Direct Immunofluorescence Research Articles

Pemphigoid Gestationis - literature review

Introduction and Objective: Pemphigoid gestationis (PG) is a rare, self-limiting autoimmune disorder, typically appearing in the second or third trimester of pregnancy. It can lead to postpartum exacerbations, and studies suggest an increased risk of preterm birth and the development of Graves' disease in the mother. The aim of this article is to gather the latest information on pemphigoid gestationis. Review Methods: A review of studies available in the PubMed database was conducted using the keywords "pemphigoid gestationis" and "dermatoses of pregnancy" in order to find publications from the last 8 years. Brief Description of the State of Knowledge: Pemphigoid gestationis (PG) is characterized by the production of IgG1 antibodies against bullous pemphigoid antigen 180 (BP180). The primary symptom of PG is intense itching, which often occurs before skin lesions develop. Diagnosis is typically confirmed through direct immunofluorescence (DIF) of perilesional skin. Treatment focuses on relieving itching and preventing new blister formation, usually starting with topical corticosteroids for mild cases, while systemic corticosteroids are reserved for more severe presentations. Recent research indicates that biologic therapies may also offer effective management options for PG. Summary: The authors highlight the need for further research due to the limited sample sizes in existing studies, as well as the potential complications during pregnancy and long-term health effects.

Factors Influencing the Clinical Course of Bullous Pemphigoid among Geriatric Patients: A Pilot Study

Background and Objectives: Bullous pemphigoid (BP) is the most common autoimmune blistering disease affecting mainly elderly patients. Still, little is known about the pathogenesis of pruritus in BP or the factors that affect the clinical course of the disease. This study aimed to evaluate the factors influencing the clinical course of BP among older patients. Materials and Methods: A retrospective analysis of medical records of 55 patients with BP hospitalized in the dermatology department in 2015–2021 was conducted. The study focused on preliminary diagnosis, medical history, clinical examination (characteristics and location of cutaneous changes), laboratory investigation, and direct and indirect immunofluorescence. Results: Analysis of laboratory results in combination with the clinical course of BP showed that red blood cell count, hemoglobin, and hematocrit values were negatively associated with a risk of erosions and erythema, while MCHC values were positively correlated with a risk of associated pruritus. A correlation was found between neurological diseases and an increased risk of erosions. Conclusions: We have shown that age and neurological conditions, including stroke, affect the clinical course of BP. Further studies on a larger group of patients should be conducted to investigate the different factors affecting the clinical aspect of BP and to understand the relationship between them.

Direct immunofluorescence in bullous disorders: A mini-review

Background: Immunofluorescence microscopy is an invaluable tool for different lesions in dermatopathology. These lesions include bullous lesions, vasculitis, and connective tissue disorders/systemic lupus erythematosus. In this review, we take a look at bullous disorders. Some of these diagnoses are not possible on routine histopathology alone and require immunofluorescence for confirmation. Different diseases can be diagnosed according to the immunoglobulins/complements, sites of deposition (dermo-epidermal / intercellular spaces / dermal), and their patterns (linear, granular). Knowing the exact type of lesion can help guide treatment accordingly.

Atypical Presentation of Adult-Onset Hydroa Vacciniforme with Direct Immunofluorescence Positivity—A Case Report

Atypical Presentation of Adult-Onset Hydroa Vacciniforme with Direct Immunofluorescence Positivity—A Case Report

Utility of Immunofluorescence in Immune-Mediated Vesiculobullous Lesions of Skin

Bullous lesions may be due to various causes, including bullous pemphigoid, pemphigus vulgaris, linear IgA disease, connective tissue disorders, and other rare vesico-bullous skin diseases. Though histopathology can help narrow down possible diagnoses, direct immunofluorescence is required for a definite diagnosis based on positivity patterns of different immunoglobulins. In this study, 47 cases of clinically suspected immune mediated vesiculo-bullous diseases (IMVBD) were confirmed with histopathology. Females were more commonly affected and the age range was from 10 to 93 years. Among these cases, 23 were diagnosed as pemphigus vulgaris, l6 as bullous pemphigoid, 3 each as pemphigus foliaceus and linear IgA disease. DIF, including testing for c1q, was instrumental for the diagnosis of the disease in order for the patient to get appropriate treatment.

Comparison of BIOCHIP Mosaic Based Indirect Immunofluorescence and Oral Direct Immunofluorescence in Patients with Oral Mucosal Pemphigus

Comparison of BIOCHIP Mosaic Based Indirect Immunofluorescence and Oral Direct Immunofluorescence in Patients with Oral Mucosal Pemphigus

Enhancing diagnostic accuracy: Direct immunofluorescence assay as the gold standard for detecting Giardia duodenalis and Cryptosporidium spp. in canine and feline fecal samples

The enteric protozoan parasites Giardia duodenalis and Cryptosporidium spp. are common cause of diarrhea in pet dogs and cats, affecting primarily young animals. This comparative study evaluates the diagnostic performance of conventional and molecular methods for the detection of G. duodenalis and Cryptosporidium spp. infection in dogs and cats.The compared diagnostic assays included merthiolate-iodine-formalin (MIF) method, lateral flow immunochromatography rapid test (ICT) and real-time PCR; using direct immunofluorescence assay (DFA) as golden standard. The study included the analysis of 328 fecal samples from different dog (n = 225) and cat (n = 103) populations.According to DFA, the overall prevalence of G. duodenalis was 24.4% (80/328, 95% CI: 19.8–29.4), varying from 11.6% (12/103, 95% CI: 6.2–19.5) in cats to 30.2% (68/225, 95% CI: 24.3–36.7) in dogs. The overall prevalence of Cryptosporidium spp. was 4.0% (13/328, 95% CI: 2.1–6.7), varying from 2.9% (3/103, 95% CI: 0.6–8.3) in cats to 4.4% (10/225, 95% CI: 2.1–8.0) in dogs. MIF was only used for the detection of G. duodenalis, which was identified by this method in 22.7% of dogs and 7.8% of cats, respectively. DFA was the most sensitive technique for detecting G. duodenalis in samples from dogs and cats (p-value: < 0.001), followed by real-time PCR. Identification of Cryptosporidium infections was most effectively accomplished by the combination of DFA and PCR technique (p-value: < 0.001). In addition, epidemiological (sex, age, origin) and clinical (fecal consistency) variables were collected to assess their potential associations with an increased likelihood of infection by G. duodenalis and/or Cryptosporidium spp. Breeder dogs were more likely to harbor G. duodenalis infection (p-value: 0.004), whereas female cats were significantly more infected with Cryptosporidium (p-value: 0.003).In conclusion, DFA (alone or in combination with PCR) has been identified as the most accurate and cost-effective method for detecting G. duodenalis and Cryptosporidium spp. in fecal samples from pet dogs and cats. This highlights their importance in both veterinary and clinical settings for enabling prompt treatment and preventing potential transmission to humans.

Intensity grading of kidney biopsy direct immunofluorescence IgG image via semantically enhanced feature network

The intensity of direct immunofluorescence IgG imaging for kidney biopsy is an important reference index for the diagnosis of common chronic kidney diseases (CKD) such as membranous nephropathy (MN). Although this index is widely used in diagnosing membranous nephropathy, the intensity levels are currently judged only by the subjective perception of fluorescence luminance in pathological images through physicians’ naked eyes. Therefore, consistent intensity level classification cannot be achieved. To address this issue, this paper proposes a Preprocessing Semantically Enhanced Feature image classification method. The segmentation network is used to segment the original kidney biopsy direct immunofluorescence IgG images to isolate the diseased glomeruli. These segmented glomeruli images are then compared with the original glomeruli images to standardize the kidney biopsy direct immunofluorescence images. Simultaneously, considering the characteristics of small inter-class differences and large intra-class differences in fine-grained images, a semantically enhanced feature image classification model is employed to automatically classify the intensity of the standardized images. The method was evaluated on a constructed real clinical dataset, and the experimental results demonstrated that the proposed method achieved high classification accuracy on this dataset. The source code is made available on https://github.com/SnowRain510/PSEF-NET

Rabies in free-ranging capybaras (Hydrochoerus hydrochaeris) on Anchieta Island, Ubatuba, Brazil.

Between December 2019 and January 2020, three cases of rabies were reported in free-ranging capybaras on Anchieta Island, Ubatuba-SP, Brazil. This 8.28km² island is located 540m offshore from the mainland. Two of the capybaras exhibited signs of hindlimb paralysis, and one was found dead. Rabies was diagnosed using the direct fluorescent antibody test (dFAT), while RT-qPCR and phylogenetic analysis of nucleotide sequences confirmed the presence of the vampire bat rabies virus (RABV) strain. Although no visible bat bite marks were found on the capybaras, vampire bats are known to inhabit the island. Other wildlife tested negative for rabies during this period, and no further rabies outbreaks have been observed since. Environmental changes and human activities, such as the disturbance of bat roosting sites, may have contributed to the incident. The detection of rabies in capybaras suggests a potential spillover from a vampire bat reservoir. Further investigation is needed to determine whether capybaras act as dead-end hosts or play a role in maintaining the rabies transmission cycle.

Diagnostic utility of direct immunofluorescence test panels for cutaneous vasculitis: A scoping review

AbstractBackgroundDue to the immune‐mediated nature of non‐infectious cutaneous vasculitis, skin biopsy specimens are often submitted for direct immunofluorescence (DIF) testing when vasculitis is considered clinically. However, evidence regarding the clinical value of DIF has not been rigorously appraised.ObjectiveIn this scoping review, we aimed to systematically evaluate the peer‐reviewed literature on the utility of DIF in vasculitis to assist with the development of appropriate use criteria by the American Society of Dermatopathology.MethodsTwo electronic databases were searched for articles on DIF and vasculitis (January 1975–October 2023). Relevant case series involving more than or equal to three patients, published in English, and with full‐text availability were included. Additional articles were identified manually via reference review. Due to study heterogeneity, findings were analyzed descriptively.ResultsOf 255 articles identified, 61 met the inclusion criteria. Cumulatively representing over 1000 DIF specimens, several studies estimated DIF sensitivity to be 75%. While vascular immunoglobulin A (IgA) deposits on DIF were associated with renal disease, other systemic associations were inconsistent. Vascular IgG deposition may be overrepresented in ANCA‐associated vasculitis. Granular vascular and epidermal basement membrane zone Ig deposition differentiated hypocomplementemic from normocomplementemic urticarial vasculitis. Few studies have assessed the added value of DIF over routine microscopy alone in vasculitis.ConclusionsThis scoping review discovered that DIF testing for vasculitis has been performed not only for diagnostic confirmation of vasculitis but also for disease subtype classification and prediction of systemic associations. Future studies on test sensitivity of DIF compared to that of histopathology are needed.

The first description of mucous membrane pemphigoid induced by enalapril maleate: a case report

BackgroundMucous membrane pemphigoid (MMP) is an autoimmune blistering disease (AIBD). Some reports suggest that it has a drug-related pathogenesis especially anti-hypertensive drug.Case presentationA 67-year-old man with a 7-year history of essential hypertension was prescribed enalapril maleate for 5 months. He presented at our department with pain, ulcers, and blisters on the oral mucosa. We performed clinical, histopathology, and direct immunofluorescence examinations, and findings were consistent with the diagnostic criteria for MMP. Consequently, we consulted with the cardiovascular physician and agreed to discontinue the enalapril maleate replacing it with irbesartan/hydrochlorothiazide tablets and topical corticosteroid therapies instead. The lesions healed without recurrence.ConclusionsABID induced by antihypertensive drugs have been reported, and enalapril maleate has been implicated as an antihypertensive agent that may trigger AIBDs, such as MMP. This case highlights the potential relationship between antihypertensive drugs and MMP, of which clinicians should be aware to accurately diagnose and promptly relieve patients’ pain.

Periodic acid-schiff staining: A counterpart of the immunoreactivity seen by direct immunofluorescence in bullous pemphigoid

Periodic acid-schiff staining: A counterpart of the immunoreactivity seen by direct immunofluorescence in bullous pemphigoid

Navigating Blistering Pathways: A Case Study of Dyshidrosiform Bullous Pemphigoid

Dyshidrosiform Bullous Pemphigoid (DBP) is a rare type of autoimmune blistering disease, mainly affecting elderly individuals. Causing pruritic blisters on the palms and soles, it can be challenging to differentiate from other conditions such as pompholyx. A case study of an 89-year-old patient with DBP is presented, emphasizing the importance of accurate diagnosis through techniques like direct immunofluorescence (DIF) staining. Treatment typically involves corticosteroids, monoclonal antibodies, dapsone, or immunosuppressants. Improved awareness and understanding of DBP are crucial for improved patient outcomes.

Bovine respiratory syncytial virus: First identification in eastern Algeria based on direct immunofluorescence and ELISA tests

Bovine respiratory syncytial virus: First identification in eastern Algeria based on direct immunofluorescence and ELISA tests

Performance of the Vetscan Imagyst in point-of-care detection of Giardia duodenalis in canine fecal samples.

Giardia duodenalis is a common parasite of the gastrointestinal tract of dogs, with an especially high prevalence in dogs <1-y-old. Methods for detecting G. duodenalis are point-of-care (POC) tests such as lateral-flow tests or fecal flotation. The Vetscan Imagyst (Zoetis) is a new POC device for the detection of G. duodenalis in fecal samples using zinc sulfate flotation, automated slide scanning, and image recognition with artificial intelligence. Vetscan results are the number of Giardia cysts per coverslip. We compared the performance of the Vetscan and another POC test (SNAP Giardia test; Idexx) with a direct immunofluorescence assay (IFA) performed in a specialized parasitology laboratory as the reference test. We included 164 dogs <19-mo-old. We used pooled fecal samples from 3 defecations gained within 2-3 d and tested the repeatability of the Vetscan by triplicate measurement. Compared to IFA, Vetscan had a diagnostic sensitivity of 88.4% and specificity of 98.1%; SNAP had a diagnostic sensitivity of 74.4% and specificity of 98.1%. A variation coefficient of 67.0% was determined for the Vetscan results. The performance of the Vetscan is acceptable for the qualitative evaluation of fecal samples (Giardia positive or negative), and the device can be used by untrained personnel. Given its high variation coefficient, we do not recommend the Vetscan for monitoring the number of cysts.

Oral Lichen Planus: A Narrative Review Navigating Etiologies, Clinical Manifestations, Diagnostics, and Therapeutic Approaches.

Background/Objectives: Oral Lichen Planus (OLP) is a common immune-mediated inflammatory disorder affecting the oral mucosa, impacting 0.5% to 2% of the global population, primarily middle-aged women. Immunological dysregulation is a key factor in OLP's pathogenesis, involving CD4+ T helper and CD8+ T cytotoxic cells. The World Health Organization (WHO) classifies OLP as a potentially malignant disorder, with a risk of oral squamous cell carcinoma (OSCC) developing in up to 2% of lesions. This narrative review aims to provide a comprehensive overview of the etiopathogenesis, clinical manifestations, diagnostic criteria, and therapeutic strategies for OLP, informing clinical practice and guiding future research. Methods: A review of the literature from the PubMed and Google Scholar databases was conducted up to December 2023, focusing on studies addressing the etiopathogenesis, diagnosis, clinical manifestations, and treatment of OLP. Results: OLP's pathogenesis is driven by immune dysregulation, with CD4+ and CD8+ cells playing crucial roles. Clinically, OLP presents as reticular, erosive, bullous, and plaque-like lesions. Diagnosis relies on clinical examination, histopathology, and direct immunofluorescence. Recent advancements in diagnostic markers and imaging techniques have improved detection and monitoring. Treatment primarily involves corticosteroids, but novel therapies such as curcumin, retinoids, and laser therapy are increasingly used for their effectiveness and reduced side effects. These treatments show promise in symptom reduction and recurrence prevention, although long-term data are needed. Conclusions: Regular screenings and biopsies are essential due to OLP's likelihood of malignant transformation. This study urges further investigation into long-term results, improved diagnostic techniques, and evidence-based treatment regimens.

Diagnostic value of direct immunofluorescence testing in the evaluation of alopecia: A single-institution retrospective cohort study of 346 specimens

Diagnostic value of direct immunofluorescence testing in the evaluation of alopecia: A single-institution retrospective cohort study of 346 specimens

The discovery of novel variants reveals the genetic diversity and potential origin of Seoul orthohantavirus.

Seoul orthohantavirus (SEOV) has been identified as one of the main causative agents of hemorrhagic fever with renal syndrome (HFRS) in China. The virus was found circulating in rodent populations in almost all provinces of the country, reflecting the wide distribution of HFRS. Here, using the direct immunofluorescence assay (DFA) and real-time quantitative reverse transcription PCR (qRT-PCR) approach, we performed screening in 1784 small mammals belonging to 14 species of three orders captured in the main areas of HFRS endemicity in Yunnan province (southwestern China) and identified 37 SEOV-positive rats (36 Rattus norvegicus and 1 Rattus tanezumi). A 3-year surveillance of HFRS epidemics and dynamics of rodent reservoir density and virus prevalence implied a potential correlation between them. The subsequent meta-transcriptomic sequencing and phylogenetic analyses revealed three SEOV variants, among which two are completely novel. The ancestral character state reconstruction (ACSR) analysis based on both novel variants and documented strains from 5 continents demonstrated that SEOV appeared to originate near the southwestern area (Yunnan-Kweichow Plateau) of China, then could spread to other regions and countries by their rodent carriers, resulting in a global distribution today. In summary, these data furthered the understanding regards genetic diversity and the potential origin for SEOV. However, the expanding endemic foci in the province suggest that the virus is spreading over a wider region and is much more diverse than previous depicted, which means that increased sampling is necessary.

Ocular Mucous Membrane Pemphigoid Presenting as Recurrent Pterygium.

The aim of this series was to report recurrent pterygium as a presenting feature of ocular mucous membrane pemphigoid (oMMP). A retrospective review was performed, and patients with biopsy positive oMMP who presented with recurrent pterygia were included. Data on the demographic profile, clinical characteristics, and details of the surgical intervention were collected. A total of 5 patients with recurrent pterygium were included. All the patients were men. The median age was 63 years. History of pterygium surgery was present in 8/10 eyes (80%), of which 6 eyes (60%) developed a recurrent pterygium. A symblepharon was present in 4/6 eyes (67%). Forniceal shortening was present in 10/10 (100%) eyes. All eyes were subjected to a conjunctival biopsy for direct immunofluorescence, of which 9 eyes (90%) had positive results consistent with oMMP. Systemic immunomodulatory therapy (IMT) with either methotrexate or azathioprine was initiated in all 5 patients. Recurrent pterygium can be a presenting feature of oMMP. The presence of symblepharon formation or forniceal shortening, especially in the fellow eye, warrants a conjunctival biopsy and prompt initiation of IMT to prevent disease progression.

Diagnosis of autoimmune bullous dermatoses: Comparative analysis of immunohistochemical staining using C4d, C3d, IgG, and IgG4 in lesional tissues and perilesional frozen skin samples

Immunohistochemical staining with immunoglobulins and complements may aid the diagnosis of patients whose clinical and histological findings are consistent with autoimmune bullous dermatoses (AIBD). We aimed to investigate the diagnostic value of immunohistochemical markers in lesional biopsy and perilesional frozen samples in AIBD. We included 136 cases from whom lesional biopsies and perilesional samples for direct immunofluorescence (DIF) examination were collected with a preliminary diagnosis of AIBD between January 2019 and January 2023. All diagnoses were reconfirmed by evaluating the clinical, histopathological, and serological findings and DIF results (C3, IgG, IgA, or IgM positivity compatible with the clinical diagnosis) altogether, although DIF results were considered a priority. After confirming the diagnoses, the samples were categorized as AIBD or the others. The perilesional tissues obtained for DIF simultaneously with skin biopsy and stored at −80 °C were thawed, and FFPE tissues were prepared. We performed immunohistochemical staining (C4d, C3d, IgG, and IgG4) on FFPE tissues of both lesional and perilesional samples. Strong, linear, or granular staining patterns at the dermoepidermal junction or the intraepidermal blistering space were considered positive in line with the diagnosis of the case. Cases other than AIBD were used as negative control tissues to assess the specificity of immunohistochemical markers. Of the 136 cases, 52 were diagnosed with AIBD. In lesional samples, the sensitivity of C4d, C3d, IgG, and IgG4 was 80.6 %, 69.4 %, 75 %, and 5.7 % with corresponding specificity of 100 %, 98.7 %, 89.6 %, and 97.4 %, respectively in pemphigoid diseases compared to a sensitivity of 18.2 %, 9.1 %, 70 %, and 9.1 % and specificity of 98.7 %, 100 %, 89.6 %, and 97.4 %, respectively in pemphigus diseases. In frozen samples, we detected expression in a limited number of cases. The sensitivity of C4d, C3d, IgG, and IgG4 was 8.7 %, 2.2 %, 19.4 %, and 2.2 %, with corresponding specificity of 100 %, 100 %, 98.5 %, and 98.6, respectively. There was a none to slight concordance rate between the IHC results of lesional tissues and perilesional frozen samples. Kappa coefficients for C4d, C3d, IgG, and IgG4 were 0.120 (P = 0.029), 0.111 (P = 0.050), 0.203 (P = 0.003), and - 0.15 (P = 0.846), respectively. Immunohistochemical staining with C4d, C3d, IgG, and IgG4 on biopsy samples collected from lesions may guide the diagnosis of AIBD, thereby eliminating the need for an additional biopsy and accelerating the diagnostic process.