Serum Antibody Tests Research Articles

Clinical Problem-Solving: A 19-Year-Old Woman With Progressive Neurological Decline and Multiple Intracranial Lesions.

The differential diagnosis for multiple intracranial lesions in a young adult is broad and includes demyelinating, neoplastic, and infectious etiologies. In this report, we describe the case of a 19-year-old immunocompetent woman presenting with progressive headaches and aphasia. MRI of the brain revealed multiple, large supratentorial lesions with concentric bands of alternating T2 signal intensities and peripheral contrast enhancement. Cerebrospinal fluid (CSF) analysis was overall bland with negative oligoclonal bands. Serum antibody testing for neuromyelitis optica (NMO) and myelin-oligodendrocyte associated disease (MOGAD) were negative. A broad infectious work-up was also unrevealing. A definitive diagnosis was ultimately obtained after brain biopsy and the patient was started on appropriate therapy. This case highlights a diagnostic framework in evaluating immunocompetent patients presenting with multiple intracranial lesions and progressive neurological decline. The main differential diagnoses for this constellation of radiological and clinical findings are discussed and a literature review is performed on the revealed diagnosis. Lastly, both acute and long-term therapeutic approaches are reviewed.

Diagnosis and Treatment of Membranous Nephropathy in Integrative Medicine

Membranous nephropathy (MN) is a common glomerular disease. The related pathological changes are primarily characterized by the deposition of immune complexes beneath the epithelial cells of the glomerular basement membrane, accompanied by diffuse thickening of the basement membrane. Its etiology and pathogenesis are not fully understood yet; however, they are associated with genetics, infections, tumors, drugs, heavy metals poisoning, environmental pollution, and the loss of immune tolerance. Over 10 target antigens, including the phospholipase A2 receptor (PLA2R) and thrombospondin type 1 domain containing 7A (THSD7A), associated with MN have been identified, each having different clinical implications. Clinical manifestations of MN patients mainly include proteinuria and nephrotic syndrome, with a propensity to form thrombi. Its diagnostic accuracy can be enhanced by combining clinical manifestations, serum antibody testing, and renal biopsy. Proteinuria, estimated glomerular filtration rate (eGFR), and PLA2R antibody levels are vital for the prognostic risk stratification of MN. Low-risk patients primarily undergo non-immunosuppressive treatment (angiotensin-converting enzyme inhibitor [ACEI]/angiotensin II receptor blocker [ARB], sodium-glucose cotransporter 2 inhibitor [SGLT2i], anticoagulants, and traditional Chinese medicine [TCM] treatments), while high-risk patients need to consider using steroids and immunosuppressants, such as cyclophosphamide (CTX), calcineurin inhibitors (CNIs), and anti-cluster of differentiation 20 (anti-CD20) monoclonal antibodies. TCM holds that MN is the imbalance of Fei (lung), Pi (spleen), and Shen (kidney) function, leading to the generation of Neixie such as Shi, Re, Du, and Yu. This disease is difficult to heal because of Shire and Yu. The treatment is based on the use of Jianpi Bushen, simultaneously emphasizing the use of drugs for Qingre Qushi Huoxue. Dialectical use of TCM can obviously improve the clinical response rate and alleviate symptoms such as edema and fatigue by increasing the serum albumin level more rapidly while introducing fewer adverse reactions. Combined with Western medicine, TCM can also reduce toxicity and increase efficiency. This article systematically reviews the etiology, podocyte antigens, clinical manifestations, diagnostic approaches, risk assessment, and integrative medicine therapeutic strategies for MN, aiming to deepen the understanding of MN and guide clinical practice.

A prospective cohort study of pregnancy outcomes following antepartum infection with SARS-CoV-2

ObjectivesOur study aimed to explore the impact of COVID-19 infection on pregnancy outcomes, accounting for the progression of variants, vaccines, and treatment modalities. Study DesignWe performed a prospective longitudinal cohort study at two urban tertiary centers enrolling patients with a confirmed intrauterine singleton pregnancy from December 23, 2020 to July 18, 2022. Patients were evaluated for SARS-CoV-2 infection at enrollment and every trimester using serum antibody testing. The primary outcome was preterm birth. Symptom and treatment data were collected from pregnant patients with COVID-19 infections. Variant strain infection status was determined from local wastewater analysis. Results448 patients were enrolled, and 390 patients were retained through delivery with 159 unexposed and 231 exposed patients, of whom 56 patients (26.0 %) crossed over after enrollment to the exposed cohorts during pregnancy. There was no difference in rates of preterm birth between exposed and unexposed cohorts (14.6 % vs 11.3 %), in deliveries < 34 weeks (1.5 % vs 2.7 %), PPROM, (0.4 % vs 1.3 %), or gestational age at delivery (38.1 vs 38.2). Exposed patients were significantly more likely to be diagnosed with a hypertensive disorder (aOR 2.3, 95 % CI 1.2–4.1), specifically gestational hypertension (aOR 2.8, 95 % CI 1.3––6.0), but not preeclampsia/eclampsia. There were no differences in individual or composite neonatal outcomes. ConclusionsOur study contributed to the understanding of the effects of SARS-CoV-2 infection on pregnancy outcomes, with increased risk of hypertensive disorders of pregnancy but overall, no differences in adverse neonatal outcomes. Regular antenatal PCR and antibody screening allowed for higher detection and inclusion of patients with asymptomatic SARS-CoV-2 infection and effects on maternal and neonatal outcomes.

Pregnancy Outcomes in Patients With Hepatitis C Virus Infection.

To evaluate the risks of adverse maternal and neonatal outcomes associated with pregnancies complicated by hepatitis C virus (HCV) infection. This is a secondary analysis of a multicenter prospective cohort study of HCV infection in pregnancy. Participants were screened for HCV infection with serum antibody tests, and each participant with a positive HCV result (case group) was matched with up to two individuals with negative HCV results (control group) prospectively by gestational age (±2 weeks) at enrollment. Maternal outcomes included gestational diabetes, abruption, preeclampsia or gestational hypertension, cholestasis, and preterm delivery. Neonatal outcomes included hyperbilirubinemia, admission to neonatal intensive care (NICU); small-for-gestational-age (SGA) birth weight; and neonatal infection, defined as sepsis or pneumonia. Models were adjusted for maternal age, body mass index, injection drug use, and maternal medical comorbidities. The 249 individuals in the case group were prospectively matched to 486 individuals in the control group who met eligibility criteria. There were significant differences in demographic characteristics between the groups, including race, socioeconomic markers, education, insurance status, and drug and tobacco use. The frequencies of maternal outcomes of gestational diabetes, preeclampsia, and abruption were similar between the case and control groups. Preterm birth was similar between groups, but neonates born to individuals in the case group were more likely to be admitted to the NICU (45.1% vs 19.0%, adjusted odds ratio [aOR] 2.6, 95% CI, 1.8-3.8) and to have SGA birth weights below the 5th percentile (10.6% vs 3.1%, aOR 2.9, 95% CI, 1.4-6.0). There were no increased odds of hyperbilirubinemia or neonatal infection. Despite no increased odds of preterm birth or other adverse maternal outcomes in adjusted analyses, maternal HCV infection was associated with twofold increased odds of NICU admission and nearly threefold increased odds of SGA birth weight below the 5th percentile.

Overview and Diagnostic Approach in Autoimmune Neurology.

The field of autoimmune neurology is rapidly evolving. This article reviews the epidemiology and pathophysiology as well as current approaches to clinical and paraclinical assessment, testing paradigms, and general principles of treatment. Improved recognition of autoimmune diagnoses among patients who have phenotypically diverse, subacute onset neurologic presentations is facilitated by disease-specific antibody biomarker discovery. These antibodies have varying associations with paraneoplastic causation (from no association to greater than 70% positive predictive value), immunotherapy responses, and outcomes. To simplify assessment in an increasingly complex discipline, neurologic phenotype-specific serum and CSF antibody evaluations are recommended. Clinical trials have led to the approval of monoclonal therapies for neuromyelitis optica spectrum disorder (NMOSD) and are underway for N-methyl-d-aspartate (NMDA) receptor and leucine-rich glioma inactivated protein 1 (LGI1) encephalitides. Autoimmune neurology is now a mainstream subspecialty, consisting of disorders with diverse presentations detectable using antibody testing of serum and CSF. Early and sustained immunotherapy (eg, corticosteroids, intravenous immunoglobulin [IVIg], plasma exchange) is recommended and may be supplemented by immune suppressants (eg, rituximab or cyclophosphamide) to sustain responses and optimize outcomes.

Two Cases of Pediatric Leucine-Rich Glioma-Inactivated Protein-1 Encephalitis: Clinical Course, Challenges, and Implications

BackgroundLeucine-rich glioma-inactivated protein 1 (LGI-1) encephalitis is a rare form of autoimmune limbic encephalitis. Although relatively well documented in adults, pediatric cases are rare and remain poorly understood. MethodsWe reviewed two pediatric cases of LGI-1 encephalitis from a single tertiary care facility retrospectively. The detailed analysis included assessment of the initial presentation, clinical progression, diagnostic challenges, treatments, and outcome. To contextualize the differences between pediatric and adult manifestations of disease, we compared these findings with existing literature. ResultsBoth cases illustrate the diagnostic challenges faced at initial presentation due to the rarity of this diagnosis in children and the absence of characteristic faciobrachial dystonic seizures, which is common in adults. The constellation of neuropsychiatric symptoms and refractory focal seizures led to a high clinical suspicion for autoimmune encephalitis, therefore, both cases were treated empirically with intravenous methylprednisolone. The diagnosis in both cases was confirmed with positive serum antibody testing, reinforcing that LGI-1 antibodies are more sensitive in the serum rather than the cerebrospinal fluid (CSF). Seizure control and improvement in cognitive symptoms was achieved through a combination of immunotherapy and antiseizure medications. ConclusionsThis case series underscores the significance of considering LGI-1 encephalitis in the differential diagnosis of pediatric patients exhibiting unexplained neuropsychiatric symptoms and focal seizures and emphasizes the importance of performing both serum and CSF antibody testing. It is necessary to conduct further research to identify the full range of pediatric presentations and to determine the optimal treatment protocol.

The prognostic value of the Merkel cell polyomavirus serum antibody test: A dual institutional observational study.

Merkel cell carcinoma (MCC) is an aggressive cancer with often poor outcomes. Limited biomarkers exist for predicting clinical outcomes. The Merkel cell polyomavirus (MCPyV) serum antibody test (AMERK) has shown potential for indicating better recurrence-free survival in a single-institution study. The study aimed to evaluate the link between initial AMERK serostatus and survival. Secondary objectives included examining the relationship between initial AMERK titer levels and tumor burden. A retrospective cohort study across two institutions analyzed patients tested with AMERK within 90 days of MCC diagnosis. Regression models assessed the association of survival outcomes with serostatus, considering various factors. The relationship between AMERK titer and tumor burden indicators was evaluated using ANOVA. Significance testing was exploratory, without a fixed significance level. Of 261 MCC patients tested, 49.4% were initially seropositive (titer ≥75). Multivariable analysis showed that seropositivity improved recurrence, event-free, overall, and MCC-specific survival rates. Strong associations were found between initial AMERK titer and clinical, tumor, and nodal stages, tumor size, and disease extent. Notably, improved survival with seropositivity was observed only in patients with localized disease at initial presentation. Circulating antibodies to MCPyV oncoproteins, as indicated by the AMERK test, are linked with better survival in MCC patients with localized disease at presentation. This could enhance patient risk profiling and treatment personalization. The study's retrospective nature and exploratory analysis are key limitations. Merkel cell carcinoma (MCC) is a potentially aggressive skin cancer, and tools to predict patient outcomes are limited. A blood test called anti-Merkel cell panel (AMERK), which checks for specific antibodies related to this cancer, might give us some clues. In this study, we looked at 261 MCC patients who took the AMERK test within 90 days of diagnosis. We found that patients with an initial positive AMERK result tended to have better outcomes, especially if their cancer was in the early stages. However, it is important to note that this study has limitations, including using retrospective data and exploratory analyses.

Effects of Serum Antibody Test Reagent Discontinuation on Diagnosis of Amebiasis in Japan: Interrupted Time-Series Analysis.

Amebiasis is a notifiable infectious disease in Japan, and the number of reported cases had been on the rise, but since the discontinuation of insurance-covered serum antibody testing reagent in 2017, concerns have arisen regarding the decrease in reported cases. This study aimed to investigate changes occurring after discontinuation of the serum antibody test reagent production. We retrospectively analyzed amebiasis cases from January 2014 to December 2019 using the National Center for Epidemiology of Infectious Diseases system. Interrupted time-series regression analysis was used to evaluate trends in weekly amebiasis cases before and after the discontinuation period. The study period was divided into prediscontinuation (2014-2017) and discontinuation (2018-2019) periods. A total of 6,179 amebiasis cases were reported. The average numbers of weekly cases were 21.5 during 2014-2017 and 16.3 during 2018-2019. The frequency of diagnoses decreased in the discontinuation period (prevalence rate ratio = 0.78; 95% CI, 0.67-0.89; P < 0.01). Subgroup analysis showed lower diagnostic rates, particularly for extraintestinal amebiasis (prevalence rate ratio = 0.37; 95% CI, 0.22-0.55; P < 0.01). We observed a significant decrease in the number of reported amebiasis cases per week after discontinuation of the serum antibody test reagent in Japan. Our findings hold significance for both public health policy and practice in Japan, underscoring the requirement for enhanced amebiasis diagnostic tools and strategies. To ensure accurate diagnosis, availability of antibody reagents for serum testing, covered by insurance, should be encouraged.

Isolated Intracranial Hypertension as a Presentation of Pediatric Lyme Borreliosis: A Case Report and Literature Review

BackgroundIt is extremely rare for Lyme borreliosis to present solely with features of increased intracranial pressure. The treatment of pediatric Lyme neuroborreliosis with oral versus intravenous antibiotics remains controversial. MethodsCase report and literature review. ResultsA 13-year-old male presented with five days of binocular diplopia, several weeks of headache, and a history of multiple tick bites six weeks prior. His examination showed a left eye abduction deficit and bilateral optic disc edema. Magnetic resonance imaging (MRI) of the brain with contrast showed tortuosity of the optic nerves, prominence of the optic nerve sheaths, and enhancement of the left fifth and bilateral sixth cranial nerves. Lumbar puncture showed an elevated opening pressure and a lymphocytic pleocytosis. Lyme IgM and IgG antibodies were positive in the serum and cerebrospinal fluid. The patient was treated with intravenous ceftriaxone for two days empirically followed by doxycycline by mouth for 19 days. Symptoms began improving after 48 hours. The strabismus resolved after two weeks, and the papilledema improved slowly with complete resolution at six months. ConclusionsLyme neuroborreliosis can present as isolated intracranial hypertension in the pediatric population; it can be differentiated from idiopathic intracranial hypertension on MRI, and lumbar puncture and can be confirmed with serum antibody testing. Oral doxycycline can be considered for Lyme neuroborreliosis in children.

Accuracy of prostigmin tests in the diagnosis of myasthenia gravis: a meta-analysis.

Myasthenia gravis (MG) is an acquired autoimmune disease diagnosed based on clinical manifestations, muscle fatigue tests, prostigmin tests, serum antibody tests, and neuroelectrophysiological examination. This study conducted a comprehensive search of PubMed, Web of Science, Scopus, Ovid, Embase, Cochrane Library, China National Knowledge Infrastructure, WanFang, Chinese Periodical Database, Chinese Bio-Medicine Database, VIP, and DuXiu Database to identify relevant studies on the accuracy of prostigmin tests for diagnosing MG, covering publications from 1941 to 2021. Ten studies met the inclusion criteria and were included in the meta-analysis. The analysis found no heterogeneity caused by threshold effects but identified heterogeneity due to non-threshold effects. The combined sensitivity was 0.861 (95% CI: 0.831-0.888), and the combined specificity was 0.844 (95% CI: 0.816-0.870). The combined positive likelihood ratio was 5.496 (95% CI: 1.454-20.77), and the combined negative likelihood ratio was 0.237 (95% CI: 0.123-0.455). The area under the curve for diagnostic accuracy was 0.88 (95% CI: 0.84-0.90), with Q* = 0.8520. The combined diagnostic odds ratio was 19.344 (95% CI: 4.327-86.488). In conclusion, the prostigmin test demonstrated good diagnostic value for MG.

Detection of Helicobacter pylori Infection in Human Gastric Fluid Through Surface-Enhanced Raman Spectroscopy Coupled With Machine Learning Algorithms

Diagnostic methods for Helicobacter pylori infection include, but are not limited to, urea breath test, serum antibody test, fecal antigen test, and rapid urease test. However, these methods suffer drawbacks such as low accuracy, high false-positive rate, complex operations, invasiveness, etc. Therefore, there is a need to develop simple, rapid, and noninvasive detection methods for H. pylori diagnosis. In this study, we propose a novel technique for accurately detecting H. pylori infection through machine learning analysis of surface-enhanced Raman scattering (SERS) spectra of gastric fluid samples that were noninvasively collected from human stomachs via the string test. One hundred participants were recruited to collect gastric fluid samples noninvasively. Therefore, 12,000 SERS spectra (n = 120 spectra/participant) were generated for building machine learning models evaluated by standard metrics in model performance assessment. According to the results, the Light Gradient Boosting Machine algorithm exhibited the best prediction capacity and time efficiency (accuracy = 99.54% and time = 2.61 seconds). Moreover, the Light Gradient Boosting Machine model was blindly tested on 2,000 SERS spectra collected from 100 participants with unknown H. pylori infection status, achieving a prediction accuracy of 82.15% compared with qPCR results. This novel technique is simple and rapid in diagnosing H. pylori infection, potentially complementing current H. pylori diagnostic methods.

Quantitative Polymerase Chain Reaction (qPCR)-Based Rapid Diagnosis of Helicobacter pylori Infection and Antibiotic Resistance.

Helicobacter pylori is a major human pathogen thatinfects approximately half of the global population and is becoming a serious health threat due to its increasing antibiotic resistance. It is the causative agent of chronic active gastritis, peptic ulcer disease, and gastric cancer and has been classified as a Group I Carcinogen by the International Agency for Research on Cancer. Therefore, the rapid and accurate diagnosis of H. pylori and the determination of its antibiotic resistance are important for the efficient eradication of this bacterial pathogen. Currently, H. pylori diagnosis methods mainly include the urea breath test (UBT), the antigen test, the serum antibody test, gastroscopy, the rapid urease test (RUT), and bacterial culture. Among them, the first three detection methods are noninvasive, meaning they are easy tests to conduct. However, bacteria cannot be retrieved through these techniques; thus, drug resistance testing cannot be performed. The last three are invasive examinations, but they are costly, require high skills, and have the potential to cause damage to patients. Therefore, a noninvasive, rapid, and simultaneous method for H. pylori detection and drug resistance testing is very important for efficiently eradicating H. pylori in clinical practice. This protocol aims to present a specific procedure involving the string test in combination with quantitative polymerase chain reaction (qPCR) for the rapid detection of H. pylori infection and antibiotic resistance. Unlike bacterial cultures, this method allows for easy, rapid, noninvasive diagnosis of H. pylori infection status and drug resistance. Specifically, we used qPCR to detect rea for H. pylori infection and mutations in the 23S rRNA and gyrA genes, which encode resistance against clarithromycin and levofloxacin, respectively. Compared to routinely used culturing techniques, this protocol provides a noninvasive, low-cost, and time-saving technique to detect H. pylori infection and determine its antibiotic resistance using qPCR.

Rituximab for the Treatment of Anti-glomerular Basement Membrane Disease with Isolated Diffuse Alveolar Hemorrhage: A Case Report.

Anti-glomerular basement membrane (GBM) disease with isolated diffuse alveolar hemorrhage (DAH) is rare. We herein report a 91-year-old man admitted with hypoxia and diagnosed with anti-GBM disease with DAH based on positive bronchoalveolar lavage and serum antibody test results. There was no renal involvement. Although remission was achieved using glucocorticoids and plasmapheresis, the patient experienced DAH relapse one week after the last plasmapheresis. Rituximab 375 mg/m2 was administered 4 times weekly; thereafter, DAH relapse was not observed, and the glucocorticoid dosage was tapered. Rituximab was thus effective in treating anti-GBM disease with isolated DAH in an extremely elderly patient.

Neuronal autoantibodies in a sample of Egyptian patients with drug-resistant epilepsy

BackgroundEpilepsy is one of the most common and chronic neurological diseases. About one-third of epilepsy patients do not achieve seizure freedom despite adequate therapy with antiseizure medications (ASMs) and develop drug-resistant epilepsy (DRE). Autoimmunity is increasingly being recognized as a cause of epilepsy in those patients. Some cases are associated with antibodies against several target antigens, including neuronal extracellular proteins as well as intracellular structures. In such patients, immunotherapy may be highly effective. This study aimed to investigate the presence of NMDA-R, AMPA1-R, AMPA2-R, CASPR2, LGI1, GABAB-R, and GAD65 autoantibodies in a sample of Egyptian patients with new-onset DRE; also, to assess the clinical, cerebrospinal fluid (CSF), electroencephalogram (EEG), and radiological characteristics of those patients. Twenty-five patients with recent onset DRE were recruited from the department of Neurology at Ain Shams University (ASU) hospitals. All patients underwent serum and CSF antibody testing using cell-based assay (CBA) at the Immunology unit of the Clinical pathology laboratory at ASU hospitals. This is beside routine CSF analysis, EEG and MRI brain with contrast.ResultsOut of 25 patients with recent onset DRE, one (4%) patient tested positive to anti-NMDA-R antibodies and another one (4%) tested positive to anti-GAD 65 in both serum and CSF. Although the remaining 23 patients tested negative for the 7 autoantibodies, yet 92% of them achieved either seizure freedom or more than 50% reduction in the frequency of seizure and 84% had marked improvement in seizure-associated symptoms after receiving immunotherapy trial. Also, evidence of neuroinflammation was detected in the CSF and MRI brain of the majority of those patients.ConclusionsAutoimmunity should be considered as a possible etiology of new-onset DRE. It is essential to provide insight into the clinical phenotypes and other associated features of those patients, as there are probably numerous patients who are not positive for one of the available antibodies via clinical laboratory testing. In addition to early diagnosis, early treatment and empirical immunotherapy trial based on the clinical judgment is crucial and is likely to improve outcomes with near-complete seizure freedom.

Bovine hypodermosis is highly prevalent in Kazakhstan: Results of a first serological study.

Recent information on the occurrence of bovine hypodermosis in Kazakhstan is limited to the results of a few clinical studies in the northern and eastern regions. A first serological study aimed to obtain more data on its geographical distribution and to estimate the prevalence in this country. Serum samples collected from 891 dairy cows on 30 dairy farms in eight Kazakh provinces during the winter season 2015/2016 were examined for antibodies to Hypoderma spp. first-stage larval antigen using a commercially available enzyme-linked immunosorbent assay (IDEXX Bovine Hypodermosis Serum Antibody Test). Overall, 73.6% (95% confidence interval: 70.6%-76.5%) of the cows sampled were seropositive for Hypoderma, and antibody-positive cows were found in 28 of 30 farms and in seven of eight provinces. The results suggest a high prevalence of bovine hypodermosis in Kazakhstan, for which the socioeconomic changes in agriculture and village life following the country's independence are considered to be responsible.

Insights on genetic characterization and pathogenesis of a GI-19 (QX-like) infectious bronchitis virus isolated in China

Infectious bronchitis virus (IBV) causes respiratory diseases in chickens, incurring great losses to the poultry industry worldwide. In this study, we isolated an IBV strain, designated as AH-2020, from the chickens vaccinated with H120 and 4/91 in Anhui, China. The sequence homology analysis based on the S1 gene revealed that AH-2020 shares low similarities with the 3 vaccine strains, namely, H120, LDT3-A, and 4/91 (78.19, 80.84, and 81.6%, respectively). Phylogenetic analysis based on the S1 gene revealed that AH-2020 clustered with the GI-19 type. Furthermore, protein modeling revealed that the mutations in the amino acids in AH-2020 were mainly located in the N-terminal domain of S1 (S1-NTD), and the pattern of deletion and insertion mutations in the S1 protein may have influenced the structural changes on the surface of S1. Further, approximately 7-day-old SPF chickens were inoculated with AH-2020 at 106.0 EID50. These chickens exhibited clinical signs of the infection such as listlessness, huddling, and head-shaking, accompanied by depression and 40% mortality. Serum antibody test demonstrated that in response to the AH-2020 infection, the antibody level increased the fastest at 7 dpi, with virus shedding rate of cloaca being 100% at 14 dpi. The viral titer in various tissues was detected using hematoxylin and eosin staining and immunohistochemistry, which revealed that AH-2020 infection can damage the kidney, trachea, lung, cecal tonsil, and bursa of Fabricius. Our study provided evidence that the GI-19-type IBV is undergoing more complex mutations, and effective measures are urgently needed to prevent the spread of these variant strains.

Evaluation and application of a milk antibody ELISA for assessing the prevalence and incidence of bovine tuberculosis in dairy herds in Hubei Province, China

Bovine tuberculosis (bTB) is a chronic zoonotic disease that is endemic in China. Current in-vitro tests for bTB are mainly based on blood assays. Collection of samples results in some stress to the sampled cattle and associated economic losses for the herd owner. This study was designed to investigate the relationship between milk and serum antibody tests for bTB in dairy cows using 85 cows with milk and corresponding blood samples. Totally 4,395 milk samples were used to assesse the apparent (test) prevalence and incidence of bTB using the milk antibody ELISA. The association between levels of bTB milk antibody and milk quality was also evaluated. Milk and serum antibody tests showed a good correlation with a 87.5% (95% CI: 61.7%, 98.4) positive agreement and 98.7% (95% CI: 95.4, 99.8) negative agreement. The animal level lactoprevalence ranged from 0.3% (95% CI: 0, 1.2) to 33.3% (95% CI: 26.6, 40.6) in different farms and the incidence rate ranged from 0 head/cow-month (95% CI: 0, 0.02) to 0.04 head/cow-month (95% CI: 0.02, 0.07). Twenty percent of sampled farms met the criteria for bTB control in China. The prevalence on large-scale farms was lower (p < 0.001) than on small farms. The bTB milk antibody levels had a negative correlation with milk yield and a positive correlation with somatic cell count (SCC), milk protein percentage (MPP) and percentage of total solids (TS). According to this research, milk ELISA could be used as a supplement of blood samples to assist in the surveillance for bTB and for alerting control and eradication of bTB.

A Cluster of Paragonimiasis with Delayed Diagnosis Due to Difficulty Distinguishing Symptoms from Post-COVID-19 Respiratory Symptoms: A Report of Five Cases

Paragonimiasis caused by trematodes belonging to the genus Paragonimus is often accompanied by chronic respiratory symptoms such as cough, the accumulation of sputum, hemoptysis, and chest pain. Prolonged symptoms, including respiratory symptoms, after coronavirus disease 2019 infection (COVID-19) are collectively called post-COVID-19 conditions. Paragonimiasis and COVID-19 may cause similar respiratory symptoms. We encountered five cases of paragonimiasis in patients in Japan for whom diagnoses were delayed due to the initial characterization of the respiratory symptoms as a post-COVID-19 condition. The patients had consumed homemade drunken freshwater crabs together. One to three weeks after consuming the crabs, four of the five patients were diagnosed with probable COVID-19. The major symptoms reported included cough, dyspnea, and chest pain. The major imaging findings were pleural effusion, pneumothorax, and nodular lesions of the lung. All the patients were diagnosed with paragonimiasis based on a serum antibody test and peripheral blood eosinophilia (560-15,610 cells/μL) and were treated successfully with 75 mg/kg/day praziquantel for 3 days. Before diagnosing a post-COVID-19 condition, it is necessary to consider whether other diseases, including paragonimiasis, may explain the symptoms. Further, chest radiographic or blood tests should be performed in patients with persistent respiratory symptoms after being infected with COVID-19 to avoid overlooking the possibility of infection.

Clinical Application of SARS-CoV-2 IgM and IgG Antibody Detection Using the Colloidal Gold Immunochromatography Assay

Objective: The COVID-19 pandemic, which was caused by SARS-CoV-2, has had a significant effect on global public health, economies, and societies worldwide. Serum antibody testing is a critical method for the diagnosis of COVID-19 and can complement RT-PCR in the diagnosis of COVID-19 patients; however, the performance of rapid antibody assays in the clinical setting has not been established. Methods: Rapid antibody assays were evaluated by investigating 296 COVID-19-positive individuals and 542 negative individuals confirmed by clinical diagnosis. The clinical diagnostic results were used as controls to evaluate the sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), kappa, and 95% confidence interval (CI) of the rapid tests. Result: IgM-positivity had a sensitivity of 86.1% and specificity of 99.1%. IgG-positivity had a sensitivity of 86.5% and specificity of 98.7%. The sensitivity of combined IgM- and IgG-positivity in clinically confirmed patients was 73.1% in the early stage (1-7 days after symptom onset) and reached 99% 15 days after symptom onset. The concordance between rapid antibody-positive tests and clinical diagnosis-positivity had a kappa value of 0.93. In addition, the false-positive rate of IgM and IgG combined nucleic acid detection was 30% in the early stage. Conclusion: The combined use of IgM and IgG could serve as a more suitable alternative detection method for patients with COVID-19. The rapid antibody test can be considered as an excellent supplementary approach for detecting SARS-CoV-2 in clinical application.

Pediatric Anti-NMDA Receptor Autoimmune Encephalitis Masquerading as Depression: A Case Report From a Tertiary Care Center in South India

Abstract Autoimmune disorders are now widely recognized as playing a larger role in encephalitis than previously thought. The most common disorder appears to be anti-N-methyl-d-aspartate receptor (NMDAR) encephalitis. Psychological symptoms, memory difficulties, and autonomic instability are all part of the complicated presentation and are being considered an important differential diagnosis for children presenting with acute behavioral disturbances. We present the case of a 17-year-old girl, who presented with a 1.5-year history of psychiatric symptoms such as pervasive low mood, decreased ability to concentrate on her studies, academic decline, memory disturbances along with poor social interaction, decreased self-esteem, and ideas of guilt. This was accompanied by altered biological functions. Within a week, the symptoms changed dramatically, with labile mood, over familiarity, over identification, déjà vu, auditory hallucinations and anxiety symptoms, nonspecific somatic symptoms such as fever, vomiting, and neurological symptoms including seizures and dyskinesia. Diagnosis of anti-NMDAR encephalitis was made by electroencephalography and serum antibody testing. Symptom improvement was noted with five cycles of plasmapheresis and injection of rituximab. Psychiatric manifestations are common, and child and adolescent psychiatrists are frequently the first to be contacted for patients with anti-NMDAR encephalitis. There is, therefore, an increasing need for them to become aware of the disorder and consider it in their differential diagnosis. A better prognosis can be achieved with appropriate evaluation by a multi-disciplinary team.