Direct Immunofluorescence Research Articles

Dermoscopic and histopathologic findings in diagnosing postpartum pemphigoid gestationis

Background: Pemphigoid gestationis (PG) is an uncommon autoimmune vesiculobullous skin disorder associated with pregnancy, that occurs during mid-to-late pregnancy and immediate postpartum period. The diagnosis of PG is based on histopathology and direct immunofluorescence. Dermoscopy is a non-invasive diagnostic tool that provides a connection between macroscopic clinical dermatology and microscopic dermatopathology. Case Illustration: We reported a case of a 22-year-old primigravida woman with postpartum PG. This PG case was diagnosed clinically, dermoscopically, and histopathologically. Discussion: Since PG is thought to be a variation of the bullous pemphigoid (BP), the two resemble each other clinically and immunologically. The well-defined structures with brown-black dots in the central, yellowish translucent areas, follicular openings, peri-eccrine and perifollicular pigmentations, and a distorted pigment network were the dermoscopic findings of PG. To date, there is no literature about the dermoscopic features of PG. Conclusion: Dermoscopy is a simple non-invasive tool that can assist in making a rapid diagnosis, as well as in evaluating the prognosis, observing the response to treatment, and helping to determine the appropriate lesion and location for histopathological examination. We recommend that the dermoscopic features of PG in our case as a dermoscopic picture of PG.

Rabies virus circulation in a highly diverse bat assemblage from a high-risk area for zoonoses outbreaks in the Brazilian Amazon

Bats are the second most diverse order of mammals and play a central role in ecosystem dynamics. They are also important reservoirs of potentially zoonotic microorganisms, of which rabies virus is the most lethal among the bat-transmitted zoonotic pathogens. Importantly, recent outbreaks of human rabies have been reported from the Brazilian Amazon. Here we present a survey of bat species and rabies virus (RABV) circulation in a bat assemblage in the Marajó region, northern Brazil. Using data from mist-net captures and bioacoustic sampling, 56 bat species were recorded along the Jacundá River basin over a 10-day expedition in November 2022. For the investigation of RABV, we used the direct fluorescent antibody test (DFAT) and the rapid fluorescent focus inhibition test (RFFIT). In total, 159 bat individuals from 22 species were investigated for RABV. Five adults of the common vampire bat, Desmodus rotundus, showed RABV-specific antibodies in serum samples. Additionally, we report on local residents with injuries caused by D. rotundus bites and the occurrence of colonies of non-hematophagous bats from different species roosting inside human residences. This scenario raises concerns about the risks of new cases of human rabies and other zoonotic diseases associated with bats in the region and highlights the need for epidemiological surveillance and mitigation measures to prevent outbreaks of emerging infectious diseases.

Artificial intelligence in autoimmune bullous dermatoses

Dermatologists treating patients with autoimmune bullous dermatoses (AIBDs), as well as the patients themselves, encounter challenges at every stage of their interaction, including dermatologic and comorbidities assessment, diagnosis, prognosis evaluation, treatment, and follow-up monitoring. We summarize the current and potential future clinical applications of artificial intelligence (AI) in the field of AIBDs. Recent research and AI models have demonstrated their potential to enhance or may already be contributing to advancements in every phase of the comprehensive diagnosis and personalized treatment process in AIBDs, providing patients, clinicians, and administrators with valuable support. Image recognition AI systems might assist precise clinical diagnoses of various diseases, including AIBDs, and could offer consistent and reliable scoring of disease severity. Automated and standardized AI-assisted laboratory methods could improve the accuracy and decrease the time and cost of gold-standard tests such as direct and indirect immunofluorescence. The studies and tools discussed in this contribution, although in the early stages, might be a small precursor to a transformative shift in the way we take care of patients with chronic skin diseases, including AIBDs.

High serum total IgE levels correlate with urticarial lesions and IgE deposition in perilesional skin of bullous pemphigoid patients: An observational study.

Background In the pathophysiology of bullous pemphigoid, besides IgG, there has been evidence that supports the role of IgE antibodies. However, there have been no studies to evaluate total serum IgE levels or detect IgE deposits in the skin of Vietnamese patients. Aim To analyse the association between IgE levels in the serum and disease severity as well as eosinophils and IgE basement membrane zone (BMZ) deposition in Vietnamese bullous bullous pemphigoid patients. Methods A single-centre observational research on 35 newly diagnosed and untreated bullous bullous pemphigoid patients. Total serum IgE levels were analysed using enzyme-linked immunosorbent assay (ELISA). For controls, we collected sera of 30 pemphigus patients and 30 elderly patients with pruritus. Perilesional skin biopsies underwent direct immunofluorescence (DIF) staining, with biopsies of pemphigus patients as controls. Results Elevated total serum IgE was observed in 60% of bullous pemphigoid patients, the percentage in the pemphigus group and pruritus group was 20% and 40%, respectively. The mean total serum IgE level among the bullous pemphigoid group was higher than that of the pemphigus group (123.3 ± 102.4 IU/mL vs. 64.3 ± 45.1 IU/mL, p = 0.010). Total serum IgE levels of bullous pemphigoid patients correlated with higher eosinophil counts (r = 0.61; p = 0.018) and urticaria/erythema (U/E) Bullous Pemphigoid Disease Area Index (BPDAI) score (r = 0.50; p = 0.035). Among 35 bullous pemphigoid patients, 5 patients showed positive IgE DIF staining, accounting for 14.3%. Higher serum IgE levels correlated with the deposition of IgE in patients' perilesional skin (p = 0.037). Limitations Due to the rarity of bullous pemphigoid, the effect of the COVID-19 pandemic, and self-treatment issues in Vietnam, we could not recruit a larger number of participants. Conclusions Total serum IgE values correlated with urticarial lesions and IgE deposition in perilesional skin of Vietnamese bullous pemphigoid patients. IgE autoantibodies present in the skin of bullous pemphigoid patients support the role of IgE in bullous pemphigoid pathogenesis.

A monoclonal antibody that recognizes a unique 13-residue epitope in the cytoplasmic tail of HLA-E

The Class I MHC molecule (MHC-I) HLA-E presents peptides that are derived from the signal sequences, either those of other MHC-I products, or of viral type I membrane glycoproteins. Monoclonal antibodies with proven specificity for HLA-E, and with no cross-reactions with other MHC-I products, have yet to be described. To obtain anti-HLA-E-specific antibodies suitable for a range of applications, we generated monoclonal antibodies against a unique feature of HLA-E: its cytoplasmic tail. We created an immunogen by performing an enzymatically catalyzed transpeptidation reaction to obtain a fusion of the cytoplasmic tail of HLA-E with a nanobody that recognizes murine Class II MHC (MHC-II) products. We obtained a mouse monoclonal antibody that recognizes a 13-residue stretch in the HLA-E cytoplasmic tail. We cloned the genes that encode this antibody in expression vectors to place an LPETG sortase recognition motif at the C-terminus of the heavy and light chains. This arrangement allows the site-specific installation of fluorophores or biotin at these C-termini. The resulting immunoglobulin preparations, labeled with 4 equivalents of a fluorescent or biotinylated payload of choice, can then be used for direct immunofluorescence or detection of the tag by fluorescence or by streptavidin-based methods. We also show that the 13-residue sequence can serve as an epitope tag, independent of the site of its placement within a protein’s sequence. The antibody can be used diagnostically to stain for HLA-E on patient tumor samples, it can be used as an antibody-epitope tag for extracellular proteins, and it enables research into the unique role of the cytoplasmic tail of HLA-E.

Cutaneous lupus subtypes

A broad spectrum of dermatologic manifestations, known as cutaneous lupus erythematosus (CLE), may or may not be linked to the development of systemic disease. There are numerous subtypes of cutaneous lupus, such as acute cutaneous lupus (ACLE), subacute cutaneous lupus (SCLE), and chronic cutaneous lupus (CCLE). CCLE encompasses lupus tumidus, chilblain cutaneous lupus, LE profundus (LEP), and discoid lupus erythematosus (DLE). In order to diagnose these diseases, it is necessary to accurately classify the subtype. This is achieved through a combination of physical examination, laboratory studies, histology, antibody serology, and occasionally direct immunofluorescence, while also excluding systemic disease. The treatment of cutaneous lupus involves the provision of appropriate topical and systemic agents, as well as patient education regarding solar protection. In cases where the disease is pervasive, scarring, or treatment-refractory, systemic agents are recommended. In this chapter, we address the classification and diagnosis of the diverse subtypes of CLE and offer a comprehensive update on therapeutic management.

Direct Immunofluorescence in Cutaneous Vesiculobullous Lesions: A Cross-sectional Study in a Tertiary Care Center

Introduction: Cutaneous noninfectious autoimmune vesiculobullous diseases are a wide variety of lesion. They can show clinical and histopathological overlap, posing diagnostic challenges. Clinically, vesiculobullous lesions might not present with typical morphology and distribution in all cases. The specific histomorphological changes are observed only in an early and intact bulla. Immunofluorescence (IF) is a histochemical staining technique which detects antibodies in the tissue and body fluids. IF an adjuvant to histopathology is considered as gold standard in the diagnosis of vesiculobullous diseases. Methodology: A two-year retrospective cross-sectional descriptive study was conducted in the department of pathology, in a tertiary care center from January 2018 to December 2019. Paraffin embedded hematoxylin and eosin slides were retrieved from the archives and analyzed. Biopsies received in Michel’s medium were utilized for immunofluorescence study. Results: A total of 67 cases with Vesiculobullous lesions were analysed. The most common lesion diagnosed was Bullous Pemphigoid (BP) (29 cases -46.7%), followed by Pemphigus Vulgaris (PV) (19 cases- 30.6%). The highest number of cases were noted in the 7th decade, with a slight female preponderance. Sixteen out of 19 cases of pemphigus vulgaris and 28 out of 29 cases of bullous pemphigoid showed positive histomorphological correlation with IF. The PPV for pemphigus vulgaris was 100% and sensitivity was 84.2%, and in bullous pemphigoid, both the PPV and sensitivity was 96.5%. Higher concordance was noted between Histopathology and IF diagnosis in cases of BP in comparison to PV. Conclusion: Vesiculobullous lesions are heterogeneous in nature and can have clinical and histopathological overlap, posing diagnostic challenges. IF is considered gold standard and is necessary for the diagnosis in every case. A combined clinical, histopathological and IF examination is the best approach to accurate diagnosis. Keywords Bullous, Pemphigus, Vesiculobullous, Direct Immunofluorescence

State-of-the-art diagnosis of autoimmune blistering diseases.

Autoimmune blistering disorders (AIBDs) are a heterogeneous group of approximately a dozen entities comprising pemphigus and pemphigoid disorders and dermatitis herpetiformis. The exact diagnosis of AIBDs is critical for both prognosis and treatment and is based on the clinical appearance combined with the detection of tissue-bound and circulating autoantibodies. While blisters and erosions on the skin and/or inspectable mucosal surfaces are typical, lesions may be highly variable with erythematous, urticarial, prurigo-like, or eczematous manifestations. While direct immunofluorescence microscopy (IFM) of a perilesional biopsy is still the diagnostic gold standard, the molecular identification of the major target antigens opened novel therapeutic avenues. At present, most AIBDs can be diagnosed by the detection of autoantigen-specific serum antibodies by enzyme-linked immunosorbent assay (ELISA) or indirect IFM when the clinical picture is known. This is achieved by easily available and highly specific and sensitive assays employing recombinant immunodominant fragments of the major target antigens, i.e., desmoglein 1 (for pemphigus foliaceus), desmoglein 3 (for pemphigus vulgaris), envoplakin (for paraneoplastic pemphigus), BP180/type XVII collagen (for bullous pemphigoid, pemphigoid gestationis, and mucous membrane pemphigoid), laminin 332 (for mucous membrane pemphigoid), laminin β4 (for anti-p200 pemphigoid), type VII collagen (for epidermolysis bullosa acquisita and mucous membrane pemphigoid), and transglutaminase 3 (for dermatitis herpetiformis). Indirect IFM on tissue substrates and in-house ELISA and immunoblot tests are required to detect autoantibodies in some AIBD patients including those with linear IgA disease. Here, a straightforward modern approach to diagnosing AIBDs is presented including diagnostic criteria according to national and international guidelines supplemented by long-term in-house expertise.

Diagnostic yield of direct immunofluorescence testing in esophageal biopsies: A retrospective single-center cohort study of 99 consecutive cases

Diagnostic yield of direct immunofluorescence testing in esophageal biopsies: A retrospective single-center cohort study of 99 consecutive cases

PEMPHIGUS HERPETIFORMIS TREATED EFFECTIVELY WITH DERMOCORTICOIDS ALONE

Introduction: Pemphigus herpetiformis is a rare form of pemphigus. Case Report: A patient presented with a well-limited erythematous-squamous and crusty dermatosis with a ring-like arrangement, with vesiculo-bullous lesions with a herpetiform grouping of the trunk and 4 limbs. Histological and direct immunofluorescence findings were consistent with pemphigus. The diagnosis of pemphigus herpetiformis (PH) was made. The patient was treated with dermocorticoids with lasting remission. Discussion: Pemphigus herpetiformis is a particular form of pemphigus characterised by a clinical picture resembling that of dermatitis herpetiformis and an immunopathological appearance similar to that of pemphigus. It generally has a good prognosis. Treatment is based on dapsone and/or general corticosteroid therapy.

#1591 Analysis of microvesicles and their relationship with oxidative stress as biomarkers of cardiovascular damage in chronic kidney disease

Abstract Background and Aims Chronic kidney disease (CKD) is associated with a higher incidence of cardiovascular diseases. These diseases are preceded by endothelial dysfunction and alterations in coagulation systems. One of the challenges of research in this field is the search for diagnostic and predictive biomarkers of cardiovascular pathology. Our hypothesis is that endothelial dysfunction and cardiovascular risk could be evidenced by the increased release of endothelial microvesicles (EMVs) and platelet microvesicles (PMVs), as well as a greater expression of tissue factor (TF). We also propose a relationship between the release of microvesicles and the oxidative stress observed in these patients. The aim of the study was to analyze the levels of MVEs and MVPs, the expression of FT and its relationship with pro-oxidant and antioxidant parameters as possible early biomarkers of cardiovascular and thrombotic risk in different stages and treatments of CKD. Method It is a cross-sectional study consisted of 116 patients (40 with advanced chronic disease (CKD), 40 undergoing hemodialysis (HD) and 36 undergoing peritoneal dialysis (PD)), as well as 17 healthy subjects (CT). Microvesicle phenotyping was performed by direct immunofluorescence and flow cytometry in plasma isolated by centrifugation from peripheral blood. The analysis of oxidative stress parameters was carried out by spectrophotometry, after isolation of plasma and mononuclear and polymorphonuclear leukocytes by means of a ficoll gradient. Results Patients on PD have higher plasma PMVs levels (p = 0.0005 vs ACKD and p = 0,0002 vs HD), while those on HD and PD have higher levels of EMVs compared to ACKD (p = 0,0001 and p = 0,0125, respectively). FT expression in PMVs is lower in HD (p < 0.0001 vs ACKD) and FT expression in EMVs is lower in HD and PD compared to ACKD (p = 0,0004 and p= 0.0033, respectively) (Fig. 1). Patients with CKD have a higher activity of pro-oxidant enzymes (XO, GPx), as well as high levels of lipid peroxidation by-products (TBARS-MDA) and lower activity of antioxidant enzymes (GSH, CAT, SOD) at the plasma and cellular level. A positive relationship has been observed between pro-oxidant parameters and the release of MVP and MVE, as well as the expression of FT (Table 1). Patients with cardiovascular events during the years of follow-up have higher levels of FT expressed in microvesicles, and long-term survival decreases in patients with elevated FT levels. Conclusion Patients with CKD have higher plasma levels of PMVs and EMVs and higher FT expression, related to a state of oxidative stress. These parameters could be considered as biomarkers for predicting, diagnosing, and prognostic cardiovascular events in CKD.

#1782 Clinicopathological study of renal limited pauci-immune vasculitis and its short-term outcome: a single centre observational study

Abstract Background and Aims Pauci immune crescentic glomerulonephritis, is a leading cause of RPGN. The majority of patients with PICGN have glomerular diseases as a part of a systemic small vessel vasculitis, a minority may present as renal-limited vasculitis. In north-east India, there are still no major studies in this group of patients. Therefore, our study involving north-east Indian population constitutes an effort to prospectively study the clinico-pathological feature of patients with PICGN and assess the short-term outcome. Method This single-centre, prospective, observational, study was conducted over 12 months at the Department of Nephrology, Gauhati Medical College. All renal biopsy-proven patients with pauci-immune renal vasculitis were included, excluding those with secondary vasculitis. Baseline characteristics and laboratory data were recorded, and disease activity was assessed using the Birmingham Vasculitis Activity Score. The ANCA tests were performed using a standardised essay for both indirect immunofluorescence assay and antigen-specific ELISA. The renal biopsy specimen obtained was evaluated by light microscopy and direct immunofluorescence. The sample size was calculated based on the prevalence of pauci-immune glomerulonephritis, and data were analysed using SPSS. Results The study involved 24 patients, predominantly females (70.83%), aged 14-65 years, presenting predominantly with pedal oedema and oliguria. Laboratory findings showed varying levels of haemoglobin, total count, platelet count, creatinine, and 24-hour urine protein. 50% of the patients were (MPO) positive, 33.3% were (PR3) positive while 16% were ANCA negative. Renal biopsy analysis showed a majority with mixed class according to the Berden classification. Treatment involved induction with Methylprednisolone and Cyclophosphamide, with dialysis administered to 58.3% of patients. At six months, 36.3% had a stable GFR, and 50% were on maintenance hemodialysis. Factors predicting renal loss included oliguria, dialysis at presentation, and fibrous/fibrocellular crescents. The best predictor of renal outcome was serum creatinine at presentation. Conclusion Pauci-immune CrGN is a severe disease affecting a wide age range. Early diagnosis and treatment initiation are crucial for better outcomes, including lower ESRD risk and relapse rates. Prognostic factors include baseline serum creatinine levels and fibrous crescents. Optimising treatment regimens may improves outcomes.

Reprofiling synthetic glucocorticoid-induced leucine zipper fusion peptide as a novel and effective hair growth promoter.

Hair is a biofilament with unique multi-dimensional values. In human, in addition to physiologic impacts, hair loss and hair related disorders can affect characteristic features, emotions, and social behaviors. Despite significant advancement, there is a dire need to explore alternative novel therapies with higher efficacy, less side effects and lower cost to promote hair growth to treat hair deficiency. Glucocorticoid-induced leucine zipper (GILZ) is a protein rapidly induced by glucocorticoids. Studies from our group and many others have suggested that a synthetic form of GILZ, TAT-GILZ, a fusion peptide of trans-activator of transcription and GILZ, can function as a potent regulator of inflammatory responses, re-establishing and maintaining the homeostasis. In this study, we investigate whether TAT-GILZ could promote and contribute to hair growth. For our pre-clinical model, we used 9-12 week-old male BALB/c and nude (athymic, nu/J) mice. We applied TAT-GILZ and/or TAT (vehicle) intradermally to depilated/hairless mice. Direct observation, histological examination, and Immunofluorescence imaging were used to assess the effects and compare different treatments. In addition, we tested two current treatment for hair loss/growth, finasteride and minoxidil, for optimal evaluation of TAT-GILZ in a comparative fashion. Our results showed, for the first time, that synthetic TAT-GILZ peptide accelerated hair growth on depilated dorsal skin of BALB/c and induced hair on the skin of athymic mice where hair growth was not expected. In addition, TAT-GILZ was able to enhance hair follicle stem cells and re-established the homeostasis by increasing counter inflammatory signals including higher regulatory T cells and glucocorticoid receptors. In conclusion, our novel findings suggest that reprofiling synthetic TAT-GILZ peptide could promote hair growth by increasing hair follicle stem cells and re-establishing homeostasis.

Incidence of human rabies following bite or exposure to laboratory confirmed rabid animals

Background: Rabies is one of the important endemic fatal zoonotic viral disease afflicting humans and animals in Punjab, India. The present study investigated the incidence of rabies in humans bitten/exposed to laboratory confirmed rabid animals, as well as incidence after use of vaccine or rabies immunoglobulin (RIG) and clinico-epidemiological studies. Methods: A study was conducted during August 2021 to September 2022 on forty (40) rabies suspected animals presented to diagnose rabies by direct fluorescent antibody test (dFAT) at rabies diagnostic laboratory (RDL), Guru Angad Dev Veterinary and Animal Sciences University (GADVASU), Punjab, India. A detailed questionnaire was prepared for obtaining information about exposure/bite of humans by rabid animals, death of humans, demographic and epidemiological information of victims. Results: Out of total forty (40) suspected rabies cases, 30(75%) were found positive for rabies by dFAT. Laboratory confirmed rabies (LCR) incidence was 60.80% and 21.73% in stray and pet dogs, respectively. All pet dogs were vaccinated but no stray dog was vaccinated. The LCR incidence in buffaloes and cattle was 77.77% and 100%, respectively. Further in humans exposed to rabid animals (59), males were at more risk than females. The human rabies incidence was 3.38% (2/59). Highest incidence of dog bites in adult males on lower limb was observed from urban stray dogs (60.80%) followed by children. Post exposure vaccination was given to 98.3% humans exposed to rabid animals. Human’s rabies in two cases was due to no vaccination or RIG. Conclusions: Vaccination is an important step in controlling rabies in India. There is a need for integrated and comprehensive management of street dogs and bite management.

Absence of Epidermal Antibodies in Stevens-Johnson Syndrome/Toxic Epidermal Necrolysis Patients but Beware of Single Positive Results.

Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are rare and potentially life-threatening mucocutaneous blistering diseases that clinically can resemble autoimmune bullous diseases. Moreover, it has been shown that autoantibodies against epidermal proteins are present in SJS/TEN. To establish the presence of antibodies against desmosomal and hemidesmosomal proteins in confirmed SJS/TEN patients. Serum of SJS/TEN patients diagnosed based on clinical criteria, e.g., epidermal detachment with erosions and severe mucosal lesions, (suspicion of) a culprit drug, and matching histologic results was evaluated by various techniques, e.g., indirect immunofluorescence on monkey esophagus, salt split skin and rat bladder, immunoblotting (IB) and immunoprecipitation (IP), ELISAs against desmogleins and BP180, keratinocyte footprint assay, and keratinocyte binding assay. A total of 28 patients were included in this study, 15 men and 13 women with a mean age of 56 years. In most patients, none of the serological tests were positive. In two patients, an elevated DSG3 titer was found suspicious for pemphigus vulgaris. Three patients had elevated NC16a titers, suggesting bullous pemphigoid. However, in all these patients, no other tests were positive and in these patients, the biopsy for direct immunofluorescence showed no evidence for an autoimmune bullous disease. Three patients showed reactivity against rat bladder rat bladder; these were, however, completely negative for A2ML1, envoplakin, and periplakin in the IB as well as the IP. Serological analysis for desmosomal and hemidesmosomal antibodies is reliable to rule an autoimmune bullous disease in patients with suspected SJS/TEN. However, one should not rely on one single test method since false positive results can occur. Moreover, this study also makes it less plausible that antibodies against desmosomal and/or hemidesmosomal components are involved in the pathogenesis of SJS/TEN.

Autoimmunity and epithelial dysplasia in patients with oral lichenoid diseases.

The primary objective of this study was to explore relationship between autoimmunity and epithelial dysplasia in patients with oral lichenoid diseases. A total of 66 patients with oral lichen planus (OLP), 35 with oral lichenoid lesion (OLL), and 85 with oral lichenoid drug reaction (OLDR) were enrolled. OLP, OLL, and OLDR were diagnosed following the definitions of the modified World Health Organization criteria, except for the absence of epithelial dysplasia. All patients underwent diagnostic incisional biopsy and adjunctive direct immunofluorescence assays. An indirect immunofluorescence assay was conducted to determine the antinuclear antibody (ANA) positivity. OLP and OLDR patients with epithelial dysplasia demonstrated higher prevalence of serum ANA positivity compared to those without epithelial dysplasia. Elevated serum levels of high sensitivity-C reactive proteins were observed in the OLP, OLL, and OLDR patients with epithelial dysplasia. In the DIF analysis, patients with epithelial dysplasia in the OLP exhibited a higher prevalence of C3 deposition in the basement membrane zone. This study proposed that autoimmunity may contribute to elevating levels of focal and chronic systemic inflammation, potentially influencing abnormal wound healing and development of dysplastic changes in the oral epithelium among patients with oral lichenoid disease.

Retrospective study of laboratory-based surveillance of rabies in wild and domestic animals in the southern United States, 2010-2021.

We performed a retrospective study of all case submissions for the rabies virus (RABV) direct fluorescent antibody test (DFAT) requested of the Tifton Veterinary Diagnostic and Investigational Laboratory (Tifton, GA, USA) between July 2010 and June 2021. Submitted were 792 samples from 23 animal species from 89 counties in Georgia, and 4 neighboring counties in Florida, 1 in South Carolina, and 1 in Alabama. In 13 (1.6%) cases, the DFAT result was inconclusive; 779 (98.4%) cases had a conclusive (positive or negative) test result. Of these 779 cases, 79 (10.1%) tested positive across 10 species. The remaining 700 (89.9%) cases were negative. The main reason for submission for RABV testing was human exposure to a potentially rabid animal in 414 (52.3%) cases. Among the 79 positive cases, 74 (93.7%) involved wildlife; raccoons (51 cases; 68.9%) were the primary host confirmed with RABV infection, followed by skunk and fox (8 cases each; 10.8%), bobcat (5 cases; 6.8%), and bats (2 cases; 2.7%). Only 5 domestic animals (6.3% of the positive cases) tested positive during our study period; one from each of the bovine, canine, caprine, equine, and feline species. Hence, the sylvatic cycle plays the predominant role in circulating RABV infection in our study area.

Granular C3 dermatosis-A report of two cases and a mini-review of literature.

Granular C3 dermatosis (GCD) is characterized by bullous, erythematous, and eczematous skin lesions similar to dermatitis herpetiformis, and granular deposition of complement C3 and C5b-9 along the epidermal basement membrane zone (BMZ) by direct immunofluorescence (IF). Here, we present two cases of GCD with different clinical features. Case 1, a 49-year-old man, showed pruritic blisters and erythema of the extremities. Case 2, a 53-year-old woman, showed severely pruritic papules, erythema, and erosions on the entire body with scattered blisters, mainly on the lower extremities. Both patients showed mild eosinophilia on blood tests, subepidermal blisters and prominent eosinophilic infiltration in the upper dermis on histopathological examination, and granular BMZ deposition of C3, but not of immunoglobulins or other complement components, on direct IF. No circulating autoantibodies were detected on enzyme-linked immunosorbent assays, chemiluminescent enzyme immunoassays, indirect IF using 1 mol/L NaCl-split normal human skin, or immunoblotting. Diagnosis of GCD was made in both cases. Case 1 was successfully treated with topical steroids, oral minocycline, and nicotinamide without any recurrence of symptoms. Case 2 was treated with oral steroids and showed remarkable improvement, although mild pruritic papules remained. We reviewed 30 reported GCD cases, including the two cases presented here, since Hashimoto etal. first described GCD in 2016. GCD should be more widely recognized, and further accumulation and validation of cases are required.

Evaluation of LN34 Pan-Lyssavirus RT-qPCR assay for rabies diagnosis in Brazil

Rabies, a fatal zoonotic viral disease affecting mammals, including humans, remains a significant global health concern, particularly in low-income countries. The disease, primarily transmitted through infected animal saliva, prompts urgent diagnosis for timely post-exposure prophylaxis (PEP). The gold standard diagnostic test, direct fluorescent antibody test (dFAT), while sensitive, suffers from limitations such as subjective interpretation and high costs. As a confirmatory technique, the LN34 Pan-Lyssavirus RT-qPCR assay has emerged as a promising tool for universal Lyssavirus detection. This study evaluated its performance using 130 rabies virus isolates representing eleven Brazilian variants and 303 clinical samples from surveillance operations. The LN34 assay demonstrated 100% sensitivity and 98% specificity compared to dFAT. Additionally, it detected all samples, including those missed by dFAT, indicating superior sensitivity. The assay's specificity was confirmed through Sanger nucleotide sequencing, with only a minimal false-positive rate. Comparative analysis revealed higher accuracy and concordance with dFAT than traditional rabies tissue culture infection tests (RTCIT). False-negative RTCIT results were attributed to low viral load or suboptimal sampling. These findings underscore the LN34 assay's utility as a confirmatory technique, enhancing rabies surveillance and control in Brazil. Its widespread adoption could significantly improve diagnostic sensitivity, crucial for effective PEP and public health interventions.

Comparative performance evaluation of four different methods for diagnosing Giardia infection in dogs and zoonotic assemblages’ identification

Giardia duodenalis (syn. G. intestinalis or G. lamblia) is a parasitic protozoan that infects the upper intestinal tract of a broad range of hosts, including humans and domestic animals. Thus, it has raised concerns about the public health risk due to companion animals. Recently, with the improvement of living standards and increasing contacts between pets and humans, the zoonotic transmission of Giardia has dramatically increased. From a genetic point of view, G. duodenalis should be viewed as a complex species that includes eight different species-specific genetic assemblages. The laboratory diagnosis is mainly based on the finding of microscopic cysts in stool samples by coprological examination. Other methods include the detection of antigens, immunoassays or PCR protocols, which allow the identification of Giardia assemblages. The study aimed to compare the performance of Direct Fluorescence Antibody test (DFA), zinc sulfate flotation technique (ZnSO4), rapid diagnostic test (RDT), end-point PCR amplification (PCR) for the detection of Giardia and to identify the concerning assemblages in a canine population from Central Italy. Direct fluorescence antibody test is the reference standard for laboratory diagnosis of Giardia in fecal samples from dogs, despite the microscopic examination after flotation remains the most useful method in many veterinary diagnostic centers. The present findings demonstrate the high performance of DFA and ZnSO4 in detecting Giardia, while RDT may be useful as alternative or complementary method to the DFA and ZnSO4. PCR performance was low, but it allowed determining Giardia B zoonotic assemblage in 25% of the PCR-positive specimens (15 out of 60), while the remaining PCR-positive isolates belonged to the dog-specific assemblage C. The 26% prevalence of G. duodenalis detected by DFA in owned dogs and the identification of potentially zoonotic assemblages underline the potential risk for public health and indicate frequent cross-species transmission of the parasite between humans and dogs.