Biomedical subjects

M Gallicchio

Publications and source records attributed to M Gallicchio.

23 records · Page 2Linked to original sources

PubMed1991

Autoantibodies in systemic vasculitis.

We have studied 495 sera that were referred to us from patients suspected on clinical and/or histological grounds to have a small vessel vasculitis. These sera were tested for antibodies against neutrophil cytoplasm antigens (anti-neutrophil cytoplasm antibodies, ANCA) using assays based on neutrophil acid extract, myeloperoxidase and elastase. Such antibodies are commonly found in Wegener's granulomatosis (WG) and microscopic polyarteritis (MPA), and sometimes in other small vessel vasculitides. One hundred and twenty-six of these sera (25%) were positive in the acid extract ELISA, 68 (14%) in the assay for anti-myeloperoxidase antibodies and 35 (16%) in the assay for anti-elastase antibodies. A total of 166 sera (34%) were positive for antibodies against neutrophil cytoplasm constituents. No ANCA, anti-myeloperoxidase or anti-elastase antibodies were detected in 26 convalescent sera from patients either with WG or MPA, or who had previously been positive. The mean time between positive and negative sera was eight weeks (range three weeks to six months) and three out of three who relapsed again developed ANCA of the same specificity as the original sera. Of the 228 sera also tested for anti-GBM antibodies, 13 (5.7%) were positive. All these contained antibodies against neutrophil cytoplasm constituents (three against the acid extract, eight against myeloperoxidase and two against elastase). Forty-nine of the 74 sera (66%) tested for ANA were positive. Twenty-nine (39%) had a speckled and 20 (27%) had a homogeneous pattern.(ABSTRACT TRUNCATED AT 250 WORDS)

Antibodies, Antinuclear↗

PubMed1991

Circulating anti-glomerular basement membrane antibodies in coeliac disease and epidermolysis bullosa acquisita.

The demonstration of circulating anti-glomerular basement membrane (GBM) antibodies is almost diagnostic for anti-GBM disease and Goodpasture's syndrome. These antibodies are, however, occasionally present in SLE and diabetes, in association with IgA disease and membranous nephropathy and after transplantation in Alport's syndrome. In addition, we describe circulating anti-GBM antibodies in a research worker who handled GBM and in whom coeliec disease later developed, and in an individual with epidermolysis bullosa acquisita. Neither patient had impaired renal function nor an abnormal urinary sediment, suggesting either that these antibodies were of low affinity, or that additional factors are required for the pathogenesis of an aggressive glomerular lesion when circulating anti-GBM antibodies are present. In at least one of these individuals anti-GBM antibodies may have developed after the exposure of basement membrane collagen type IV to activated immunological mediators and cells.

Adult↗

PubMed1991

The non-collagenous domains of the alpha 3 and 4 chains of type IV collagen and their relationship to the Goodpasture antigen.

The Goodpasture antigen is the target recognized by anti-glomerular basement membrane (GBM) antibodies in anti-GBM disease or Goodpasture's syndrome. This structure is present in all normal GBM, but when serum containing anti-GBM antibodies is used to examine renal tissue from most males with classical Alport's syndrome, the Goodpasture antigen appears to be missing. The nature of the Goodpasture antigen is uncertain although it has been putatively and controversially localized to the non-collagenous domain of a novel type IV collagen chain (alpha 3) by one group, and a short peptide sequence has been published (M2). We have performed several experiments to determine whether M2 represents the Goodpasture antigen and we have also studied the corresponding sequence of the alpha 4 chain of type IV collagen (M3). Firstly, we demonstrated by polymerase chain reaction (PCR) amplification using specific priming oligonucleotides that mRNAs corresponding to M2 and M3 were found within the kidney and that the published sequences were correct. When heterologous antibodies were raised against M2 and M3 these bound specifically to GBM in an ELISA based on collagenase-digested basement membrane and this binding could be inhibited by incubation with collagenase-digested GBM but not with ovalbumin. On further examination of the target molecules using Western blots, the anti-M2 antibody bound to a single high molecular weight band of collagen-digested GBM in contrast to the anti-M3 antibody that bound to the same bands as Goodpasture serum. We then established ELISAs for anti-M2 and anti-M3 activity using the peptides M2 and M3. While rabbit anti-M2 and M3 antibodies bound specifically to their respective peptides in these ELISAs, there was no binding of three high titre Goodpasture's syndrome sera or two sera from Alport's syndrome patients with inhibitable anti-GBM antibody post-renal transplant. We have shown that the sequences of M2 and M3 correspond to proteins present within the collagenase-resistant part of the GBM, suggesting that these do represent parts of novel type IV collagen chains. However, sera containing anti-GBM antibodies did not bind to either peptide in solid-phase ELISAs, and these antibodies may recognize a different peptide sequence, features of the tertiary structure of these peptides or interactions between collagen chains.

Anti-Glomerular Basement Membrane Disease↗

PubMed1990

Diverse target antigens recognized by circulating antibodies in anti-neutrophil cytoplasm antibody-associated renal vasculitides.

Antibodies that are directed against cytoplasmic constituents of neutrophils and monocytes (anti-neutrophil cytoplasm antibodies, ANCA) have been described in Wegener's granulomatosis, microscopic polyarteritis (MPA) and some cases of segmental necrotizing glomerulonephritis (SNGN). Other antibodies occasionally described in Wegener's granulomatosis and MPA include anti-nuclear antibodies (ANA) and anti-glomerular basement membrane (GBM) antibodies. We have studied the diversity of the corresponding antigens in ANCA-associated renal diseases. Sera from 46 patients with active histologically proven Wegener's granulomatosis, MPA and SNGN were tested for ANCA by indirect immunofluorescent examination of normal peripheral blood neutrophils. Thirty-four sera (74%) were positive; 16 were associated with diffuse cytoplasmic staining (cANCA) and 18 with perinuclear staining (pANCA). In addition, five demonstrated antineutrophil-specific nuclear staining (ANNA). On Western blotting of the neutrophil extract, five sera recognized a 29-kD molecule recently identified as neutrophil proteinase 3. Two sera with typical cANCA bound to molecules of 36, 38 and 116 kD and another to a molecule of 22 kD. The final serum associated with pANCA bound to a molecule of about 12 kD. Thirteen sera out of 46 (28%) tested in an ELISA contained anti-myeloperoxidase antibodies; 10 of these were associated with pANCA and two others with ANNA. Three sera of 17 (18%) tested contained anti-elastase antibodies; these also contained anti-myeloperoxidase antibodies and were associated with pANCA. However, eight sera with pANCA were negative for anti-myeloperoxidase antibodies and three of these were also negative for anti-elastase antibodies, suggesting further unidentified target antigen or antigens associated with the pANCA. Fifteen of the 34 sera positive for ANCA also demonstrated anti-nuclear staining on Hep-2 cells (53%) in a speckled, homogeneous, or nucleolar pattern. ANA were significantly associated with the presence of pANCA (P less than 0.01), and levels of ANA and ANCA fell in parallel after treatment. One serum with a pANCA was also positive for anti-GBM antibodies. Inhibition studies using ELISAs for anti-GBM antibodies indicated that there was no cross-reactivity between target molecules recognized by these antibodies. The diversity of target molecules recognized by ANCA suggests that cross-reactivity with bacterial structures is less likely as the primary aetiological event in the development of these antibodies than tissue destruction; and that cross-reactivity with vascular endothelium is also unlikely as the pathogenetic basis of vessel disease.

Antibodies, Antinuclear↗

PubMed1989

Two ELISAs to detect anti-neutrophil cytoplasm antibodies (ANCA) in various vasculitides.

Anti-neutrophil cytoplasm antibodies (ANCA) are present in the serum of patients with Wegener's granulomatosis, microscopic polyarteritis, and some other small vessel vasculitides. There are at least 2 different anti-neutrophil cytoplasm antibodies identified by their distinctive cytoplasmic staining patterns on indirect immunofluorescence examination. The only antigen identified to date is myeloperoxidase which has a perinuclear distribution on alcohol-fixed neutrophils and monocytes. We have established an ELISA that detects all anti-neutrophil cytoplasm antibodies and one specific for anti-myeloperoxidase antibodies. In the ELISA for anti-neutrophil cytoplasm antibodies, all sera with diffuse cytoplasmic or perinuclear neutrophil staining on indirect immunofluorescence examination bound at levels greater than the normal range (34%, m + 4SD). Three convalescent sera that were negative by indirect immunofluorescence examination were also negative in the assay. Positive sera could be detected at a dilution of 2 and inhibition studies showed that the binding was specific for the neutrophil extract. However, the presence of anti-neutrophil antibodies (ANA), anti-mitochondrial antibodies or immune complexes resulted occasionally in binding in the positive range. Where positive binding was noted in non-vasculitic segmental necrotizing glomerulonephritis, the binding could not be inhibited by pre-incubation with the neutrophil extract. The ELISA for ANCA is a sensitive, objective screening technique that can be performed in parallel with the assay for anti-glomerular basement antibodies to exclude the presence of anti-neutrophil cytoplasm antibodies in patients presenting with rapidly progressive glomerulonephritis. The ELISA for anti-myeloperoxidase antibodies may identify a subset of patients with distinct clinical or prognostic features.

Cytoplasm↗