was inhibited by free antigen solution, allowing its measurement. Calibration curves for α s -Casein and κ-casein in milk and curd, performed with a low heat milk powder as standard, largely covered the usual concentrations of caseins. Accuracy (average ratios of recovery were 98.7 and 104.3%) and precision (coefficients of variation from 1.9 to 7.4%) assessed the fidelity of the method. NEPHELIA®, applied to casein determination, offers many advantages over the classical methods of milk protein measurement: high dilution of the reagents, no pretreatment of the samples, enhanced sensitivity (few micrograms per liter), short reaction time (1h), and easy use (no washing or phase separation).

A microparticle-enhanced nephelometric immunoassay (NEPHELIA ® ) has been developed for the measurement of milk, whey, and curd proteins (α s -casein, κ-casein, α-lactalbumin, and β-lactoglobulin). This new method was applied to measure milk protein variations in a year-long study. The protein levels and their chronological evolution agree with other published data. The effects of some technological treatments on these measurements were studied: α-lactalbumin and κ-casein were not modified during freezing-thawing cycles; β-lactoglobulin and α s -casein measurements were strongly influenced by freezing; the determination of heat-processed β-lactoglobulin in the presence of κ-casein was also altered; the technological treatments applied to raw milk for pasteurization and fat standardization of milk had no influence on the proteins' measured values. The β-lactoglobulin: α-lactalbumin ratio was determined as a good indication of heat denaturation. It was unmodified in standardized milk as well as in whey. The κ-casein level in milk was correlated with some cheese-making parameters, particularly with soft and pressed cheese yield, which could be a good predictive factor in cheese making.

Polyfunctional hydrophilic microspheres (MS) can be produced by copolymerisation with gamma-irradiation of acrylic monomers. Transferrin (TRF) can be covalently bound to these MS by reaction between aldehyde groups of the MS and primary amino groups of the protein. MS-TRF conjugates thus obtained are agglutinated by specific antiserum and this agglutination is inhibited by free TRF. Agglutination and inhibition are quantified by measurement of the light scattered by MS-TRF conjugate clusters with a specially designed nephelometer, a process designated as microparticle enhanced nephelometric immunoassay (NEPHELIA (R)) for TRF. Recovery, correlation and reproducibility studies, simultaneously performed in three different laboratories, show that this TRF immunoassay is accurate for a large concentration range. NEPHELIA (R) may appear as an alternative method for a large variety of molecules.

Beta‐casein determination has been performed in cow's milk by a microparticleenhanced nephelometric immunoassay. Hydrophilic monodisperse beta‐casein coated microspheres, specifically conceived as an antigen‐antibody reaction support, are agglutinated by anti‐beta‐casein antiserum. Free beta‐casein inhibits this immunoagglutination, allowing its fast (30 min) and sensitive (1 μg l‐1) quantification with accuracy and precision, by nephelometric measurement of the light scattered by the beta‐casein coated microsphere agglutinates. This immunoassay of beta‐casein is easy to perform in milk (no washing, no phase separation, nor sample pretreatment). Microparticle‐enhanced nephelometric immunoassay appears as an alternative method to measure a large variety of molecules in dairy analysis.

Covalent binding of gamma chains of IgG, whole IgA, and mu chains of IgM on polyfunctional hydrophilic microspheres (MS) yields MS-Ig conjugates, usable as reagents in new microparticle-enhanced nephelometric immunoassays (Nephelia). The principle of the assays is inhibition by free analyte (IgG, IgA, and IgM) of agglutination of the MS-Ig conjugate with specific antiserum, the light scattered by the aggregates being measured with a nephelometer. The immunoglobulin assays developed are easy to perform (single-step assays, no washing or phase separation) and sensitive (high dilution of biological samples to exclude interferences and pretreatment). Analytical recovery results (95.4-101.2%) and correlations with generally used commercial assays (r = 0.86-0.98) indicate that the assays are accurate for large concentration ranges of immunoglobulins. Precision sxtudy gives CVs = 2.8-9.6%. Nephelia appears to be useful for quantifying a large variety of biological molecules.

To optimize antigen-antibody reactions, we have synthesized chemically well-defined hydrophilic microspheres. Proteins or haptens were covalently linked to these carriers. When the microsphere conjugates were agglutinated by the corresponding antiserum, the size of the complex artificially increased during the immunological reaction. After optimizing various parameters such as the hydrophilic character, repulsion charges, and amount of antigen coupled to the microspheres, we developed a rapid and sensitive immunoassay based on laser light scattering by the complexes.

A microparticle-enhanced nephelometric immunoassay was developed for myoglobin quantitation in human serum. It uses rabbit antimyoglobin serum and hydrophilic polyacrylic microparticles covalently coated with baboon myoglobin in a competitive immunoagglutination system. The level of microparticle agglutination is assessed with a specially designed nephelometer. This sensitive (45 ng/ml of myoglobin detected in serum) and accurate (coefficients of variation from 3.0% to 8.2% in precision study and linear recovery of myoglobin in overloaded sera) immunoassay was evaluated with human sera from patients suffering from acute myocardial infarction. Myoglobin levels in patient's serum on admission appeared to be correlated with clinical and biological parameters assessed in emergency wards and later. This new, rapid, and easy microparticle-enhanced nephelometric immunoassay could thus be useful in emergency conditions for the early quantitation of serum myoglobin.

Eleven proteins (immunoglobulins IgG, IgA, IgM, orosomucoid, alpha 1-antiproteinase, haptoglobin, ceruloplasmin, C-reactive protein, transferrin, prealbumin and alpha 2-macroglobulin) in human serum were quantitated by a new microparticle-enhanced nephelometric immunoassay. This is a one step competitive assay, based on the nephelometric measurement of light scattered by clusters of protein-coated microparticles specially synthesized for that use. Statistical evaluation (precision, recovery and method comparison) shows that the determination of serum proteins is reliable and accurate for wide ranges of concentration and that the method is quite adequate for strongly increased concentrations. This microparticle-enhanced nephelometric immunoassay appears to offer an alternative method for routine measurement of a great variety of serum proteins at high and intermediate concentrations, which are usually quantified by radial immunodiffusion or conventional immunonephelometry. On account of its sensitivity, it can also be used for the determination of relatively low concentrations of analytes.

Polyfunctional hydrophilic microspheres of 125-nm diameter can be produced by copolymerization of acrylic monomers. Purified c-reactive protein (CRP) was covalently bound to these new micropheres, and the conjugate obtained was used as reagent in a microparticle-enhanced nephelometric immunoassay for human CRP. This assay was based on the measure, with a specially designed nephelometer, of the light scattered by aggregates formed during the immunoagglutination of the conjugate with anti-CRP antiserum. Sensitive inhibition of this agglutination by free CRP (6 ng/ml) allowed CRP quantitation in highly diluted serum samples (1/500-1/2,000), excluding any interference or sample pretreatment. The CRP assay was easy to perform (no washing or phase separation), reliable (coefficients of variation ranged from 1.3% to 9.3% for within-run and between-run determinations), and accurate (mean percentage of recovery: 104%; correlation coefficients with accepted analytical methods greater than or equal to 0.97) over a large range of concentrations. The inhibition mode excluded errors in the antigen excess zone and provided total security at high concentrations.

Summary - A microparticle-enhanced nephelometric immunoassay of bovine immunoglobulins G is reported. lt is based on the nephelometric quantification of the competitive immunoagglutination of covalently coated microparticles. This new immunoassay is easy to perform (1-step, no sample pretreatment, no washing or phase separation), fast (1 h at most), sensitive (8 Ilgl1 of immunoglobulins G significantly detected in the reaction mixture), accu rate (linear recovery of immunoglobulins G in overloaded milks) and reproducible (CVs from 2.3-10% in within- and between-run precision studies). The potential of this microparticle-based immunoassay ls discussed with regard to the other quantitative immunoassays (radial immunodiffusion and convention al immunonephelometry in parneular) used in the determination of milk immunoglobulins G.

Human derived fibrin glues are being used with increasing frequency in periodontal surgery. Three different fibrin glues were tested in an in vitro system for gingival fibroblast proliferation. The results show a cytocompatibility of these products which justifies their employment in periodontal therapy.

Perturbations in T cells and T cell subsets of peripheral blood lymphocytes were looked for, using monoclonal antibodies, in nine patients with rheumatoid arthritis (RA) and four patients with systemic lupus erythematosus (SLE). All SLE patients were in an acute phase of their disease, but had not yet received steroids. Seven of the nine RA patients presented an active illness, recently diagnosed in five cases, and received no steroids nor D-penicillamin. T cell subsets alterations responsible for abnormal values of the OKT4 + /OKT8 + immunoregulatory ratio, were improved by in vitro incubation of the lymphocytes with synthetic thymulin in eight out of nine RA patients. No significant modification occured for SLE patients' lymphocytes. These results support the possible beneficial role of thymulin in the treatment of rheumatoid arthritis.

Immunohistomorphometric analysis of the tonsils from a series of patients with anaphylactoid purpura or Berger's disease showed abnormal proportions of gamma- and alpha-isotype-producing cells. Conversely, renal immunofluorescence (IF) performed on kidney biopsies from 2 patients with hematuria and clinical symptoms suggestive of one or the other of these conditions failed to confirm the suspected diagnosis. Immunohistomorphometric analysis of these patient's tonsils showed normal proportions of gamma- and alpha-isotype-producing cells. These negative results suggest that strong relationships exist between mucosal abnormalities and renal deposition of IgA in hematuria.

Protein-energy malnutrition (PEM) leads to an immune deficiency, which is now well documented. Some investigators have suggested that the associated zinc deficiency is important in thymic involution and changes in cellular immunity. To evaluate the respective roles of nutritional deficiency, infection, and zinc in the alteration of thymic function, we measured the amounts of thymulin (facteur thymique sérique, or FTS) and of Zn in the thymus glands of 58 Senegalese children who died in various stages of malnutrition. In the severe forms (marasmus, kwashiorkor, and marasmic kwashiorkor) the thymus was tiny and contained very little thymulin. The Zn content of the thymus was high whatever the nutritional state of the subject and was related significantly only to the presence of infections. In Senegalese children thymic atrophy and depleted thymulin content are associated with severe PEM but not systemic infection or depleted thymic Zn content. (Résumé d'auteur)

Scanning electron microscopy allows a tridimensional morphological study of the cellular elements of the pathological human synovial fluid. The cells are grouped into two populations: macrophage cells and round cells, whose differentiation is more difficult: polynuclears, lymphocytes and synovial cells. The combination of scanning electron microscopy and X-ray diffraction makes it possible to describe and indentify crystals of sodium urate and of triclinical, dehydrated calcium pyrophosphate.

The authors studied one case of pigmented, villonodular synovitis (PVNS) of the hip by means of optical microscopy and by transmission and scanning electron microscopy. Scanning electron microscopy showed that the surface of the PVNS is completely different from that of rheumatic synovitis, in particular that of rheumatoid synovitis. The composition and the cellular morphology of the outer layer of the PVNS appear, however, to be similar to those of normal synovial membrane of arthrosic synovial membrane. Clumps of red corpuscles, enclosed in a fibrin network, were visible on the surface of the PVNS in a way that the authors has never seen previously in the 19 other human synovial membranes, normal and pathological, they had studied in this way. The totality of the microscopic findings confirms the importance of the role played by the intra-articular and intra-synovial haemorrhages, and by the macrophage reactions that follow, in the development of the lesions that characterize PVNS.

Scanning electron microscopy permits three-dimensional morphological study of the outer layer of the synovial membrane. This article concerns the study of 15 surgical samples of normal and pathological human synovial membranes: 3 normal synovial membranes, 6 inflammatory synovial membranes, 5 arthrosic synovial membranes, 1 tuberculous tenosynovitis. The samples were washed, fixed in a mixture of glutaraldehyde and iso-osmotic paraformaldehyde, dehydrated in increasing concentrations of alcohol and at the critical point, and then subjected to double metallization (aluminium and gold). Certain portions were treated with hyaluronidase. Hypertrophy of the villi, considerable in inflammatory synovial membranes, minimal in arthrosic synovial membranes, and absent in the normal synovial membrane, was confirmed. The outer layer is composed of cells of different sizes with spaces betwen, in which images indicating intercellular bridges can just be seen. The surface of the cells is irregular and covered with numerous microvilli. The arthrosic synovial membrane is poorly with large cells; in contrast in an inflammatory synovial membrane they are numerous, globular, and project from the surface.

This work, performed by immunofluorescence on the mouse embryo, makes use of the remarkable specificity of human pathological anti-striated and anti-smooth muscle auto-antibodies. It makes it possible, on the one hand, to date the appearance of smooth muscle Actomyosin during embryogenesis, and, on the other hand, to witness the appearance of immunological distinctions between contractile proteins of smooth and striated muscle.

Immunologic characteristics of cells present in rheumatoid synovium from 15 patients were analyzed either "in situ" on frozen sections or after elution. Monoclonal antibodies directed against T cell subpopulation antigens and anti-Ia-like were used. T cells bearing the phenotype T3+, T4+, Ia+ are numerous, and they appeared gathered in lymphoid follicles and in perivascular areas. They are in close relationship with large Ia+ cells probably macrophagic in nature. Numerous dendritic cells as well as intimal cells are also Ia+. Some ratios T8+/T4+ cells are higher than results previously reported. This discrepancy could be related to drugs received by the patients before surgery.

Recent publications have reported a frequent association between IgA nephropathy and episcleritis. In this article, the authors report on the immunohistologic study of an episcleral biopsy obtained in a female patient with Berger's disease and frequent episodes of episcleritis. Numerous dimeric-IgA-secreting cells were demonstrated in the episcleral inflammatory infiltrate. It also should be mentioned that microhematuria often occurred within a few days after the beginning of episcleritis in this patient. These results suggest the participation of ocular mucosal immunity in some cases of IgA nephropathy.

After a brief review of clinical, biological and immunological features of post anesthesia hepatitis and hepatic auto-immunity, the authors attempt to determine whether certain forms of post-anesthesia hepatitis can be placed under the heading of autoimmune liver disorders, the mechanisms by which auto-immunity can be induced and modulated and the practical implications of these concepts, namely with regard to detection of subjects at risk.

Lymphocytes from five children suffering from ataxia telangectasia or various unclassified immune deficiencies were tested in vitro for their sensitivity to synthetic serum thymic factor (FTS). The percentages of cells bearing T cell markers were elevated after incubation with FTS at graded concentrations (0.25, 2.5 and 25 ng/ml), by microlymphocytotoxicity or indirect immunofluorescence, using monoclonal anti-Lyt1 antibodies. In four cases, more than 30% of the non-T non-B cells acquired the Lyt1 T cell marker. These four children had low levels of circulating FTS. In the fifth child, who had a normal serum FTS level, and in two age-matched controls, there was no significant increase in the percentage of cells bearing the T marker.

The pathogenesis of mesangial immunoglobulin A nephropathies was elucidated through the analysis of their clinical features and investigation of their biological characteristics. An alteration of the mucosal immune system is currently considered chiefly responsible for these diseases. A dysregulation of other compartments of the immune system is likely to enhance this abnormality and/or contribute to the persistence of immune complexes. Little is known, however, about the etiology of these renal diseases, and their treatment remains palliative or preventive.

Study of the synovial membrane and cartilage demonstrating two destructive arthropathies of the knee diagnosed in subjects with articular pseudogout. Scanning electron microscopy reveals the presence of many crystals on the surface of the cartilage and the synovium and in the depth of the cartilage. These can be grouped into two families on the basis of dimensions and morphology. The first consists of those shaped like arrowheads and are large (80-100 microns long.) They were formally identified using Weissenberg's technique; dihydrated calcium hydrogenophosphate (CaHPO4.2H2O) is involved here. In the second family the crystallogenesis is different (prism or lozange-shaped) and the crystals themselves have not been identified with certainty because of their tiny size (20 microns). The hypothesis is proposed that the crystals of dihydrated calcium hydrogenophosphate properly belong to the destructive arthropathies of pseudogout; while not necessarily its cause, they may help explain its development.

Primary IgA nephropathy (Berger's disease) is characterized by renal deposits of IgA, the origin of which is still unknown. However, several clinical and biological findings suggest that these immunoglobulins might have a mucosal origin, and that such patients should present mucosal abnormalities. This paper reports the results of the immunohistomorphometrical analysis of tonsillar plasma cells from seven patients suffering from Berger's disease and seven controls also with recurrent tonsillitis. IgG, IgA, and IgM-secreting cells were enumerated after immunofluorescent staining of serial frozen-cut sections from 20 tonsils. In controls, a predominance of the IgG-secreting population, similar to this reported in the literature was observed (65% of IgG secreting cells and 29% of IgA plasma cells), while an inversion in the patients' plasma cells percentages was evidenced (IgG:37%, IgA:56%). This increment in the IgA population was paralleled by an augmentation of the number of dimeric IgA-secreting cells (75% of IgA plasma cells), stained both for cytoplasmic IgA and J chain. In controls, the latter cells were in similar proportions as previously reported by others (45% of IgA plasma cells). These results demonstrate an imbalance in the IgA-producing system of patients with Berger's disease, which is in keeping with the hypothesis favoring a mucosal origin for the mesangial IgA present in their kidneys.

An in situ analysis of immunological features in thyroids from 15 Graves' disease patients has been performed. This study included a search for immune complexes visualized near the follicle's basement membranes with fluorescent rabbit antisera to human IgG, IgA, IgM, C1q, C3 and C9. Cellular immunity was investigated on the humoral side by visualization of B cells and plasma cells. Two series of monoclonal antibodies (OKT3, 4 and 8, Leu 1, 2a and 3a) were used to label the infiltrating cells' membrane. These studies demonstrated the prevalence of T cells, a majority of them with OKT8/Leu 2a suppressor/cytotoxic phenotype. No correlation was found between this observation and peripheral blood T cell subsets analysis.

A comparative study under the scanning electron microscope of rheumatoid synovial membranes, 5 arthrosic synovial membranes, one tuberculous membrane, and 3 normal synovial membranes showed the pathological changes in the synovial membrane due to rheumatoid arthritis: Inflammatory aspect of the synovial fringes, surrounded by turgid and proliferative villous processes. Granular appearance of the endo-articular surface like a "pebble beach". Dome-shaped synoviocyte layer, standing out well above the subjacent intimal layer, associated with small round cells, also with a raised margin, covering most of the endo-articular surface. Plasma membrane of the superficial synovial cells, covered with numerous and various differentiations and abundant microvillous processes. Reticular deposits or layers, covering the apical poles of the synoviocytes.

Scanning electron microscopy has been used in conjunction with wavelength dispersive X-Ray spectroscopy and in correlation with X-Ray diffraction to define the populations of crystals present in rheumatic diseases. Microcrystals of monosodium urate, triclinic and monoclinic calcium pyrophosphate dihydrate, apatite, calcium hydrogen phosphate dihydrate and corticosteroids, among others, have been found in synovial fluid, in the intraarticular tissues (fibrocartilage, cartilage, and synovial membrane), and in the periarticular tissues (tendons and ectopic calcifications). Scanning electron microscopy in conjunction with wavelength dispersive X-Ray spectroscopy has made it possible to detect microcrystals, even isolated, to describe their morphologies, and to study their relations with the cells of the synovial fluid and with the collagenous and cellular structures of the synovial membrane and of the cartilage. It cannot replace X-Ray diffraction for the conclusive identification of microcrystals, but it can certainly help to improve the analysis of the various populations of crystals present in articular and periarticular rheumatic diseases.

A selected IgA deficiency was found in a 66 years old, DPH-treated epileptic female, suffering from polyarthritis. Familial survey brings information for genetic transmission of IgA decreased concentrations in her offspring, unrelated with HLA A, B, C system.

IgA nephropathy, as Berger defined it, is characterized by mesangial deposits of IgA, which are easily visualized by immunofluorescence on kidney biopsies. The structure (mono- or dimeric) of these IgA has not been clearly defined so far. Fifteen renal biopsies were studied to find out whether these IgA are serum monomers, or are polymers from a different origin. This was done by tissue fixation in vitro of free secretory component, which was then visualized by immunofluorescence (IF). In all 15 cases, the IgA deposits were shown to lack bound secretory component, but were able to bind, specifically, with the free secretory component. The presence of J chain in these deposits was also evidenced by indirect IF. These findings favour the hypothesis that these immunoglobulins are polymeric.