Ocular cicatricial pemphigoid (OCP) is a chronic bilateral, blinding, cicatrizing form of conjunctivitis with relapsing and remitting periods. It has strong evidence for an immune type II hypersensitivity that leads to subconjunctival fibrosis and extensive systemic bullae formation. To the best knowledge of the authors, this is the first reported case of direct immunofluorescence (DIF) assay-proven OCP in an elderly Filipino man.

A 68-year-old male presented with bilateral corneal conjunctivalization, symblepharon, ectropion, conjunctival hyperemia testing positive with conjunctival biopsy for basement membrane antibodies with DIF for the left eye, while turning out negative for the right eye. He was managed as a case of OCP, both eyes, and was given topical steroids and antibiotics. Oral Dapsone was started by Dermatology and Rheumatology Services.

OCP is a rare autoimmune and blinding disease. Early diagnosis and prompt treatment are vital as ocular complications permanently affect the quality of life of patients as seen in our patient. DIF assay remains the gold-standard for diagnosis. Systemic immunosuppression is the mainstay of treatment. Adjunctive supportive topical medication may be given to alleviate ocular discomfort. A multidisciplinary approach is essential to provide holistic care to each patient.

Pemphigus foliaceous is a rare autoimmune blistering disease, while psoriasis is a common immune‑mediated inflammatory skin disease. The coexistence of psoriasis and pemphigus foliaceous has rarely been reported. We report a case of a 55‑year‑old Filipino female with an 8‑year history of chronic plaque‑type psoriasis biopsy‑proven. After 5 years, she developed generalized flaccid bullae and crusted erosions over the face, trunk, and extremities, with no mucous membrane involvement. Skin punch biopsy, direct immunofluorescence, and enzyme‑linked immunosorbent assay were consistent with pemphigus foliaceous. The combination of topical corticosteroids and oral methotrexate was selected as the therapeutic approach, leading to a notable improvement in the patient’s condition. This case report underscores the significance of identifying the simultaneous presence of psoriasis alongside autoimmune blistering diseases like pemphigus foliaceous. Examining predisposing and triggering factors, performing re‑biopsy, and further work‑up as the disease evolves may yield more profound insights. Nonetheless, effectively managing this condition poses a significant challenge.
Fluorescent Antibody Technique, Direct ; Methotrexate ; Psoriasis

Molting is an important physiological phenomenon of many metamorphosis insects, during which the old and new epidermis are separated by enzymes present in the molting fluid. Various proteomic studies have discovered the presence of Bombyx mori carboxypeptidase A (Bm-CPA) in the molting fluid of silkworm, but its function remains unclear. In order to better understand the role of Bm-CPA in the molting process of silkworm, Bm-CPA was analyzed by bioinformatics analysis, real-time fluorescence quantitative PCR, antibody preparation, immunofluorescence staining, and expression in Pichia pastoris. The results showed that Bm-CPA had a conserved M14 zinc carboxypeptidase domain and glycosylation site. Its expression was regulated by ecdysone 20E, and large expression was observed in the epidermis of the upper cluster stage. Immunofluorescence staining showed that Bm-CPA was enriched in the epidermis during the molting stage, and the inhibitor of Bm-CPA led to the larval death due to the inability to molt. We also successfully obtained a large number of recombinant Bm-CPA proteins by Pichia pastoris expression in vitro. These results may facilitate further understanding the molting development process of silkworm.
Animals ; Molting/genetics* ; Bombyx/genetics* ; Carboxypeptidases A/metabolism* ; Proteomics ; Larva/metabolism* ; Fluorescent Antibody Technique ; Insect Proteins/metabolism*

To explore the clinical diagnostic efficacy of antineutrophil cytoplasmic antibody associated vasculitis (AAV) by comparing the consistency and coincidence rate of serum anti-myeloperoxidase (MPO) antibody and anti-protease 3 (PR3) antibody detected by digital liquid chip method (DLCM) and enzyme-linked immunosorbent assay (ELISA). To provide reference for the selection of detection methods of anti-MPO antibody and anti-PR3 antibody in clinical laboratory. This study is a cross-sectional study, a total of 307 cases of antineutrophil cytoplasmic antibodies were detected in the Department of Clinical Immunology, West China Hospital of Sichuan University from January to March 2021. The serum samples and related clinical information were collected. At the same time, the levels of anti-MPO antibody and anti-PR3 antibody in serum samples were detected by ELISA and DLCM, indirect immunofluorescence (IIF) was used to re-test the differential samples between the two methods. SPSS 26.0 was used to analyze the test results, Cohen's kappa coefficient analysis was used to compare the consistency of the two methods, and paired chi-square test was used to compare the sensitivity and specificity of the two methods to AAV. The results showed that the positive cases of anti-MPO antibody detected by ELISA and DLCM were 63 and 44, and the negative cases were 244 and 263; the positive cases of anti-PR3 antibody detected by ELISA and DLCM were 34 and 28, and the negative cases were 273 and 279. The results of anti-MPO antibody and anti-PR3 antibody detected by the two methods had good consistency and coincidence rate, in which the total coincidence rate of anti-MPO antibody was 92.51%, the positive coincidence rate was 66.67%, and the negative coincidence rate was 99.18%. The results of consistency analysis showed that kappa=0.741 had well consistency. The total coincidence rate of anti-PR3 antibody is 96.74%, the positive coincidence rate is 76.47%, and the negative coincidence rate is 99.27%. The consistency analysis results show that kappa=0.821 had strong consistency. The results of IIF re-test of differential samples showed that the coincidence rate between DLCM and IIF was higher. The results of comparative analysis of anti-MPO antibody and anti-PR3 antibody showed that the specificity of DLCM was better than that of ELISA, and its sensitivity was lower than that of ELISA. In conclusion, the results of anti-MPO antibody and anti-PR3 antibody detected by DLCM were consistent with those of ELISA. In the combined detection of anti-MPO antibody and anti-PR3 antibody, the specificity of DLCM is better than that of ELISA.
Humans ; Antibodies, Antineutrophil Cytoplasmic/analysis* ; Myeloblastin ; Cross-Sectional Studies ; Sensitivity and Specificity ; Fluorescent Antibody Technique, Indirect ; Enzyme-Linked Immunosorbent Assay/methods*

Hailey-Hailey disease (HHD) is an uncommon acantholytic disorder of the skin. This is a case of a 64-year-old Filipino female with a chronic history of painful and malodorous intertriginous plaques. Histopathologic evaluation showed overlapping features of pemphigus vulgaris and Hailey-Hailey disease. A negative direct immunofluorescence test clinched the diagnosis of Hailey-Hailey disease. The patient was advised regarding preventive measures and treated with topical antibiotics and corticosteroids with improvement of her lesions.
Pemphigus, Benign Familial ; Fluorescent Antibody Technique, Direct

Pemphigus vulgaris is an autoimmune bullous dermatosis presenting with flaccid blisters and erosions. The morphology of pemphigus reflects the more superficial intraepidermal level of split seen histologically in contrast with pemphigoid, where the level of split is deep below the epidermis. This is a case of a 58-year-old male clinically presenting with arcuate tense bullae, which are more characteristic of the pemphigoid group of disorders, which revealed an intraepidermal split and tombstoning pattern of the basal epidermis on histopathology. Direct immunofluorescence revealed intercellular IgG and C3 distribution. Although this patient presented clinically with tense bullae, the histopathology and direct immunofluorescence results were consistent with pemphigus vulgaris.
Pemphigus ; Fluorescent Antibody Technique, Direct

Different fragments of SARS-CoV-2 nucleocapsid (N) protein were expressed and purified, and a fluorescence immunochromatography method for detection of SARS-CoV-2 total antibody was established. The effect of different protein fragments on the performance of the method was evaluated. The N protein sequence was analyzed by bioinformatics technology, expressed in prokaryotic cell and purified by metal ion affinity chromatography column. Different N protein fragments were prepared for comparison. EDC reaction was used to label fluorescence microsphere on the synthesized antigen to construct sandwich fluorescence chromatography antibody detection assay, and the performance was systemically evaluated. Among the 4 prepared N protein fragments, the full-length N protein (N419) was selected as the optimized coating antigen, N412 with 0.5 mol/L NaCl was used as the optimal combination; deleting 91-120 amino acids from the N-terminal of N412 reduced non-specific signal by 87.5%. the linear range of detection was 0.312-80 U/L, the limit of detection was 0.165 U/L, and the accuracy was more than 95%. A fluorescence immunochromatographic detection method for analysis of SARS-CoV-2 total antibody was established by pairing N protein fragments. The detection result achieved 98% concordance with the commercially available Guangzhou Wanfu test strip, which is expected to be used as a supplementary approach for detection of SARS-CoV-2. The assay could also provide experimental reference for improving the performance of COVID-19 antibody detection reagents.
Antibodies, Viral ; COVID-19 ; Chromatography, Affinity ; Fluorescent Antibody Technique ; Humans ; Microspheres ; SARS-CoV-2 ; Sensitivity and Specificity

Objective: The definite diagnosis of human and animal prion diseases depends on the examination of special pathological changes and/or detection of PrP in the brain tissues of suspected cases. Thus, developing methods to obtain PrP antibody with good specificity and sensitivity is fundamental for prion identification. Methods: We prepared a PrP-specific polyclonal antibody (pAb P54) in a -knockout mouse model immunization with recombinant full-length human PrP protein residues 23-231. Thereafter, we verified that pAb in Western blot, immunohistochemistry (IHC), and immunofluorescent (IFA) assays. Results: Western blot illustrated that the newly prepared pAb P54 could react with recombinant PrP protein, normal brain PrP from healthy rodents and humans, and pathological PrP in the brains of experimental rodents infected with scrapie and humans infected with different types of prion diseases. The electrophoretic patterns of brain PrP and PrP observed after their reaction with pAb P54 were nearly identical to those produced by commercial PrP monoclonal antibodies. Three glycosylated PrP molecules in the brain homogenates were clearly demonstrated in the reactions of these molecules with pAb P54. IHC assay revealed apparent PrP deposits in the GdnCl-treated brain slices of 139A-infected mice and 263K-infected hamsters. IFA tests with pAb P54 also showed clear green signals surrounding blue-stained cell nuclei. Conclusion The newly prepared pAb P54 demonstrated reliable specificity and sensitivity and, thus, may have potential applications not only in studies of prion biology but also in the diagnosis of human and experimental rodent prion diseases.
Animals ; Antibodies ; immunology ; Blotting, Western ; Fluorescent Antibody Technique ; Immunization ; Immunohistochemistry ; Mice ; Mice, Knockout ; PrPC Proteins ; immunology ; PrPSc Proteins ; immunology ; Prion Proteins ; immunology ; Recombinant Proteins ; immunology

Antibodies, Viral ; physiology ; Betacoronavirus ; physiology ; Clinical Laboratory Techniques ; Coronavirus Infections ; diagnosis ; Cross Reactions ; physiology ; Enzyme-Linked Immunosorbent Assay ; Fluorescent Antibody Technique, Indirect ; Humans ; Pandemics ; Pneumonia, Viral ; diagnosis ; SARS Virus ; physiology

Blotting, Western ; Conjunctival Diseases ; Dry Eye Syndromes ; Epithelial Cells ; Fluorescent Antibody Technique ; Humans ; Immunohistochemistry ; Inflammation ; Interleukin-6 ; Necrosis ; Phosphorylation ; Real-Time Polymerase Chain Reaction ; RNA, Messenger ; Tears ; Tumor Necrosis Factor-alpha ; Wounds and Injuries