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K E Harman

Publications and source records attributed to K E Harman.

16 recordsLinked to original sources
PubMed2002

New laboratory techniques for the assessment of acquired immunobullous disorders.

This review aims to summarize investigations that are used in the assessment of patients with suspected immunobullous disorders. Emphasis is placed upon new adaptations of existing techniques and the advent of recombinant technology, which has enabled the production of synthetic antigens. The use of recombinant antigens has provided the latest generation of diagnostic techniques that are likely to make a major impact on routine diagnosis of immunobullous disorders.

Autoantigens↗
PubMed2001

The severity of cutaneous and oral pemphigus is related to desmoglein 1 and 3 antibody levels.

BACKGROUND: Pemphigus vulgaris (PV) and foliaceus (PF) are characterized by antibodies to the desmosomal proteins desmoglein 3 (Dsg3) and desmoglein 1 (Dsg1), respectively. Past studies using indirect immunofluorescence (IIF) as a measure of pemphigus antibody levels have failed to demonstrate consistently a relationship between disease severity and IIF titres. However, IIF is not able to measure separately Dsg1 and 3 antibodies, unlike enzyme-linked immunosorbent assays (ELISA), which utilize recombinant proteins. OBJECTIVES: To compare independently Dsg1 and 3 antibody levels with the severity of both cutaneous and oral involvement in PV and PF. Patients and methods Four hundred and twenty-four serum samples were analysed from 80 subjects with PV and 24 with PF. IgG antibodies to Dsg1 and 3 were measured by ELISA. For every sample analysed, the associated severity of skin and oral disease were graded from 0 to 3; quiescent, mild, moderate and severe. RESULTS: A relationship between Dsg1 antibodies and skin severity was demonstrated such that a 10-unit increase in Dsg1 ELISA value was associated with a 34% chance of having a higher severity score [95% confidence interval (CI), 25-45%, P < 0.0005]. This was observed in both PV and PF. Oral severity was associated with Dsg3 antibody levels and a 10-unit increase in the Dsg3 ELISA value was associated with a 25% chance of a higher oral severity score (CI 17-33%, P < 0.0005). We were unable to demonstrate a relationship between Dsg1 antibodies and oral severity, even after adjusting for the effect of Dsg3 antibodies. Similarly, there was no relationship between Dsg3 antibodies and skin severity. CONCLUSIONS: This study suggests that the clinical phenotype of pemphigus, in particular the balance of skin and oral disease, is determined principally by the quantities of Dsg1 and 3 autoantibodies, respectively.

Autoantibodies↗
PubMed2000

The use of two substrates to improve the sensitivity of indirect immunofluorescence in the diagnosis of pemphigus.

The aim of this study was to re-evaluate indirect immunofluorescence (IIF) comparing two substrates, normal human skin (HS) and monkey oesophagus (MO) using serum from 29 pemphigus patients classified according to the presence of serum autoantibodies to either desmoglein (Dsg) 1 or Dsg3 detected by enzyme-linked immunosorbent assay (ELISA). Overall, the sensitivity of IIF was 83% on HS and 90% on MO. When data from both substrates were combined, the sensitivity increased to 100%. When sera from pemphigus foliaceus (PF) patients were studied, which contained Dsg1 antibodies only, the sensitivity of IIF was greatest on HS and titres were on average 4.8 doubling dilutions higher than on MO. In contrast, when sera containing autoantibodies only to Dsg3 from pemphigus vulgaris (PV) patients was studied, the sensitivity was greatest on MO and titres were on average 4.4 doubling dilutions higher than on HS. There was a significant correlation between Dsg1 antibody levels and IIF titres on HS and between Dsg3 antibody levels and IIF titres on MO. The investigation of immunobullous disorders in the future is likely to move towards antigen-specific techniques such as the Dsg ELISAs used in this study. However, in laboratories which currently rely on IIF for detecting pemphigus autoantibodies, the data presented in this study strongly suggest that two substrates should be used for IIF screening: one rich in Dsg1, such as HS, and the other rich in Dsg3, such as MO. This combination of substrates should not only increase the sensitivity of detecting pemphigus antibodies, but will aid in the differentiation of PV from PF. It is also possible that the data might be more useful for disease monitoring.

Animals↗
PubMed2000

A study of desmoglein 1 autoantibodies in pemphigus vulgaris: racial differences in frequency and the association with a more severe phenotype.

BACKGROUND: Pemphigus vulgaris (PV) is characterized by pathogenic autoantibodies to desmoglein (Dsg) 3, but additional antibodies to Dsg1, the pemphigus foliaceus antigen, are detectable in some cases. OBJECTIVES: To investigate the clinical significance of the presence of both Dsg 1 and 3 antibodies. METHODS: In 79 subjects with PV, enzyme-linked immunosorbent assays were used to detect IgG autoantibodies reactive with the ectodomain of Dsg1 and Dsg3. RESULTS: There was a clear association between the clinical phenotype and the Dsg antibody profile. All subjects had Dsg3 autoantibodies and 61% had coexisting Dsg1 antibodies (Dsg3+/Dsg1+). PV limited entirely to the mucosal surfaces was seen only in Dsg3+/Dsg1- patients, while additional Dsg1 antibodies (Dsg3+/Dsg1+) predicted cutaneous in addition to mucosal involvement. Although minor cutaneous involvement was observed in most Dsg3+/Dsg1- patients, severe cutaneous involvement was seen only in Dsg3+/Dsg1+ patients. Dsg1 antibodies were detectable early in the course of disease and their appearance did not relate to the use of systemic therapy. The proportion of Dsg1+ patients was higher in those of Indian origin compared with white northern Europeans (P < 0.05). CONCLUSIONS: These data suggest that the presence of Dsg1 antibodies is predictive of a potentially more severe disease and that genetic factors may determine the Dsg antibody profile.

Autoantibodies↗
PubMed2000

Diagnosis of pemphigus by ELISA: a critical evaluation of two ELISAs for the detection of antibodies to the major pemphigus antigens, desmoglein 1 and 3.

Pemphigus vulgaris (PV) and pemphigus foliaceus (PF) are characterized by autoantibodies to the desmosomal glycoproteins desmoglein 3 (Dsg 3) and Dsg 1 (Dsg 1), respectively. In this study, two enzyme-linked immunosorbent assays (ELISA) which detect IgG autoantibodies to Dsg 1 and Dsg 3 have been evaluated. A total of 317 normal and disease controls, 82 patients with PV and 25 with PF were studied. The Dsg 3 ELISA was positive in all 34 patients with untreated PV and the Dsg 1 ELISA was positive in all 10 with untreated PF. When patients undergoing treatment were included, the sensitivities fell to 95% and 92%, respectively, but still compared favourably to the sensitivity of indirect immunofluorescence which was 79% in PV and 84% in PF. All PF sera were negative in the Dsg 3 ELISA and the specificity of both assays was 98% or greater. Large numbers of samples could be analysed simultaneously over a relatively short time period. The Dsg 1 and Dsg 3 ELISAs also provided objective, quantitative, reproducible data which allowed differentiation of PV from PF and in view of these advantages, they are likely to become a routine technique in diagnostic laboratories.

Adolescent↗
PubMed1999

Molecular mapping of the major epitopes of BP180 recognized by herpes gestationis autoantibodies.

Herpes gestationis (HG) is an autoantibody-mediated subepidermal bullous dermatosis associated with pregnancy. The primary target of HG autoantibodies is BP180, a 180-kDa hemidesmosomal glycoprotein. We previously showed that autoantibodies and autoimmune T lymphocytes from HG patients recognize the MCW-1 antigenic site (AA 507-520), which is located in the membrane-proximal noncollagenous domain (NC16A) of BP180. Here, we analyzed the sera of 37 HG patients to further define the sites on BP180 that are targeted by autoantibodies. All of the HG sera, but none of the control sera, were immunoreactive with sec180e, a 120-kDa recombinant protein encompassing the entire BP180 extracellular domain. HG sera depleted of reactivity to NC16A no longer reacted with sec180e, indicating that the major HG-associated epitopes on BP180 are restricted to the NC16A domain. The vast majority of the HG sera (34 of 37) reacted with a 7 amino acid peptide corresponding to the N-terminal half of MCW-1 (MCW-1A). Eleven HG sera (including the 3 that failed to react with MCW-1A) recognized one or more of three antigenic sites located within a 15 amino acid stretch immediately downstream of MCW-1A. In summary, we have identified four major HG-associated epitopes clustered within a 22 amino acid region of the BP180 ectodomain. These findings support the hypothesis that an autoimmune response to the BP180 NC16A domain is a crucial step in the pathogenesis of HG.

Antibody Specificity↗
PubMed1999

High-dose intravenous immune globulin for the treatment of autoimmune blistering diseases: an evaluation of its use in 14 cases.

High-dose intravenous immune globulin (IVIG) is used to treat a wide variety of autoimmune diseases. We report our experiences of its use in a retrospective study of 14 patients with autoimmune blistering diseases, namely epidermolysis bullosa acquisita (EBA), two; bullous pemphigoid (BP), two; pemphigoid gestationis (PG), one; nodular pemphigoid, two; and pemphigus vulgaris (PV), seven. Two patients with refractory EBA improved following regular courses of IVIG given as monotherapy. IVIG had a steroid-sparing effect in 10 patients with PV, BP and PG. However, the clinical effects were transient and of variable intervals, and repeated courses of IVIG were required. The rapid actions of IVIG were of particular benefit in two patients with extensive, rapidly progressive PV and in one patient with BP in whom swift disease control was required. In such cases, when rapid disease control is paramount, we recommend IVIG used in conjunction with conventional treatments as a safer and less invasive alternative to plasmapheresis. IVIG was ineffective in two patients with nodular pemphigoid. Analysis of indirect immunofluorescence (IIF) titres before and after IVIG showed that a fall in titre occurred after 78% of treatments and was observed in all disease groups. However, like the clinical improvements, the falls in IIF titres were transient and of variable interval, and titres rose back to pretreatment levels in all but one patient. IVIG appears to be beneficial under certain circumstances for the treatment of autoimmune blistering diseases but controlled trials are required to define its therapeutic role further.

Adolescent↗
PubMed1999

Defining target antigens in linear IgA disease using skin from subjects with inherited epidermolysis bullosa as a substrate for indirect immunofluorescence microscopy.

Identification of target antigens in immunobullous disorders usually involves laborious techniques such as immunoblotting and immunoprecipitation, which do not always provide conclusive data. This is particularly true of linear IgA disease (LAD) in which the target antigen has often proved difficult to identify. As an alternative means of antigen identification in five adult patients with LAD, we performed indirect immunofluorescence (IIF) microscopy on a panel of skin samples taken from subjects with different forms of inherited epidermolysis bullosa (EB). Skin samples were selected that showed a complete absence of immunostaining for a specific basement membrane zone (BMZ) molecule (type VII collagen, laminin 5 or the 180-kDa bullous pemphigoid antigen BP180). In each case, the underlying genetic mutations had been defined and shown to consist of premature termination codons on both alleles of the particular gene, resulting in total ablation of the encoded protein. Two epidermal-binding LAD sera showed BMZ fluorescence on all substrates except BP180-deficient skin, suggesting that the target antigen was BP180, or a closely related molecule. In contrast, two dermal-binding LAD sera were positive on all substrates except the type VII collagen-deficient skin, suggesting that the target antigen was likely to be type VII collagen. One LAD serum sample, which showed combined dermal and epidermal fluorescence on normal salt-split skin, was also positive on all substrates tested, suggesting a target antigen other than type VII collagen, laminin 5 or BP180. The study confirms that LAD is a heterogeneous disorder and illustrates that IIF using a panel of skin samples which lack specific BMZ molecules, taken from subjects with inherited EB, is a relatively simple and useful tool to help identify target antigens in immunobullous disorders.

Adult↗
PubMed1999

Intercellular IgA dermatosis (IgA pemphigus)--two cases illustrating the clinical heterogeneity of this disorder.

IgA pemphigus is rare but may be underdiagnosed. We describe two cases, a 50-year-old female with a pustular eruption resembling subcorneal pustular dermatosis and a 55-year-old male with a pruritic vesiculopustular eruption simulating dermatitis herpetiformis. They illustrate the clinical heterogeneity of IgA pemphigus which is likely to reflect differences in autoantigens, analogous to pemphigus vulgaris and pemphigus foliaceus. There is now evidence that IgA pemphigus encompasses at least two subgroups: a subcorneal pustular dermatosis (SPD)-type, (see case 1) characterized by subcorneal pustules and autoantibodies to desmocollin 1; and intra-epidermal neutrophilic dermatosis (IEN)-type cases (see case 2) which show intra-epidermal pustules and in whom the autoantigen may be desmoglein 3, the pemphigus vulgaris antigen.

Anti-Inflammatory Agents↗
PubMed1999

Allelic heterogeneity of dominant and recessive COL7A1 mutations underlying epidermolysis bullosa pruriginosa.

The inherited mechanobullous disease, dystrophic epidermolysis bullosa, is caused by type VII collagen gene (COL7A1) mutations. We studied six unrelated patients with a distinct clinical subtype of this disease, epidermolysis bullosa pruriginosa, characterized by pruritus, excoriated prurigo nodules, and skin fragility. Mutation analysis using polymerase chain reaction amplification of genomic DNA, heteroduplex analysis and direct nucleotide sequencing demonstrated pathogenetic COL7A1 mutations in each case. Four patients had a glycine substitution mutation on one COL7A1 allele (G1791E, G2242R, G2369S, and G2713R), a fifth was a compound heterozygote for a splice site mutation (5532 + 1G-to-A) and a single base pair deletion (7786delG), and a sixth patient was heterozygous for an out-of-frame deletion mutation (6863del16). This study shows that the molecular pathology in patients with the distinctive clinical features of epidermolysis bullosa pruriginosa is heterogeneous and suggests that other factors, in addition to the inherent COL7A1 mutation(s), may be responsible for an epidermolysis bullosa pruriginosa phenotype.

Adolescent↗
PubMed1998

Scleromyxoedema and thrombotic thrombocytopaenic purpura: two rare conditions both responding to plasma exchange.

We report the case of a 66-year-old female who over an 18-month period developed severe, disabling scleromyxoedema with pulmonary fibrosis. Treatment with oral prednisolone and melphalan had failed to prevent disease progression. Treatment with a 5-day course of plasma exchange, intravenous cyclophosphamide (500 mg) and methyl-prednisolone (1 g on 3 consecutive days) was unfortunately followed by the development of thrombotic thrombocytopaenic purpura (TTP). After 17 extra plasma exchanges, she recovered and there has been a dramatic improvement in her skin signs. We postulate that the extra plasma exchanges which she received as a consequence of developing TTP have contributed to this result. To our knowledge, TTP has never been associated with scleromyxoedema, but it is likely to be a coincidence in this case.

Aged↗