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Biomedical subjects

D G Williams

Publications and source records attributed to D G Williams.

At least 91 records · Page 5Linked to original sources
PubMed1988

Preparative isolation of p67, A, B, B' and D from nRNP/Sm and Sm antigens by reverse-phase chromatography. Use in a polypeptide-specific ELISA for independent quantitation of anti-nRNP and anti-Sm antibodies.

The p67 (67 kDa) and A (33 kDa) polypeptides of nRNP/Sm antigen and the B, B' (28 and 29 kda) and D (16 kDa) polypeptides of 'free' Sm antigen were isolated and used in enzyme-linked immunoadsorbent assays (ELISA) for human autoantibodies. ELISA specificity was demonstrated using monoclonal antibodies. The ELISA using HPLC-purified polypeptides was found to be more sensitive than immunoblotting for detecting antibody. 86% of sera with precipitating anti-nRNP antibodies were positive in the ELISA, as were all sera with precipitating anti-Sm antibodies. Patients with rheumatoid arthritis (RA), Sjögrens syndrome (SS) and undifferentiated connective tissue disease (UCTD) had low levels of anti-p67 with a prevalence 11.6% and 18%, respectively, whilst patients with systemic lupus erythematosus (SLE) and mixed connective tissue disease (MCTD) had high levels and prevalence rates of 55.2% and 80%, respectively. Anti-B or anti-D antibodies were detected at high levels in SLE (prevalence 30%) but were found rarely in UCTD and MCTD (prevalence 7% and 10%) and not at all in RA or SS sera.

Animals↗
PubMed1988

Improved prognosis of renal microscopic polyarteritis in recent years.

To determine if the short- and long-term prognosis of renal micropolyarteritis (including Wegener's granulomatosis) had improved in our Unit in the last 5 years compared to our previous series from 1965 to 1980, we examined data from 26 recent patients, 1981-1986. Twenty were admitted during acute phase and six after a mean of 7.1 months of disease. The acute phase showed mild to severe impairment of renal function, and renal biopsies showed necrotising glomerulitis in all acute patients with extensive crescents in 67%. Acute patients (20) were treated with 'aggressive' immunosuppression including i.v. methylprednisolone (15), plasmapheresis (seven) and cyclophosphamide (ten). Chronic immunosuppressive treatment was continued in most patients. In the 20 acute-onset patients, life survival at 2 and 5 years was 77%; four of five deaths occurred during the acute phase in aged patients with severe renal failure. The notable improvement in life and kidney survival (only one patient underwent chronic dialysis) probably resulted from greater awareness of vasculitis in general practice with early referral of patients to specialised units, and to more aggressive treatment.

Acute Disease↗
PubMed1988

Specificity of anti-Sm antibodies by ELISA for systemic lupus erythematosus: increased sensitivity of detection using purified peptide antigens.

Sm antigen was purified by immunoaffinity chromatography using a murine monoclonal anti-Sm antibody and was confirmed to be free from contaminating polypeptides. This was then used to detect anti-Sm antibodies in patients' sera by enzyme linked immunosorbent assay (ELISA). Antibodies against Sm were detected in only 9/52 (17%) patients with systemic lupus erythematosus (SLE) by immunodiffusion, but 15/52 (29%) were positive for IgG anti-Sm antibodies by ELISA. The presence of anti-Sm antibodies remained disease specific despite the increase in sensitivity of this assay and validates its potential use for clinical application. There was no correlation between the presence of anti-Sm antibodies and any clinical features of SLE. In 23 renal biopsies a membranous component to the glomerulonephritis correlated with anti-Sm antibodies (p less than 0.05). Patients from West Africa, the Carribean Islands, and Asia had a higher prevalence of anti-Sm antibodies than the local Caucasian population.

Antibody Specificity↗
PubMed1988

Relation of mesangial IgA glomerulonephritis to polymorphism of immunoglobulin heavy chain switch region.

We have investigated the switch regions of Ig heavy chain genes of patients with IgA glomerulonephritis (IgA-GN) using restriction fragment length polymorphism (RFLP) analysis. Genomic DNA from patients and controls was digested with the restriction endonuclease Sst I and transferred to nylon membranes using the Southern blot procedure and hybridized with a probe homologous to the switch region of the Ig C mu gene (S mu) which detects RFLPs in both S mu and the switch region of the Ig C alpha 1 gene (S alpha 1). A significant decrease in the frequency of the 2.6;2.1 kb heterozygous S mu phenotype was found in patients with IgA-GN (P = 0.003). With respect to the S alpha 1 region, there was a significant increase in the frequency of the 7.4 kb S alpha 1 phenotype (P = 0.002). In addition, a significant increase in the frequency of the 7.4 kb S alpha 1 allele was found (P = 0.0002). These results suggest that gene(s) within the Ig heavy chain loci may be important in the pathogenesis of IgA-GN.

Genes, Regulator↗
PubMed1988

Anti-nRNP anti-nuclear antibody-secreting cells are represented in the B-lymphocyte repertoire of normal and MRL/MP-lpr/lpr lupus mice.

Spleen cells from MRL-lpr/lpr, CBA and BALB/c mice were cultured in vitro and assayed for production of anti-nuclear antibodies. Spleen cells from all species produced IgM antibodies to a nRNP (U1-RNP)-specific antigen and to double-stranded DNA (dsDNA) after stimulation with LPS. The specificity of the anti-nRNP antibodies was shown, by immunoblotting, to be directed against the 33,000 MW polypeptide of nRNP/Sm. CBA mice produced more IgM autoantibody in vitro than MRL/lpr or BALB/c mice. In contrast, IgG anti-nRNP and anti-dsDNA antibody were not produced by any of the strains. Our data show that anti-nRNP and anti-dsDNA precursor B cells are part of the normal murine immune repertoire and are not confined to the MRL/lpr strain. This suggests that the spontaneous development of anti-nRNP and anti-dsDNA antibodies associated with systemic lupus erythematosis (SLE) is dependent on clonal stimulation and removal of suppressive influences.

Animals↗
PubMed1987

Infection of white-tailed deer (Odocoileus virginianus) in Michigan with Jamestown Canyon virus (California serogroup) and the importance of maternal antibody in viral maintenance.

Sera collected from a captive population of white-tailed deer (Odocoileus virginianus) penned in the lower peninsula of Michigan were assayed over a 29-mo period for neutralizing antibody to California serogroup viruses. In all, 130 individual white-tailed deer were bled one to 22 times between June 1983 and November 1985. Of the 130 sampled after active transmission had ceased, or passage of maternal antibody in colostrum had occurred, only one (0.8%), a newborn fawn, had no serum neutralizing antibody to California group viruses. All 18 1-yr-old does sampled acquired specific neutralizing antibody to Jamestown Canyon (JC) virus within a 6-wk period in 1984 and within a 10-wk period in 1985 indicating the prevalence of infection in this nonimmune age group was 100% for 2 successive yr. All 32 2- to 7-yr-old adult does and eight bucks sampled between June 1983 and June 1985 had specific neutralizing antibody to JC virus. No white-tailed deer had specific neutralizing antibody to trivittatus or La Crosse/snowshoe hare viruses at this study site. In 1984 and 1985, 78% and 63% of the adult does respectively exhibited significant anamnestic responses; all 19 adult does sampled over two seasons (between October 1983 and June 1985) showed a significant anamnestic response during at least 1 of the 2 yr. One-third of adult does with significant springtime antibody titer increases apparently experienced reexposure prior to the emergence of aedine mosquitoes, suggesting an alternate vector may overwinter at this site and transmit viruses in early spring. Specific neutralizing antibody was detected in 98% (66/67) of nursing fawns bled within 5 wk of birth in May-June 1984 and 1985, including three of three nursing fawns bled within 24-96 hr of birth. Of the 66 newborn fawns with specific neutralizing antibody to JC virus in June 1984 and 1985, 95% (54/57) of the surviving fawns lost maternal antibody and had no measurable titer when sampled 20-24 wk after birth, however. Serum antibody titers in 25 newborn (1984-cohort) fawns and their mothers and titers in 38 newborn (1985-cohort) fawns and their mothers were significantly correlated at the 5% and 1% levels respectively, suggesting that maternal antibody rather than a naturally acquired infection was the source of immunity in these suckling fawns.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1987

Histopathological changes in cyclosporin-treated renal allografts biopsied at one and twelve months.

Forty-four renal allograft recipients were biopsied routinely one month and one year after transplantation. All patients received cyclosporin and prednisolone. Fifteen patients had at least one rejection episode, while 29 patients never underwent rejection. At one year there were no specific histological features that enabled these two groups to be distinguished. Between one month and one year, interstitial cellular infiltrate and vascular pathology regressed, and renal function steadily improved. Interstitial fibrosis, however, was either unchanged or mildly increased in all patients. There was no correlation between the amount of interstitial fibrosis at one year and either the total dose of cyclosporin or the mean concentration during the first 3 months. Our results suggest that trough, whole blood cyclosporin concentrations, at the upper level of the therapeutic range (800-200 ng/ml), may be safely tolerated during the first 3 months, with little evidence of chronic damage at one year. At one year maintenance doses of cyclosporin can be achieved that are associated with almost normal plasma creatinine concentrations and minimal tubular atrophy and interstitial fibrosis. We expect that such doses may be continued indefinitely.

Adolescent↗
PubMed1987

Differential induction of lupus associated antinuclear antibodies in MRL mice by monoclonal anti-Sm antibodies.

The effect of monoclonal autoantibodies on immunoregulation was investigated in MRL/MpJ-lpr/lpr mice. Passive transfer of KSm2 (a monoclonal IgG2a antibody directed against the 16 kD polypeptide of Sm) induced IgG antibodies to the other major immunoreactive polypeptides of Sm (28 and 29 kD) in all mice studied, and to polypeptides of the closely related antigen nRNP/Sm in 63% of the mice. In addition an increment in IgG anti-dsDNA antibodies, and in IgA and IgM anti-Sm antibodies, over control levels was observed. These effects were not due to polyclonal activation since anti-histone antibody levels were unaffected. Two other IgG2a monoclonal antibodies: KSm5 (directed against the 28 and 29 kD Sm polypeptides) and OX 12 (directed against an irrelevant antigen) failed to modulate the autoimmune responses of the mice in any way. These results demonstrate specific antibody-mediated connectivity between B cell clones producing autoantibodies against three distinct antigens.

Animals↗
PubMed1986

Antibodies to La, Jo-1, nRNP and Sm detected by multi-track immunoblotting using a novel filter holder: a comparative study with counterimmunoelectrophoresis and immunodiffusion using sera from patients with systemic lupus erythematosus and Sjögren's syndrome.

The use of Western blotting or immunoblotting to detect autoantibodies in the serum of patients with autoimmune connective tissue diseases was investigated. An apparatus suitable for simultaneously screening 16 sera on immunoblots was used to show that a complex pattern of antibody binding polypeptides was present in whole HeLa cells. A simpler and readily interpreted pattern of binding was achieved using affinity-purified rabbit thymus antigens. Seventy-seven patients with systemic lupus erythematosus, 44 with primary Sjögren's syndrome and 50 normals were screened for anti-Sm, anti-La, anti-nRNP and anti-Jo-1 by immunoblotting and the results compared with those obtained by counterimmunoelectrophoresis and immunodiffusion. It was shown that both IgG and IgM antibodies must be analysed on immunoblots to detect the maximum number of positive sera, and that the immunoblot detects many anti-La sera which do not form precipitins.

Antibody Specificity↗
PubMed1986

Clinical and immunological evolution of oligoanuric anti-GBM nephritis treated by haemodialysis.

Eight patients with oligoanuric anti-glomerular-basement-membrane (GBM), antibody-mediated glomerulonephritis without lung haemorrhage who were not treated with plasma exchange therapy were reviewed. All had severe crescentic nephritis and required dialysis. Circulating anti-GBM antibodies disappeared gradually and spontaneously in all patients. The autoantibodies became undetectable in five patients after an average of 11 months. No patient recovered renal function. Two patients have been successfully transplanted and anti-GBM nephritis has not recurred. One of these needed a pre-transplant course of plasma exchange and immunosuppression to reduce a slightly raised anti-GBM antibody titre. Of five patients who remain on dialysis, only two cannot be transplanted due to the persistence of circulating autoantibodies. One patient died from causes unrelated to renal disease. Oligoanuric patients with anti-GBM nephritis who need dialysis rarely benefit from aggressive therapy unless lung haemorrhage is present.

Acute Disease↗
PubMed1986

Antibody class differences are detected in anti-nRNP and anti-Sm antibodies directed against distinct antigen subunits.

Antibodies to nRNP, Sm and La were detected and characterised by immunoblot analysis. A comparison was made between IgG and IgM autoantibodies in 77 patients with systemic lupus erythematosus (SLE) and 50 normal subjects. No antibodies were detected in the normal subjects. In all 3 antigen specificity groups, a heterogeneity of antibody class was observed between patients. Antibodies to the 2 nRNP-specific polypeptides (33 and 67 kD) were approximately equally frequent. Although IgG antibodies to the 67 kD polypeptide were detected in 88% of patients with antibodies to this polypeptide, IgG antibodies to the 33 kD polypeptide were only detected in 43% of patients with antibodies to this polypeptide. This suggested either that anti-33 kD antibody is produced by a B cell which cannot mature to an IgG-secretor, or that anti-33 kD antibody production succeeds an initial immune response producing anti-67 kD. Reactivity with the 29 kD, Sm-specific polypeptide appeared to be the most frequent in anti-Sm sera compared with the 16 kD polypeptide suggesting that this polypeptide may be the primary immunogenic component of Sm.

Antibodies, Antinuclear↗
PubMed1986

Adult-onset minimal change nephrotic syndrome: a long-term follow-up.

A series of 89 adult-onset nephrotic patients with minimal changes on renal biopsy was analyzed to compare the rate of response to corticosteroids and cytotoxic agents and the stability of remission or frequency of relapses at different ages. Severe hypertension and diminished renal function were more common in patients aged over 60 years, who formed 22.5% of the group. Seventy-five patients were given a first course of prednisolone in an initial dose of 60 mg/24 hr. After an eight week course of tapering doses of corticosteroids, only 45 of the 75 patients were in complete remission, 55 patients after 16 weeks and eventually 58 lost their proteinuria. The respective estimates of remission were 60%, 76% and 81%. Subsequently, of the 58 treated patients who responded, 24% never relapsed. Fifty-six percent of the patients relapsed on a single occasion or infrequently, and only 21% were frequent relapsers. Cyclophosphamide was used in 36 patients, in two as initial treatment, in 11 because of corticosteroid resistance, and in the remainder because of relapses. The time-course of loss of proteinuria was similar to that following treatment with corticosteroids, 25 (69%) losing proteinuria within 16 weeks. Only four patients failed to lose their nephrotic syndrome. Two of them had presented in acute renal failure and all four were over 60 years of age. The stability of remission after cyclophosphamide was better than that reported for children, only 13 of 36 showing relapses and 66% being in remission at five years, after which no further relapses were seen.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Cortex Hormones↗