PspK of Streptococcus pneumoniae increases adherence to epithelial cells and enhances nasopharyngeal colonization.

Streptococcus pneumoniae (the pneumococcus) colonizes the human nasopharynx and can cause invasive disease aided by the pneumococcal capsule. Group II nontypeable S. pneumoniae (NTSp) lacks a polysaccharide capsule, and a subgroup of NTSp carriage isolates has been found to have a novel gene, pneumococcal surface protein K (pspK), which replaces the capsule locus. A recent rise in the number of NTSp isolates colonizing the human nasopharynx has been observed, but the colonization factors of NTSp have not been well studied. PspK has been shown to play a role in mouse colonization. We therefore examined PspK-mediated immune evasion along with adherence to host cells and colonization. PspK bound human secretory immunoglobulin A (sIgA) but not the complement regulator factor H and did not decrease C3b deposition on the pneumococcal surface. PspK increased binding of pneumococci to epithelial cells and enhanced pneumococcal colonization independently of the genetic background. Understanding how NTSp colonizes and survives within the nasopharynx is important due to the increase in NTSp carriage. Our data suggest that PspK may aid in the persistence of NTSp within the nasopharynx but is not involved in invasion.

Purified lymphocyte function-associated antigen 3 binds to CD2 and mediates T lymphocyte adhesion.

CD2 is a T lymphocyte glycoprotein that functions in adhesion of T lymphocytes and also as a putative receptor for activation signals. Functional data suggest that LFA-3, a widely distributed cell surface glycoprotein, may be the biological ligand of CD2. We have purified LFA-3 from human erythrocytes and characterized the purified protein functionally. LFA-3 bound specifically to CD2+ cells, and this binding was inhibited by CD2 mAb. Conversely, purified LFA-3 inhibited binding of CD2 mAb to cells, and the concentration required for this effect suggests that LFA-3 half-saturated CD2 at 1-5 nM LFA-3. Purified LFA-3 inhibited rosetting of human and sheep erythrocytes with CD2+ T lymphoma cells and T lymphocytes, and mediated aggregation of a CD2+ T lymphoma cell line. Purified LFA-3 reconstituted into planar membranes mediated efficient CD2-dependent adhesion of T lymphoblasts. These data demonstrate that LFA-3 is a ligand for CD2 and that LFA-3 can mediate T lymphocyte adhesion.

Rosetting of activated human T lymphocytes with autologous erythrocytes. Definition of the receptor and ligand molecules as CD2 and lymphocyte function-associated antigen 3 (LFA-3).

CD2, also known as LFA-2, T11, and the E rosette receptor, is a T lymphocyte surface protein functionally important in adhesion to target cells and T cell triggering. LFA-3 is a widely distributed cell surface protein that functions in adhesion on target cells. We find that LFA-3 is expressed on human E, and that CD2 is a receptor for LFA-3 that mediates T cell adhesion to human E. Pretreatment of T lymphocytes with CD2 mAb or of E with LFA-3 mAb inhibits rosetting. Purified CD2 molecules bind to human E and inhibit rosetting. 125I-CD2 binding to E is inhibited by LFA-3 mAb; reciprocally, binding of LFA-3 mAb to human E is inhibited by pretreatment with purified CD2. Higher concentrations of CD2 aggregate human E; aggregation is inhibited by mAb to LFA-3.

Primary structure of lymphocyte function-associated antigen 3 (LFA-3). The ligand of the T lymphocyte CD2 glycoprotein.

We have isolated the cDNA for human lymphocyte function-associated antigen 3 (LFA-3), the ligand of the T lymphocyte CD2 molecule. The identity of the clones was established by comparison of the deduced amino acid sequence to the LFA-3 NH2-terminal and tryptic peptide sequences. The cDNA defines a mature protein of 222 amino acids that structurally resembles typical membrane-anchored proteins. An extracellular domain with six N-linked glycosylation sites is followed by a hydrophobic putative transmembrane region and a short cytoplasmic domain. The mature glycoprotein is estimated to be 44-68% carbohydrate. Southern blots of human genomic DNA indicate that only one gene codes for human LFA-3. Northern blot analysis demonstrates that the LFA-3 mRNA of 1.3 kb is widely distributed in human tissues and cell lines.

Retail refrigerated probiotic foods and their association with evidence of health benefits.

Probiotic usage in food is widespread and growing. The objective of this study was to determine the percentage of probiotic food products sold in the refrigerated section of retail grocery stores in the Washington DC area that we could link to evidence of any health benefit. We surveyed refrigerated sections of eight large grocery stores representing five national chains for probiotic products. Based on declared probiotic composition (strain and count) for each product, we searched PubMed for controlled trials that provided evidence of any health benefit. Our assessment showed that 49% (22 out of 45 distinct probiotic foods) could be linked to evidence supporting a health benefit. All products indicating strain composition could be linked to evidence. Our study suggests that consumers have a reasonable likelihood of purchasing a refrigerated probiotic food with evidence, but room for improvement exists.

Activation of terminal components of complement in patients with Guillain-Barré syndrome and other demyelinating neuropathies.

In the present study, the role of antiperipheral nerve myelin antibody (anti-PNM Ab) in demyelination by generating the terminal attack complex (C5b-9) of complement was explored in patients with Guillain-Barré syndrome (GBS) and other demyelinating neuropathies. The presence in serum of SC5b-9, an inactive C5b-9 containing S protein, was assessed quantitatively by enzyme-linked immunosorbent assay using an antibody (Ab) to neoantigens expressed on C9 when complexed with C5b-8 or after tubular polymerization. SC5b-9 was detected in all 19 GBS, four patients with paraprotein-associated neuropathy and five of six patients with chronic recurrent polyneuritis. No SC5b-9 was detected in 10 normal controls. Kinetic studies from six GBS patients showed the highest values of SC5b-9 on the 3rd to 5th d of admission; in contrast, the anti-PNM Ab were highest on the day of admission. Anti-PNM Ab fell rapidly to very low levels by the 15th to 20th d. SC5b-9 declined with similar kinetics to undetectable levels by the 30th d. Levels of Ab and SC5b-9 did not quantitatively correlate with soluble immune complexes in these patients' serum. Membrane-bound C5b-9 was also detected by immunohistochemistry in the peripheral nerves from a GBS patient. These results, which show a relationship between levels of complement-fixing anti-PNM Ab and the tissue-damaging C5b-9 complex, suggest that peripheral nerve myelin may serve as the target for Ab-mediated complement attack.

Blocking the receptor for C5a in patients with rheumatoid arthritis does not reduce synovial inflammation.

OBJECTIVES: All complement pathways lead to the formation of C5a, which is believed to contribute to the influx and activation of C5a-receptor (C5aR) bearing cells into the joints of patients with rheumatoid arthritis (RA). Studies in animal models of RA have suggested therapeutic potential of C5aR blockade. In this study, we examined the effects of the C5aR blockade on synovial inflammation in RA patients. METHODS: We performed a double-blind, placebo-controlled study using an orally administered C5aR-antagonist. Twenty-one patients with active RA were randomized 2:1 to treatment with a C5aR-antagonist AcF- (OpdChaWR) (PMX53) vs placebo for 28 days. Serum concentrations of PMX53 were determined. Synovial tissue was obtained at baseline and after 28 days of treatment for pharmacodynamic analysis using immunohistochemistry and digital image analysis. RESULTS: All patients completed the study. Areas under the curve (AUCs) of PMX53 in patients' blood samples showed a mean of 40.8 nmol h/l. There was neither decrease in cell infiltration, nor changes in key biomarkers associated with clinical efficacy after active treatment. In addition, there was no trend towards clinical improvement in the C5aR-antagonist-treated group compared with placebo nor was there a correlation between the AUC and clinical response. CONCLUSIONS: Treatment with PMX53 did not result in a reduction of synovial inflammation despite reaching serum levels of PMX53 that block C5aR-mediated cell activation in vitro. The data suggest that C5aR blockade does not result in reduced synovial inflammation in RA patients.

Evaluating feasibility of an automated 3-dimensional scanner using Raman spectroscopy for intraoperative breast margin assessment.

Breast conserving surgery is the preferred treatment for women diagnosed with early stage invasive breast cancer. To ensure successful breast conserving surgeries, efficient tumour margin resection is required for minimizing tumour recurrence. Currently surgeons rely on touch preparation cytology or frozen section analysis to assess tumour margin status intraoperatively. These techniques have suboptimal accuracy and are time-consuming. Tumour margin status is eventually confirmed using postoperative histopathology that takes several days. Thus, there is a need for a real-time, accurate, automated guidance tool that can be used during tumour resection intraoperatively to assure complete tumour removal in a single procedure. In this paper, we evaluate feasibility of a 3-dimensional scanner that relies on Raman Spectroscopy to assess the entire margins of a resected specimen within clinically feasible time. We initially tested this device on a phantom sample that simulated positive tumour margins. This device first scans the margins of the sample and then depicts the margin status in relation to an automatically reconstructed image of the phantom sample. The device was further investigated on breast tissues excised from prophylactic mastectomy specimens. Our findings demonstrate immense potential of this device for automated breast tumour margin assessment to minimise repeat invasive surgeries.

Role of N-methylolpentamethylmelamine in the metabolic activation of hexamethylmelamine.

Hexamethylmelamine (HMM) is metabolized by rat hepatic microsomal preparations to reactive species which covalently bind to microsomal protein and to calf thymus DNA added to microsomal incubation mixtures. Covalent binding to macromolecules is dependent on the presence of molecular oxygen and reduced nicotinamide adenine dinucleotide phosphate and is catalyzed by cytochrome P-450 monooxygenases. Reduced nicotinamide adenine dinucleotide-dependent covalent binding of [methyl-14C]HMM to microsomal protein is greater than that of [ring-14C]HMM. Reduced nicotinamide adenine dinucleotide phosphate-dependent covalent binding of [ring-14C]HMM and [methyl-14C]HMM to calf thymus DNA added to microsomal incubation mixtures are approximately equal. The [ring-14C]-labeled carbinolamine intermediate in HMM demethylation, N-methylolpentamethylmelamine, covalently binds to microsomal protein and, to a much greater extent, to calf thymus DNA.

Molecular pathways of adhesion in spontaneous rosetting of T-lymphocytes to the Hodgkin's cell line L428.

Spontaneous rosetting of T-lymphocytes to Reed-Sternberg cells has been observed both in vitro and in vivo but its molecular mechanism has not been defined. We have investigated such rosetting using the Hodgkin's cell line L428. L428 expresses high levels of LFA-3 and ICAM-1, both of which are ligands for T-cell adhesion. Monoclonal antibody inhibition of spontaneous rosetting indicated that it is not dependent on the T-cell receptor complex but is largely mediated by interaction of T-cell CD2 (T11/E-rosette receptor) with its ligand LFA-3 on L428 cells. Studies using an alternate assay of adhesion (conjugate formation) confirm the roles of CD2/LFA-3 and also implicate a second mode of binding via LFA-1 on T-cells to ICAM-1 on L428. These data explain the previously reported finding of T-cell rosetting with Reed-Sternberg cells as an exaggeration of normal antigen-independent T-cell adhesion.

Alterations in HLA-DP and HLA-DQ antigen frequency in patients with dermatitis herpetiformis.

Dermatitis herpetiformis (DH) is associated with a markedly increased frequency of the HLA class II antigens DR3 and DQw2. To investigate a possible role of HLA-DP (or closely associated genes) in the pathogenesis of DH as well as to confirm the previously described alterations of HLA-DR3 and HLA-DQw2 antigen frequency, we have typed 43 patients with DH for HLA-DP, HLA-DQ, and HLA-DR antigens. All patients with DH had typical clinical and histologic features, as well as granular deposits of IgA at the dermal-epidermal junction by direct immunofluorescence. HLA-DR3 was expressed in 41 of 43 (95%) DH patients, whereas HLA-DQw2 was expressed in all 43 (100%). The overall distribution of HLA-DP antigens in patients with DH was significantly different from that seen in all controls and in HLA-DR3 and HLA-DQw2 controls (p less than 0.02). Examination of the frequency of individual DP antigens revealed that HLA-DPw1 was increased (42% of patients with DH vs 11% of all controls and 26% of DR3 positive controls), but this increase was not statistically greater than that expected due to the disequilibrium linkage of DPw1 with DR3/DQw2. Patients with DH, however, did have a statistically significant decreased frequency of DPw2 (14% of patients vs 31% of all controls and 41% of DR3 positive controls) (pc less than 0.05). Studies of three informative families demonstrated that the DPw2 genes of the DH patients were not present on the haplotype thought to carry a DH susceptibility gene (HLA-A1, HLA-B8, HLA-DR3, HLA-DQw2). A role of HLA-DP region genes in the pathogenesis of DH is further suggested by the observation that HLA-DPw1 was expressed in 82% (9 of 11) of DH patients with IgA antibodies against dietary antigens as compared with only 33% (4 of 12) of patients without IgA antibodies. HLA-DP genes or genes closely linked to them may be important in DH either as markers of the disease haplotype or by direct involvement in its pathogenesis.

Beta-carotene's effects on serum lipoproteins and immunologic indices in humans.

Doses of beta-carotene for cancer-prevention trials have been chosen based on epidemiologic data. Mechanisms of the putative antineoplastic effects by beta-carotene are unknown but may involve modulation of the immune system. We measured plasma carotenoid concentrations and selected immunologic indices at baseline and at 2 and 4 wk in 50 healthy humans (5 groups of 10 each) ingesting 0, 15, 45, 180, or 300 mg beta-carotene/d for 1 mo in this randomized placebo-controlled, open-label, parallel study. Plasma beta-carotene concentrations were markedly increased by 2 wk and were correlated with dose. Beta-carotene concentrations plateaued between 2 and 4 wk except for the 300-mg group. Thus, we developed a dose-concentration curve to optimize beta-carotene-dose selection to achieve target plasma concentrations. We were unable to identify any effects of beta-carotene ingestion on the immunologic indices studied, but modest increases in high-density-lipoprotein cholesterol were observed in all beta-carotene-treated groups.

Phage resistance in lactic acid bacteria.

The interactions between lactic acid bacteria and their phages are commercially significant. Current research has focused on the elucidation of the mechanisms and genetics of phage resistance. Phage resistance genes have been linked to plasmid DNA for Streptococcus lactis and Streptococcus cremoris, and preliminary studies suggest the operation of mechanisms such as the prevention of phage adsorption, restriction/modification, and abortive infection. Some phage resistance plasmids can be conjugally transferred, providing a means of dissemination among phage-sensitive strains for the construction of phage-resistant starter cultures.

Preparation of large numbers of highly purified normodense human eosinophils from leukapheresis.

Methods have been developed for the preparation of large numbers of virtually pure, normodense eosinophils from the peripheral blood of normal human volunteers by means of leukapheresis. The purification depends on the sequential removal of mononuclear cells using a one-step discontinuous density gradient, lysis of erythrocytes, enrichment of eosinophils by centrifugation through discontinuous Percoll gradients and, finally, passive selection of the eosinophils by removal of the remaining polymorphonuclear neutrophils with a monoclonal antibody to CD16. The purity of the isolated eosinophils was consistently in excess of 95%. Recovery into the normodense eosinophil fraction ranged between 10 and 87% (average 31.6 +/- 4.2) and recovery during the monoclonal antibody step averaged 80.3 +/- 8.6%. These methods have made it possible, for the first time, to isolate 2-20 x 10(7) virtually pure normodense eosinophils from the peripheral blood of a single donor for further biochemical or pharmacological experimentation.

Pitfalls in the quantitative estimation of the secretion of granule proteins by eosinophils.

The secretion of preformed granule proteins by eosinophils is an important correlate of eosinophil activation. However, a review of the literature reveals large disparities in the amounts of these substances which were reportedly secreted when eosinophils were activated. In the present study we report that our attempts to quantitate the secretion of eosinophil peroxidase and eosinophil-derived neurotoxin from activated eosinophils by measuring these substances in the incubation supernatants were uniformly unsuccessful. We found that, once they were secreted, both eosinophil peroxidase and eosinophil-derived neurotoxin were promptly lost to assay and presumably destroyed. Thus the measurement of the difference in the concentration of these substances in eosinophils prior to and after activation, revealed that as much as 65% of the eosinophil-derived neurotoxin and 62% of the peroxidase in the eosinophils were lost to assay during activation of the cells whereas the largest amount of these substances which could be measured in the incubation supernatants never exceeded 2%. Evidence is presented that the destruction of eosinophil-derived neurotoxin must occur prior to the release of this substance into the medium. Attempts to inhibit the destruction of eosinophil peroxidase and of eosinophil-derived neurotoxin by incorporating various inhibitors into the incubations were unsuccessful. These results emphasize the need to monitor the overall recoveries of secreted products from activated eosinophils and suggest that meaningful estimates of the secretion of these granule proteins from activated eosinophils can only be obtained by measuring the residual content of these substances in eosinophils after they have been activated and comparing these values to the contents of eosinophils prior to activation.

Quantitation of activation of the human terminal complement pathway by ELISA.

We have devised an enzyme-linked immunosorbent assay (ELISA) to quantitate fluid phase terminal complement pathway activation. Upon activation to form C5b-9, terminal complement components express neoantigens not present in the unassembled individual components. Expression of one of these neoantigens occurs at the step of C9 activation. C9 neoantigen is present in fluid phase SC5b-9 complexes, membrane-bound MC5b-9 complexes, and in in vitro polymerized C9. Under physiologic conditions, the presence of C9 neoantigen indicates that the terminal complement pathway is activated through the terminal component C9. In our assay for C9 neoantigen, we used rabbit antiserum to polymerized C9 rendered specific for C9 neoantigenic determinants by serial absorption with human serum, human C9, and other terminal complement components bound to Sepharose. Using the IgG from this antiserum, we devised a sandwich ELISA to bind SC5b-9 from solution onto polystyrene plates. The ELISA plates were developed with the use of goat antiserum to native C9 epitopes followed by a swine anti-goat IgG-alkaline phosphatase conjugate. Quantitation of SC5b-9 in solution was performed by comparing sample OD to a standard curve generated with human SC5b-9 that was purified from zymosan-activated serum. The assay was sensitive to as little as 100 ng of SC5b-9/ml and should be useful for screening plasma, serum, cerebrospinal fluid, or other biological fluids for the presence of terminal complement pathway activation.

Serum complement activation in central nervous system disease in Sjögren's syndrome.

PURPOSE: Central nervous system disease and vasculitis are extraglandular manifestations of Sjögren's syndrome. In our experience, central nervous system disease develops in approximately 70 percent of patients with Sjögren's syndrome and biopsy documented peripheral vasculitis. In order to further investigate the pathogenesis of central nervous system disease and its relationship to peripheral vasculitis in Sjögren's syndrome, we examined sera of patients with Sjögren's syndrome with and without focal central nervous system involvement for evidence of terminal complement pathway activation. PATIENTS AND METHODS: Patients were classified as having active focal central nervous system involvement only when they had focal neurologic deficits on physical examination, plus at least one abnormal neurodiagnostic test result. Two thirds of these patients also had cognitive or psychiatric dysfunction. Patients were classified as having peripheral vasculitis if they had clinical and histopathologic documentation of vascular inflammation. Serum SC5b-9 was measured by a sensitive enzyme-linked immunoabsorbent assay. Total hemolytic complement assay, measurement of serum C3 and C4 by radial immunodiffusion, and determination of immune complexes were performed. RESULTS: Fluid-phase terminal complement complexes (SC5b-9) were detected in the sera of 25 of 30 (83 percent) patients with focal central nervous system involvement, but in only seven of 21 (33 percent) patients with Sjögren's syndrome without focal central nervous system disease (p = 0.00084 by Yates' chi-square analysis). Four of these seven patients without focal central nervous system disease, but who had serum SC5b-9, had psychiatric or cognitive dysfunction. SC5b-9 was also detected in sera from 14 of 15 (93 percent) patients with active biopsy-documented peripheral vasculitis in contrast to 18 of 36 (50 percent) patients without clinical evidence of peripheral vasculitis (p = 0.0094). Serum SC5b-9 was a more sensitive indicator of complement activation than circulating immune complex or complement assays. CONCLUSION: These findings suggest that terminal complement activation may participate in the pathophysiology of both central nervous system and peripheral vasculitis in Sjögren's syndrome. Serum SC5b-9 appears to be a useful diagnostic indicator of vascular inflammation in Sjögren's syndrome and appears to identify those patients at risk for central nervous system complications.

Prevention of colonic preneoplastic lesions by the probiotic Lactobacillus acidophilus NCFMTM in F344 rats.

The experiments described here were aimed at developing novel probiotic strains that may aid in the reduction of colon cancer risk. We assessed the potential anticancer properties of Lactobacillus acidophilus NCFMTM in male F344 rats using inhibition of the formation of azoxymethane (AOM)-induced aberrant crypt foci (ACF) in the colon as the measure of preventive efficacy. At 6 weeks of age, groups of rats were fed the experimental diets containing 0, 2% or 4% lyophilized cultures of L. acidophilus NCFMTM. At 7 weeks of age, all animals in each dietary group, except the vehicle-treated rats, were s.c. injected with AOM (15 mg/kg body weight) once weekly for two weeks. The vehicle-treated groups were given s.c. injections of normal saline. All rats were necropsied 10 weeks after the last AOM injection and ACF in formalin-fixed, methylene blue-stained colonic tissues were counted under the light microscope. The contents of the cecum were analyzed for bacterial beta-glucuronidase activity. Diet supplementation with the probiotic strain NCFMTM significantly suppressed AOM-induction of colonic ACF, in terms of total number, as well as crypt multiplicity and number of ACF/cm2 colon (P<0.01 - 0.001). NCFMTM inhibited AOM-induced colonic ACF formation in a dose-dependent manner (P<0.01). A significant dose-dependent reduction of cecal beta-glucuronidase activities was observed in the rats fed 2% (P<0.04) and 4% (P<0.0001) NCFMTM. These results suggest that Lactobacillus acidophilus NCFMTM may potentially prevent colon cancer development. Further studies are warranted to determine the full potential of this probiotic strain in preclinical efficacy studies.

Distinction between dysplasia-associated lesion or mass (DALM) and adenoma in patients with ulcerative colitis.

Polyps with epithelial dysplasia in ulcerative colitis (UC) represent either dysplasia-associated lesions or masses (DALMs) or sporadic adenomas. DALMs are frequently associated with associated carcinoma and are an indication for colectomy. Removal of the polyp is treatment of choice for sporadic adenomas. Differentiating between these 2 lesions is not always easy. The goal of this study was to distinguish DALMs from adenomas in patients with UC on a genetic basis. We evaluated genetic alterations in DALMs and compared them with a previously published set of dysplastic polyps in patients with UC that were considered adenomas for the following reasons: (1) polyps were located outside of current active disease; (2) polyps had histological features of sporadic adenomas; and (3) patients displayed a uneventful follow-up after polypectomy (UC-adenomas). In addition, adenomas not associated with UC were studied. Genetic alterations on chromosome 3p were assessed for the markers D3S1766, D3S2409, and D3S2387. LOH with or without microsatellite instability was found in 70%, 37%, and 57% of cases of DALM, respectively. In contrast, UC-adenomas lesions exhibited genetic alterations in 8.3%, 11.7%, and 15.3% for the respective markers. Spontaneous adenomas exhibited genetic alterations in 10.5%, 7.1%, and 0% of cases, which were not significantly different from the UC-adenoma results. These results indicate that UC-adenomas are genetically and biologically similar to sporadic adenomas and that UC-adenomas may biologically represent sporadic adenomas, supporting on a genetic basis the criteria chosen to diagnose adenomas in UC. Genetic markers on chromosome 3p may be useful in the differential diagnosis between DALM and UC-adenomas.

Experience with a chimeric monoclonal anti-CD4 antibody in the treatment of refractory rheumatoid arthritis.

We have used a chimeric monoclonal anti-CD4 antibody (cM-T412) in a phase I trial involving patients with refractory RA. The objectives of this initial study were to evaluate the safety, immunogenicity, and biologic effects of cM-T412. Twenty-five patients with active refractory RA (all taking methotrexate concomitantly) were treated with incremental doses (10 to 700 mg) of cM-T412 in an open-label, escalating dose phase I trial. Levels of circulating CD4+ T-cells decreased rapidly post-infusion and remained significantly depressed even at 18 months following treatment. Repopulation of CD4+ T cells consisting of increased CD45RA+ (naive) and CD45RO+ (memory) CD4+ T-cells was observed in approximately 1/3 of the patients between day 14 and 6 months post-infusion. Proliferative responses of peripheral blood lymphocytes to mitogens and recall antigens were generally diminished following cM-T412 infusion, with mitogen responses normalizing more rapidly than responses to recall antigens. Adverse events during the first 6 months of follow-up included fever, often associated with myalgias, malaise, and asymptomatic hypotension; these symptoms were self-limited and appeared to correlate with transient elevations of interleukin-6. Negligible human antibody responses to the cM-T412 variable region were observed; indeed, only 2 patients developed transient low levels of antibodies reactive with cM-T412. Non-blinded assessment indicated that 43% of patients exhibited > or = 50% improvement in tender joint counts at 5 weeks, and 33% at 6 months post-infusion.(ABSTRACT TRUNCATED AT 250 WORDS)