Summary
Background
Although there are many reports of sporadic patients with paraneoplastic pemphigus (PNP), only a few systematic studies on large cohorts of patients with PNP have been reported.
...Objectives
To analyse the clinical and immunological findings in a large cohort of patients with PNP.
Methods
This retrospective study consisted of 104 patients with PNP. Clinical and histopathological manifestations, associated neoplasms, complicating diseases, prognosis and results of immunofluorescence, immunoblotting and enzyme‐linked immunosorbent assays (ELISAs) were analysed.
Results
The clinical and histopathological findings in this study were generally similar to those in previous reports. The most common associated neoplasms included malignant lymphomas, malignant solid tumours and Castleman disease, in that order, while 12 patients had no detectable tumours. Novel ELISAs for desmocollins (Dscs) showed that 19 (18·6%), 42 (41·2%) and 62 (60·8%) of 102 patients with PNP showed antibodies to Dsc1, Dsc2 and Dsc3, respectively. Thirty‐two (60%) of 53 patients had antibodies to alpha‐2‐macroglobulin‐like protein 1 (A2ML1). We found statistically significant correlations between positive desmoglein 3 reactivity and genital lesions, and between positive desmoglein 3 reactivity and bronchiolitis obliterans.
Conclusions
We consider that antibodies to Dscs and A2ML1 are useful for the diagnosis of PNP.
What's already known about this topic?
Paraneoplastic pemphigus (PNP) is an autoimmune bullous disease with polymorphous mucocutaneous lesions associated with either benign or malignant neoplasms.
Bronchiolitis obliterans with progressive respiratory failure is a cause of death in PNP.
What does this study add?
Several patients with PNP with typical clinical and immunological features did not show detectable neoplasms.
Antidesmocollin autoantibodies and antialpha‐2‐macroglobulin‐like protein 1 antibodies are useful for the diagnosis of PNP.
Linked Comment: Sprecher, Br J Dermatol 2015; 173: 1363–64.
Summary
Background
Despite the established pathogenic role of anti‐desmoglein (Dsg) antibodies in classical pemphigus, the significance of autoantibodies to another desmosomal cadherin, desmocollin ...(Dsc) is at present unknown. No consistent immunoassay for immunoglobulin (Ig) G autoantibodies to Dscs has been developed.
Objectives
The aim of this study was to develop reliable assays to detect anti‐Dsc autoantibodies.
Methods
We expressed soluble recombinant proteins (RPs) of human Dsc1–3 in mammalian cells and examined sera of various types of pemphigus, including 79 paraneoplastic pemphigus (PNP) sera, by novel enzyme‐linked immunosorbent assays (ELISAs) using the RPs. We also performed ELISAs of Dsc baculoproteins and used the complementary DNA (cDNA) transfection method, and compared the results with those of mammalian ELISAs.
Results
Through mammalian ELISAs, IgG autoantibodies to Dsc1, Dsc2 and Dsc3 were detected in 16·5%, 36·7% and 59·5% of PNP sera, respectively, and considerable numbers of pemphigus herpetiformis (PH) and pemphigus vegetans (PVeg) sera reacted strongly with Dsc1 and Dsc3. Mammalian ELISAs were highly specific and more sensitive than baculoprotein ELISAs or the cDNA transfection method. Several Dsc‐positive sera, particularly PH sera, showed no reactivity with Dsgs. The reactivity of PNP serum and PVeg serum with Dscs was not abolished by pre‐absorption with Dsg RPs.
Conclusions
The results of these novel ELISAs indicated that IgG anti‐Dsc autoantibodies were frequently detected and potentially pathogenic in nonclassical pemphigus.
What's already known about this topic?
Despite the established pathogenic role of anti‐desmoglein (Dsg) antibodies in classical pemphigus, the significance of autoantibodies to another desmosomal cadherin, desmocollin (Dsc), is at present unknown.
No consistent immunoassay for IgG autoantibodies to Dscs has been developed.
What does this study add?
We have successfully established new sensitive and specific mammalian Dsc immunoglobulin (Ig) G enzyme‐linked immunosorbent assays.
Our data show that IgG anti‐Dsc autoantibodies are frequently detected and potentially pathogenic in particular types of nonclassical pemphigus.
1-Aminocyclopropane-1-carboxylate synthase (ACS) catalyzes the rate-limiting step in the ethylene biosynthetic pathway in plants. The Arabidopsis genome encodes nine ACS polypeptides that form eight ...functional (ACS2, ACS4-9, and ACS11) homodimers and one nonfunctional (ACS1) homodimer. Transgenic Arabidopsis lines were constructed expressing the beta-glucuronidase (GUS) and green fluorescence protein (GFP) reporter genes from the promoter of each of the gene family members to determine their patterns of expression during plant development. All genes, except ACS9, are expressed in 5-d-old etiolated or light-grown seedlings yielding distinct patterns of GUS staining. ACS9 expression is detected later in development. Unique and overlapping expression patterns were detected for all the family members in various organs of adult plants. ACS11 is uniquely expressed in the trichomes of sepals and ACS1 in the replum. Overlapping expression was observed in hypocotyl, roots, various parts of the flower (sepals, pedicle, style, etc.) and in the stigmatic and abscission zones of the silique. Exogenous indole-3-acetic acid (IAA) enhances the constitutive expression of ACS2, 4, 5, 6, 7, 8, and 11 in the root. Wounding of hypocotyl tissue inhibits the constitutive expression of ACS1 and ACS5 and induces the expression of ACS2, 4, 6, 7, 8, and 11. Inducers of ethylene production such as cold, heat, anaerobiosis, and Li(+) ions enhance or suppress the expression of various members of the gene family in the root of light-grown seedlings. Examination of GUS expression in transverse sections of cotyledons reveals that all ACS genes, except ACS9, are expressed in the epidermis cell layer, guard cells, and vascular tissue. Similar analysis with root tip tissue treated with IAA reveals unique and overlapping expression patterns in the various cell types of the lateral root cap, cell division, and cell expansion zones. IAA inducibility is gene-specific and cell type-dependent across the root tip zone. This limited comparative exploration of ACS gene family expression reveals constitutive spatial and temporal expression patterns of all gene family members throughout the growth period examined. The unique and overlapping gene activity pattern detected reveals a combinatorial code of spatio-temporal coexpression among the various gene family members during plant development. This raises the prospect that functional ACS heterodimers may be formed in planta.
The pyridoxal phosphate-dependent enzyme, 1-aminocyclopropane-1-carboxylate synthase (ACS; EC 4.4.1.14), catalyzes the rate-limiting step in the ethylene biosynthetic pathway in plants. The ...Arabidopsis genome encodes nine ACS polypeptides that form eight functional (ACS2, ACS4-9, ACS11) and one nonfunctional (ACS1) homodimers. Because the enzyme is a homodimer with shared active sites, the question arises whether the various polypeptides can form functional heterodimers. Intermolecular complementation experiments in Escherichia coli by coexpressing the K278A and Y92A mutants of different polypeptides show that all of them have the capacity to heterodimerize. However, functional heterodimers are formed only among gene family members that belong to one or the other of the two phylogenetic branches. ACS7 is an exception to this rule, which forms functional heterodimers with some members of both branches when it provides the wt K278 residue. ACS1, the nonfunctional polypeptide as a homodimer, can also form functional heterodimers with members of its phylogenetic branch when its partners provide the wt K278 residue. The ACS gene family products can potentially form 45 homo- and heterodimers of which 25 are functional. Bimolecular fluorescence complementation and biochemical coaffinity purification assays show that the inactivity of certain heterodimers is not due to the absence of heterodimerization but rather to structural restraint(s) that prevents the shared active sites from being functional. We propose that functional heterodimerization enhances the isozyme diversity of the ACS gene family and provides physiological versatility by being able to operate in a broad gradient of S-adenosylmethionine concentration in various cells/tissues during plant growth and development. Nonfunctional heterodimerization may also play a regulatory role during the plant life cycle.
1-Amino-cyclopropane-1-carboxylate synthase (ACS, EC 4.4.1.14) is the key enzyme in the ethylene biosynthetic pathway in plants. The completion of the Arabidopsis genome sequence revealed the ...presence of twelve putative ACS genes, ACS1–12, dispersed among five chromosomes. ACS1–5 have been previously characterized. However, ACS1 is enzymatically inactive whereas ACS3 is a pseudogene. Complementation analysis with the Escherichia coli aminotransferase mutant DL39 shows that ACS10 and 12 encode aminotransferases. The remaining eight genes are authentic ACS genes and together with ACS1 constitute the Arabidopsis ACS gene family. All genes, except ACS3, are transcriptionally active and differentially expressed during Arabidopsis growth and development. IAA induces all ACS genes, except ACS7 and ACS9; CHX enhances the expression of all functional ACS genes. The ACS genes were expressed in E. coli, purified to homogeneity by affinity chromatography, and biochemically characterized. The quality of the recombinant proteins was verified by N-terminal amino acid sequence and MALDI-TOF mass spectrometry. The analysis shows that all ACS isozymes function as dimers and have an optimum pH, ranging between 7.3 and 8.2. Their Km values for AdoMet range from 8.3 to 45 μm, whereas their kcat values vary from 0.19 to 4.82 s–1 per monomer. Their Ki values for AVG and sinefungin vary from 0.019 to 0.80 μm and 0.15 to 12 μm, respectively. The results indicate that the Arabidopsis ACS isozymes are biochemically distinct. It is proposed that biochemically diverse ACS isozymes function in unique cellular environments for the biosynthesis of C2H4, permitting the signaling molecule to exert its unique effects in a tissue- or cell-specific fashion.
To investigate the incidence of deepening of upper eyelid sulcus (DUES) with topical use of tafluprost in Japanese glaucoma patients.
This study was a prospective, open-label, non-controlled case ...series conducted at a single center. Thirty-six primary open-angle glaucoma Japanese patients who had no history of surgery were enrolled. The patients were prescribed 0.0015% topical tafluprost once daily to one eye that had the more severe visual field disorder, and observed during outpatient visits before and at 30, 60, and 90 days after starting treatment. At every visit, three examiners judged the presence of DUES unanimously by facial photographs including eyebrows and lower eyelids. The primary outcome variable was the incidence of DUES at the end of day 90 in the study as assessed by observer-masked facial photography. The patients were also asked if they noticed any subjective symptom of DUES. Gender, refraction, and intraocular pressure were evaluated as potential risk factors.
Thirty-two patients completed this clinical trial. DUES were identified objectively in 19% (6/32) of the patients after 90 days of treatment. The incidence was not related to gender, refraction, baseline or post-treatment intraocular pressure, or intraocular pressure reduction. Finally, 17% (1/6) of patients with objectively diagnosed DUES noticed the presence of DUES by themselves. No patient dropped out of the study because of DUES.
Similar to other prostaglandin analogs, topical use of tafluprost ophthalmic solution is associated with DUES as a local adverse reaction.
We report a 68-year-old Japanese female patient with subepidermal blistering disease with autoantibodies to multiple laminins, who subsequently developed membranous glomerulonephropathy. At skin ...disease stage, immunofluorescence demonstrated IgG anti-basement membrane zone antibodies reactive with dermal side of NaCl-split skin. Immunoblotting of human dermal extract, purified laminin-332, hemidesmosome-rich fraction and laminin-521 trimer recombinant protein (RP) detected laminin γ-1 and α-3 and γ-2 subunits of laminin-332. Three years after skin lesions disappeared, nephrotic symptoms developed. Antibodies to α-3 chain of type IV collagen (COL4A3) were negative, thus excluding the diagnosis of Goodpasture syndrome. All anti-laminin antibodies disappeared. Additional IB and ELISA studies of RPs of various COL4 chains revealed reactivity with COL4A5, but not with COL4A6 or COL4A3. Although diagnosis of anti-laminin γ-1 (p200) pemphigoid or anti-laminin-332-type mucous membrane pemphigoid could not be made, this case was similar to previous cases with autoantibodies to COL4A5 and/or COL4A6.
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