[Historic Development of Clinical Biology Laboratories in Luxembourg]. / Evolution historique des laboratoires de biologie médicale au Luxembourg.

After a short overview on the development of diagnostic tools in clinical biology at an international level from Antiquity towards today, a history of the clinical biology including public and private institutions in Luxembourg will be outlined.

Receptors for insulinlike growth factor I are defective in fibroblasts cultured from a patient with leprechaunism.

We previously have demonstrated that fibroblasts from a patient with leprechaunism exhibited markedly decreased insulin binding to insulin receptors and that the ability of insulin to stimulate glucose incorporation in the patient's cells was greatly impaired. In addition, the insulinlike growth factor, multiplication-stimulating activity (MSA), also exhibited an impaired ability to stimulate glucose incorporation in the patient's fibroblasts, although in normal fibroblasts this response appears to be mediated by an insulinlike growth factor receptor. The present study examines 125I-labeled insulinlike growth factor I (IGF-I) binding to patient's and control fibroblasts. 125I-labeled IGF-I binds to a specific IGF-I receptor in normal fibroblasts. At steady state, binding was inhibited by unlabeled IGF-I, IGF-II, MSA III-2, MSA II, insulin, and proinsulin, in order of potency, but not by high concentrations of epidermal growth factor and human growth hormone, chemically unrelated polypeptides 125I-labeled IGF-I binding to patient's cells was decreased by approximately 75%, whereas binding of epidermal growth factor to its cell surface receptors was unaffected. Computer curve-fitting of untransformed equilibrium binding data suggests that the decreased binding resulted from a decreased Ka for IGF-I. The ability of the patient's IGF-I receptor to recognize insulin also appears to be altered. Impaired IGF-I binding by the leprechaun patient's fibroblasts may contribute to the abnormal biological response to insulinlike growth factors observed in vitro and to the in utero growth retardation.

Update on Anti-Saccharomyces cerevisiae antibodies, anti-nuclear associated anti-neutrophil antibodies and antibodies to exocrine pancreas detected by indirect immunofluorescence as biomarkers in chronic inflammatory bowel diseases: results of a multicenter study.

AIM: Anti-Saccharomyces cerevisiae antibodies (ASCA), anti-nuclear associated anti-neutrophil antibodies (NANA) and antibodies to exocrine pancreas (PAB), are serological tools for discriminating Crohn's disease (CrD) and ulcerative colitis (UC). Like CrD, coeliac disease (CoD) is an inflammatory bowel disease (IBD) associated with (auto) antibodies. Performing a multicenter study we primarily aimed to determine the performance of ASCA, NANA and PAB tests for IBD diagnosis in children and adults, and secondarily to evaluate the prevalence of these markers in CoD. METHODS: Sera of 109 patients with CrD, 78 with UC, 45 with CoD and 50 healthy blood donors were retrospectively included. ASCA, NANA and PAB were detected by indirect immunofluorescence (IIF). RESULTS: ASCA+/NANA- profile displayed a positive predictive value of 94.2% for CrD. Detection of ASCA was correlated with a more severe clinical profile of CrD and treatment of the disease did not influence their serum levels. ASCA positivity was found in 37.9% of active CoD. PAB were found in 36.7% CrD and 13.3% CoD patients and were not correlated with clinical features of CrD, except with an early onset of the disease. Fifteen CrD patients were ASCA negative and PAB positive. CONCLUSION: ASCA and PAB detected by IIF are specific markers for CrD although their presence does not rule out a possible active CoD. The combination of ASCA, NANA and PAB tests improves the sensitivity of immunological markers for CrD. Repeating ASCA, NANA, and PAB testing during the course of CrD has no clinical value.

Anti-pm/scl antibodies in connective tissue disease: Clinical and biological assessment of 14 patients.

INTRODUCTION: Anti-PM/Scl antibodies (Anti-PM/Scl) represent a rarely encountered type of antinuclear antibodies. They have mainly been reported in association with idiopathic inflammatory myositis - systemic sclerosis overlap syndromes (also called scleromyositis or sclerodermatomyositis) but also with polymyositis, dermatomyositis and systemic sclerosis without features of overlap syndromes. Studies concerning characteristics of patients with anti-PM/SCl are rare and include small numbers of patients. PATIENTS AND METHODS: Retrospective review of clinical and biological characteristics of 14 patients with anti-PM/Scl in two University Hospitals: one in Belgium (Erasme Hospital, Bruxelles) and one in France (Hautepierre Hospital, Strasbourg). RESULTS: Seven patients were identified in Erasme and 7 in Strasbourg: 5 with systemic sclerosis-(dermato)myositis overlap syndromes, 4 with dermatomyositis, 1 with polymyositis, 3 with systemic sclerosis, 1 with primary Sjögren's syndrome. The most frequently observed clinical characteristics (85% of patients) were: pulmonary interstitial disease and arthralgia or arthritis. No patient of our series died or developed cancer (mean follow-up:6.1 years). CONCLUSIONS: Our study failed to identify an homogeneous clinical pattern in patients with anti-PM/Scl, except for 2 characteristics shared by 85% of the patients. This lack of homogeneity is in agreement with preceding literature. We confirm the favourable prognosis associated with the presence of anti-PM/Scl, despite the high incidence of interstitial pulmonary disease. The absence of cancer associated with presence of anti-PM/Scl represents a partial explanation. Finally, we report herein the second case of primary Sjögren's syndrome associated with anti-PM/Scl.

Probably anti-Tr associated paraneoplastic cerebellar degeneration as initial presentation of a squamous cell carcinoma of the lung.

Paraneoplastic cerebellar degeneration (PCD) is the most frequent paraneoplastic syndrome affecting the brain. Until now, anti-Tr associated PCD was only seen in patients with Hodgkin's disease. We report a male patient who presented with a progressive ataxia, affecting predominantly the lower limbs and a cerebellar dysarthria. Extensive diagnostic approach initially showed no evidence of tumor. The patient was found to have anti-Tr antibodies in his serum. Fourteen months after onset of symptoms a whole body PET-scan showed a pathological focus at the right hilus of the lungs. A mediastinoscopy was performed and peribronchial node sampling was done. The anatomopathological analysis revealed a non-well differentiated squamous cell carcinoma. This is the first report about the association between an anti-Tr associated PCD and squamous cell carcinoma.

Diagnostic value of anti-F-actin antibodies in a French multicenter study.

According to international criteria, autoimmune hepatitis (AIH) type 1 is characterized by the presence of antinuclear or anti-smooth muscle antibodies (SMA) with F-actin specificity. SMA have been found in 85% of AIH patients, but are not specific to this disease, and anti-F-actin specificity is not always verified when SMA are detected. The objective of this study was to determine the diagnostic value of anti-F-actin antibodies in a large population. A multicenter study involving 12 clinical centers was performed. Patients were selected on the basis of the presence of F-actin SMA detected by indirect immunofluorescence (IIF) on rat liver-kidney-stomach sections and was confirmed by IIF on Hep2 cells treated with colchicine, or F-actin dot-blot. The clinical status of patients was determined from their medical records. One hundred sixty-eight patients were included: 76% women, 24% men; mean age of 45 years (range, 2-88 years), with a bimodal age distribution. Sixty percent had AIH type 1, and 40% had another disease. In the group of women younger than 25 years, 90% had AIH type 1. Other pathologies associated with antiactin were other liver diseases (19%), including viral hepatitis C (7%), and non-liver diseases (21%), including connective tissue diseases (12%). Antibody titers were higher in AIH than in other diseases. Antiactin antibodies are of major diagnostic value in AIH, especially in young women; they may be found in other disease settings, but mostly at low levels.

Evidence for two species of insulin-like growth factor II (IGF II and "big" IGF II) in human spinal fluid.

Human serum contains the somatomedins, insulin-like growth factor I and II (IGF I and II). In spinal fluid, however, only IGF II was found in measurable and significant amounts. In addition, an IGF II of larger mass could be detected by a radioimmunoassay for IGF II. This "big" IGF II is biologically active and has an apparent molecular weight of 9000.

Insulin-like growth factor I/somatomedin C (IGF-I/Sm C): comparison of natural, solid phase synthetic and recombinant DNA analog peptides in two radioligand assays.

Investigation of the biologic activity of Insulin-like Growth Factor I/Somatomedin C (IGF-I/Sm C) has been hampered by the scarcity of purified material. The synthesis of this molecule by the solid phase procedure and an analog of IGF-I/Sm C by recombinant DNA technology offers promise that studies of the biologic activity of IGF-I/Sm C will soon be possible. We have found that natural IGF-I/Sm C and the two synthetic peptides behave similarly in two radioligand systems, providing evidence that these molecules possess the requisite structural integrity for use in such biological studies.

Interactions of insulin-like growth factors I and II and multiplication-stimulating activity with receptors and serum carrier proteins.

Insulin-like growth factors (IGFs) I and II, purified from human plasma, and multiplication-stimulating activity (MSA), purified from media conditioned by the BRL 3A rat liver cell line, are polypeptides with similar biological and biochemical properties. We have compared the interaction of 125I-labeled and unlabeled MSA, IGF-I, and IGF-II with four intact cell or cell membrane preparations previously shown to possess MSA receptors: rat liver plasma membranes, chick embryo fibroblasts, human fibroblasts, and BRL 3A2 cells. In each case, specific binding of 125I-labeled IGF-I and IGF-II was demonstrated. With each 125I-labeled peptide, significant inhibition of binding and parallel dose-response curves were observed with unlabeled IGF-I, IGF-II, and MSA. Striking differences were noted, however, in the relative potencies of the unlabeled peptides as competitive inhibitors of binding. We conclude that the different specificities of binding inhibition reflect a significant heterogeneity among IGF receptors. A similar heterogeneity appears to occur among somatomedin carrier proteins in rat and human sera.

Interactions of a monoclonal antibody to the insulin receptor with receptors for insulin-like growth factors.

A monoclonal antibody to the human insulin receptor was tested for its ability to inhibit the binding of 125I-insulin-like growth factor I (IGF-I) and 125I-insulin-like growth factor II (IGF-II) to their receptors in human placenta membranes and cultured human IM-9 lymphocytes. In both placenta membranes and IM-9 cells, the antibody progressively inhibited the binding of 125I-IGF-I to its receptor with a potency that was 300-fold less than its ability to inhibit the binding of 125I-insulin to its own receptor. In contrast, in human placenta membranes, this antibody inhibited the binding of 125I-IGF-II to its receptor only slightly. These studies indicate, therefore, that this monoclonal antibody binds preferentially to the insulin receptor but also crossreacts to a lesser extent with the IGF-I receptor.

Monoclonal antibodies directed to human insulin-like growth factor I (IGF I). Use for radioimmunoassay and immunopurification of IGF.

Mouse hybridomas secreting antibodies to human insulin-like growth factor I (IGF I) were produced by fusion of spleen cells of hyperimmunised mice with FO mouse-myeloma cells. Eight clones producing antibodies against human IGF I have been isolated, two of which have been characterised. One was used in a radioimmunoassay, the other for immunopurification of IGF.

Long-term cultivation of cryopreserved human fetal brain cells in a chemically defined medium.

Conditions for long-term cultivation of human fetal brain cells in a chemically defined medium were established using cryopreserved brain fragments obtained from legal abortions. Tissue of the same gestational age was pooled and the cells cultured in a fully defined medium containing insulin-like growth factors (IGF I and II). Primary cultures were kept for 2-4 weeks and secondary or tertiary cultures could be maintained for 3 months. The cultures were characterized by morphological, electrophysiological and biochemical methods. Glial cells were predominant during the first two weeks of culture. In later stages of cultivation, glial cells diminished in number and most cells were neuronal. Voltage-dependent Na+ channels were recorded from neurons. Biochemical studies indicated that the fetal brain cells contained and secreted immunoreactive somatostatin as well as the tachykinins, substance P and neurokinin A. Cultures grown in IGF II- or nerve growth factor-containing medium expressed increased choline acetyltransferase activity.

Evidence for the presence of specific receptors for insulin-like growth factors 1 (IGE-1) and 2 (IGF-2) and insulin throughout the adult human brain.

The present study examines adult human brain tissue for the presence of receptors for insulin-like growth factors (IGFs) 1 and 2 and insulin. Binding sites for all hormones were widely distributed throughout the brain removed at autopsy, with the highest specific binding being found in the various cortical regions. Cross-reaction studies performed on frontal lobe biopsy material indicated specific binding sites for IGF-1 and insulin whereas iodinated IGF-2 was equally displaced by IGF-1 and IGF-2, suggesting the presence of an additional IGF-2-like binding site in the adult brain.

Autoantibodies and human immunodeficiency viruses infection: a case-control study.

OBJECTIVE: To determine the prevalence of organ-specific and non-specific autoantibodies in HIV-infected patients. DESIGN: A multicentric collaborative case-control study including 105 HIV patients and 100 sex- and age-matched HIV-negative healthy volunteers. METHODS: Antinuclear, anti-ds DNA, anti-histone, anti-Sm, rheumatoid factor(IgM), anti-beta 2 glycoprotein 1, antineutrophil cytoplasmic, anti-LKM1, anti-LCA1, anti-gastric parietal cell, antiplatelet, anti-intermediate filament, anti-mitotic spindle apparatus, anti-Golgi, anti-ribosome and anti-thyroid autoantibodies were screened in six European laboratories. RESULTS: Only IgG and IgM anticardiolipin, IgG antiplatelet, anti-smooth muscle and anti-thyroglobulin antibodies were statistically more frequent in HIV patients. There was no correlation with the numbers of CD4+ cells except in the case of anti-smooth muscle antibodies. We were unable to find specific autoantibodies such as anti-ds DNA, anti-Sm, AMA, anti-LKM1, anti-LCA1 or anti-beta 2 GP1 antibodies in these patients. CONCLUSIONS: Our results indicate that the autoantibody profile of HIV infections is comparable to those of other chronic viral infections. HIV does not seem to be more autoimmunogenic than other viruses.

First clinical results with Enzymun-Test for free PSA.

BACKGROUND: Prostate Specific Antigen (PSA) is widely used for the detection and monitoring of prostate cancer (CAP) but PSA is elevated in many patients with benign prostatic hyperplasia (BPH). The measurement of free PSA may improve the discrimination between CAP and BPH. MATERIAL AND METHODS: Free PSA (F-PSA) and total PSA (T-PSA) were measured using kits based on the Enzymun-Test principle. The patient population was composed of 38 untreated CAP patients, 76 BPH patients and 29 prostatitis patients. RESULTS: At cut-off levels of 0.15 for the F-PSA/T-PSA ratio and 10 ng/ml for T-PSA the specificity and sensitivity for detecting CAP were respectively 87% and 84% for F-PSA/T-PSA ratio and 80% and 63% for T-PSA. CONCLUSION: The F-PSA/T-PSA ratio is more powerful at discriminating between CAP and BPH than T-PSA alone and may contribute to a reduction in unnecessary invasive techniques.

Electron microscopy proves Jo-1 antigen to be predominantly cytoplasmic but also nuclear.

The Jo-1 antigen is a specific marker for autoimmune myositis with an excellent correlation with associated interstitial lung disease. Using an electron microscopy immunogold technique, we were able to show that the antigen was predominantly cytoplasmic.

[The importance of the thickness of the bone in osteocartilaginous autografts of the rabbit knee]. / Rôle de l'épaisseur des greffons dans l'autotransplantation ostéocartilagineuse du genou chez le lapin.

This experimental study is complementary to the clinical series of cartilaginous autografts in the knee for medial condylar necrosis. The aim was to determine the viability of the articular cartilage in a series of grafts with variable thickness of the underlying spongy bone.The study was done on 36 adult rabbits and the cartilage was studied by biochemical, histochemical and ultrastructural methods. The results are conclusive. The earliest abnormal signs in the first few weeks affect the thinnest grafts of 4 mm whereas the 12 mm thickness grafts hardly show any lesions.It is therefore possible to use large autogenic grafts for osteocartilaginous defects provided the proportion between the area of the articular surface and the underlying spongy bone of the graft is at least 1/4. Under these circumstances, cartilaginous deterioration will be avoided and reduce long term degeneration.

[Clinical significance of antiribosomal antibodies. Study Group on Autoimmunity (GEAI)]. / Signification clinique des anticorps antiribosomes. Groupe d'étude auto-immunité (GEAI).

PURPOSE: Autoantibodies directed against the ribosomal P proteins, P0, P1 and P2 (anti-P), have been related to lupus-related psychosis and/or depression. The diagnostic value of antibodies directed against other ribosomal proteins or 28S RNA (anti-no-P) remains unknown. A multicenter study including ten centers belonging to the study group for autoimmune diseases (GEAI) was conducted in order to determine the diagnostic value of anti-P and anti-no-P antibodies in a large population of patients. METHODS: The patients were selected on the basis of the presence of serum anti-ribosomal antibodies detected by indirect immunofluorescence (IF) on rat liver/kidney/stomach/pancreas sections and human HEp2 cells. The clinical course of all patients was studied using a predetermined survey. The specificity of anti-P antibodies were determined by Western blot. RESULTS: Anti-ribosomal antibodies were found in 82 patients. Fifty-five of them had systemic lupus erythematosus and 27 had another disease. Only 54% of the anti-ribosomal antibodies detected by IF were anti-P and were found in 69% of the patients with systemic lupus erythematosus. Anti-no-P antibodies (46%) were preferably detected in patients who suffered from another disease (78%). In patients with systemic lupus erythematosus, neurological and psychiatric disorders were more frequent in the no-P group (47% vs. 16%, P < 0.01) than arthritis, which was found more frequently in the P group (78% vs. 53%, P < 0.05). CONCLUSION: Anti P antibodies do not constitute a specific diagnostic marker of systemic lupus erythematosus, and lupus-related neuropsychiatric disorders would be preferably associated with the presence of anti no-P antibodies.

[The neuropathies of IgM monoclonal gammopathies]. / Les neuropathies des gammapathies monoclonales a IgM.

A peripheral polyneuropathy is often associated with an IgM monoclonal gammapathy. The monoclonal protein often binds to carbohydrate epitopes on glycoproteins and/or glycolipids of the human peripheral nerve. The clinical syndrome is related to the antigen-specificity of the IgM protein. Detection of anti-myelin antibodies and further characterization of their immunogenic specificity provide an important aid in the differential diagnosis of late-onset chronic polyneuropathies.

Production and characterization of monoclonal antibodies directed against high and low molecular weight kininogens.

HMWK and LMWK were purified from human plasma by ion exchange and affinity chromatography and used to raise anti-kininogen monoclonal antibodies. The Ig class and affinity of these Mab's that are directed at the heavy chain of the kininogens, were determined. Plasma samples of two patients, one with acquired C1-inhibitor deficiency and angioedema and one with idiopathic angioedema were analized by immunoblotting with these Mab's. Both were found to have cleaved HMWK during clinical attacks.