[Standardization and automation of HLA B27 typing by flow cytometry: validation and comparison with microlymphocytotoxicity]. / Standardisation et automatisation du typage HLA B27 par une technique cytofluorimétrique: validation par comparaison à la microlymphocytoxicité.

One of the strongest known association between human leukocyte antigen (HLA) phenotype and disease is that of ankylosing spondylitis and HLA-B27. Thus, the determination of HLA-B27 status is an useful tool in the diagnosis of ankylosing spondylitis. To date, the 2 reference methods for HLA typing (microlymphocytotoxicity and molecular biology techniques), are costly in terms of both technician time and materials, and require a great deal of experience. In total, these techniques are not well-suited for routine application in clinical immunology laboratories. Use of flow cytometry has recently been applied for HLA-B27 typing. Nevertheless, it requires an extensive validation protocol. We developed a flow cytometry technique as standardized as possible (whole blood, automated lysing system, automated photomultiplier voltage calibration, definition of thresholds stable with time) and validated our results by comparison with microlymphocytotoxicity. In total, 326 samples were analyzed. We found 99% of concordant results between the 2 techniques, and neither false positive results nor false negative results with flow cytometry could be observed. These results illustrate the reliability of the protocol. It should be remembered that reference technique remains necessary to confirm the few results (< 1%) found in "grey zone" by flow cytometry. Standardization of flow cytometry techniques, as described in this work for HLA B27, seems to be a reasonable goal for the next decade in clinical immunology laboratories.

Two new alpha chain variants: Hb Boghé [alpha58(E7)His-->Gln, alpha2], a variant on the distal histidine, and Hb CHarolles [alpha103(G10)His-Tyr, alpha1].

The present paper reports two new alpha-globin chain variants: Hb Boghé [alpha58(E7)His-->Gln, alpha2] and Hb Charolles [alpha103(G10)His-->Tyr, alpha1]. Hb Boghé was found in a 12-month-old girl who was treated for malignant histiocytosis at 9 months of age and received a bone marrow transplant from her sister. Hb Boghé was undetectable by isoelectrofocusing and high performance liquid chromatography of hemoglobins. It was only revealed by polyacrylamide gel electrophoresis of globin chains in the presence of urea-Triton X-100 and accounted for 10% of the total hemoglobin. Hb Charolles was detected in a 46-year-old patient who presented with microcytosis and hypochromia. It was easily detected by isoelectrofocusing and high performance liquid chromatography. Hb Charolles accounted for 11% of the total hemoglobin. Characterization of the two hemoglobin variants was achieved by DNA and restriction enzyme analyses. Oxygen equilibrium curves measured on whole blood with Hb Boghé were normal. DNA sequencing revealed the association of Hb Charolles with a common mutation of the alpha2 polyadenylation site: AATAAA-->AATAAG.

Accumulation of pefloxacin in the lower respiratory tract demonstrated by bronchoalveolar lavage.

The in-vivo pulmonary disposition of pefloxacin in alveolar macrophages alveolar macrophages and in the alveolar epithelial lining fluid recovered by bronchoalveolar lavage was studied in 10 healthy volunteers. Bronchoalveolar lavage was performed either 2 or 4 h after oral intake of 800 mg of the drug. The recovered fluid was immediately centrifuged and processed for the assays. Pefloxacin was assayed by High Pressure Liquid Chromatography (HPLC) and by a microbiological method. The mean concentrations of pefloxacin assayed by HPLC were 106 +/- 11.1 mg/L in alveolar macrophages and 88.2 +/- 10 mg/L in the epithelial lining fluid, whereas the mean serum concentration was 6.67 +/- 0.47 mg/L. Therefore, pefloxacin accumulated rapidly in human alveolar macrophages. The high epithelial lining fluid concentrations may be attributed to lipophilicity of the drug and to rapid diffusion from blood, pulmonary cells and interstitium during the bronchoalveolar lavage procedure. The substantial accumulation of pefloxacin in alveolar components (alveolar macrophages and epithelial lining fluid) endorses its use in the treatment of intracellular bacterial infections such as legionellosis; for these diseases, pefloxacin represents an alternative to the macrolide antibiotics.

The effects of high molecular weight- and low molecular weight-heparins on superoxide ion production and degranulation by human polymorphonuclear leukocytes.

High molecular weight (HMW) and low molecular weight (LMW) heparins affected superoxide ion production and degranulation by polymorphonuclear leukocytes (PMNL) isolated from either chronic hemodialyzed patients or healthy controls. Low concentrations in HMW-heparin, below 1.76 aXa IU/ml for patients and 1.34 aXa IU/ml for controls, increased O2- production started by phorbol myristate acetate. High concentrations above these values decreased it. Increasing LMW-heparin concentrations constantly decreased O2- production using the same stimulus. Myeloperoxidase (MPO) released by PMNL was found to be significantly HMW- and LMW-heparins dose-dependent. The addition of calcium chloride significantly increased MPO release. Lactoferrin release was not dose-dependent of HMW- or LMW-heparins. However, an increase of the percentage of positive responses for lactoferrin release was observed in the simultaneous presence of HMW-heparin and CaCl2 compared to HMW-heparin alone. Lysozyme release was also not dose-dependent of HMW- or LMW-heparins. An increase of the percentage of positive responses for lysozyme release was observed in the presence of CaCl2 alone compared to HMW-heparin.

Specific binding between human neutrophils and heparin.

Heparin binding on polymorphonuclear leucocytes (PMNL) was characterized. Heparin binding was specific, rapid, saturable and reversible. One single class of heparin binding sites was found with a dissociation constant of 1.22 mumol/l and 7.7 x 10(6) sites per PMNL. The binding was independent of the anticoagulant activity of heparin. Heparin affinity chromatography on radio-iodinated cell lysates followed by polyacrylamide gel electrophoresis in the presence of sodium dodecylsulphate revealed a 130 kD heparin binding protein. Heparin binding was inhibited by disodium salt of ethylenediamine tetraacetic acid. Cell surface bound heparin was functionally inactive and did not affect the inactivation of thrombin by antithrombin III. Our study demonstrates that heparin interacts with PMNL by a cell-surface binding protein. These instructions could be consistent with the modifications of some PMNL functional properties in the presence of heparin.

Specific detection of monocytic lysozyme within normal and leukemic cells.

A murine monoclonal antibody against human lysozyme (AHL MoAb) was produced and tested on normal and leukemic monocytes using flow cytometry. The antibody gave a positive reactivity on normal monocytes permeabilized by saponin (82% to 98% of positive cells) and a negative reactivity on normal permeabilized neutrophils. This monocyte-specific reactivity had not been observed using a polyclonal antibody. Nevertheless, immunoblotting detected lysozyme in both monocyte and polymorphonuclear leukocyte (PMNL) lysates. The AHL MoAb, in the presence of lysozyme substrate (Micrococcus lysodeikticus cell walls), strongly inhibited the enzymatic activity. Flow cytometric analysis of leukemic cells isolated from patients suffering from different subtypes of acute myeloid leukemia (French-American-British [FAB] classification FAB M1-5) showed a highly significant positivity of FAB M5 for lysozyme compared with the other subtypes. The present results were consistent with the detection of a lysozyme epitope by AHL MoAb located near the catalytic site in monocytes. The same epitope was probably masked in PMNL granules.

Glycosyltransferase activities in normal and leukaemic monocytic cells.

Glycosyltransferase activities were measured in normal monocytes and in leukaemic monoblasts. Biosynthesis of glycosylated derivatives of dolichyl-monophosphate, which act as intermediates in glycosylation, was measured. Transfer of mannose from GDP-mannose was greatly increased in leukaemic monoblasts. Galactosyltransferase activities, using endogenous protein acceptors, were increased in leukaemic cells of the monocytic lineage compared to normal cells. No significant difference was observed on specific exogenous glycoprotein acceptors. These selective increases of some glycosyltransferase activities in normal and leukaemic monocytic cells can be correlated either with different expression of specific carbohydrate structures or with changes in glycosylation regulation.

Effects of tiaprofenic acid on interleukin 1, phospholipase A2 activity, prostaglandins, neutral protease, and collagenase activity in rheumatoid synovial fluid.

IL-1 and prostaglandin (PGE2, PGF2 alpha, TXB2) concentrations, PLA2 activity, neutral protease activity, and collagenase activity specific for types I and II collagen were determined in the SF of patients suffering from RA, before and after treatment with TA. Active and latent forms of protease and collagenases were regularly detected but were unrelated to IL-1, PLA2, and PGE2. TA induced a significant decrease in tested eicosanoids but IL-1, PLA2, and proteases were unchanged.