Diagnostic performance of rapid antigen test for COVID-19 and the effect of viral load, sampling time, subject's clinical and laboratory parameters on test accuracy.

BACKGROUND: Egypt was among the first 10 countries in Africa that experienced COVID-19 cases. The sudden surge in the number of cases is overwhelming the capacity of the national healthcare system, particularly in developing countries. Central to the containment of the ongoing pandemic is the availability of rapid and accurate diagnostic tests that could pinpoint patients at early disease stages. In the current study, we aimed to (1) Evaluate the diagnostic performance of the rapid antigen test (RAT) "Standard™ Q COVID-19 Ag" against reverse transcriptase quantitative real-time PCR (RT-qPCR) in eighty-three swabs collected from COVID-19 suspected individuals showing various demographic features, clinical and radiological findings. (2) Test whether measuring laboratory parameters in participant's blood would enhance the predictive accuracy of RAT. (3) Identify the most important features that determine the results of both RAT and RT-qPCR. METHODS: Diagnostic measurements (e.g. sensitivity, specificity, etc.) and receiver operating characteristic curve were used to assess the clinical performance of "Standard™ Q COVID-19 Ag". We used the support vector machine (SVM) model to investigate whether measuring laboratory indices would enhance the accuracy of RAT. Moreover, a random forest classification model was used to determine the most important determinants of the results of RAT and RT-qPCR for COVID-19 diagnosis. RESULTS: The sensitivity, specificity, and accuracy of RAT were 78.2, 64.2, and 75.9%, respectively. Samples with high viral load and those that were collected within one-week post-symptoms showed the highest sensitivity and accuracy. The SVM modeling showed that measuring laboratory indices did not enhance the predictive accuracy of RAT. CONCLUSION: "Standard™ Q COVID-19 Ag" should not be used alone for COVID-19 diagnosis due to its low diagnostic performance relative to the RT-qPCR. RAT is best used at the early disease stage and in patients with high viral load.

Sublingual Versus Subcutaneous Immunotherapy as regards Efficacy and Safety in Respiratory Allergic Patients.

Subcutaneous immunotherapy (SCIT) is a well-established treatment modality for allergic patients that has been successfully used for many decades. Sublingual immunotherapy (SLIT) was introduced over the last 20 years as a safer alternative to SCIT with no single case of mortality has ever been reported with it. The aim of this study was to evaluate the efficacy and safety of SLIT versus SCIT in treating respiratory allergic patients. This study was a non-randomized controlled trial including 72 patients suffering from respiratory allergy to house dust mites (HDM) (Dermato-phagoidesfarinae and Dermato-phagoide-spteronyssinus) and date palm pollen (Phoenix dactylifera, Pho). The patients were subjected to full detailed allergy history taking, symptoms and medication scores calculation, skin prick test, Peak Expiratory Flow Rate (PEFR) for asthmatic patients, specific IgE test for HDM allergen. Patients received either SLIT or SCIT, then symptoms and medication scores, PEFR and specific IgE for HDM allergen were reassessed after 6 months of immunotherapy. Any adverse reactions were also recorded. The results showed that patients received either SLIT or SCIT showed a highly significant improvement in symptoms and medication scores with a highly significant improvement in PEFR, while specific IgE levels were not significantly changed. Local adverse reactions were noticed only with SCIT. We conclude that both modalities of treatment were equally effective in treatment of respiratory allergic patients to house dust mites and date palm pollen but SLIT had a more safety profile than SCIT.

House dust mites among allergic patients at the Allergy and Immunology Unit, Zagazig University: an immunologic and serologic study.

In the twenty-first century, the occurrence of allergic diseases has increased. Prevention and control of house dust mites (HDMs) are required as they play a major role in allergic conditions. The present work aimed to detect HDM allergy (Dermatophagoides pteronyssinus and Dermatophagoides farinae) among allergic patients attending the Allergy and Immunology Unit, Zagazig University. Ninety-six patients with a history of allergic diseases were included in this study. They were examined for allergy to D. pteronyssinus and D. farinae using different diagnostic tools: the skin prick test (SPT) and measurement of specific IgE antibodies to HDM allergen extracts. Ninety-six allergic patients were recruited in this study [60 females (62.5%) and 36 males (37.5%) aged between 5-60 years]. SPT (81.2 and 79.2%) and IgE (70.9 and 75%) gave positive results for both D. pteronyssinus and D. pteronyssinus, respectively. The common risk factors were use of cotton bedding > 10 years old, older homes > 20 years, crowded homes, family history, home dampness and homes at the ground floor. It was concluded that allergies to D. pteronyssinus and D. farinae contribute to allergic diseases in Zagazig City. Use of the SPT and IgE level is a promising diagnostic tool in the diagnosis of D. pteronyssinus and D. farinae.

Serum Thymus and Activation Regulated Chemokine (TARC), IL- 18 and IL-18 Gene Polymorphism as Associative Factors with Atopic Dermatitis.

Atopic dermatitis (AD) is a worldwide chronic inflammation of skin.Many factors and chemokines play role in pathogenesis of AD. Identifying the reliable biomarkers to diagnose and assess severity of AD is important. In this study we aimed to find a reliable biomarker to determine the severity of AD and monitor treatment as well as, examining the possible association between IL-18 gene [rs 187238] promoter polymorphism and AD disease. The study included 30 Egyptian patients with AD and 30 healthy controls. Patients were clinically evaluated according to SCORAD scoring system. For each subject levels of Thymus and activation regulated chemokine (TARC), IL-18, total IgE and Lactate dehydrogenase enzyme (LDH) in serum were measured and Polymorphism in IL-18 gene was analyzed using restriction fragment length polymorphism (RFLP). Patients were reevaluated after treatment. Serum levels of TARC, IL-18, IgE and LDH were significantly higher in patients than controls, and were associated with high SCORAD score. G allele was risk factor with OR 2.31 (1.10- 4.85) and significant p-value < 0.05 for AD. GG genotype was significantly associated with elevated serum levels of TARC, IL-18 and IgE. After treatment serum level of TARC showed significant decrease and was associated with low SCORAD score. We concluded that TARC, IL-18, total IgE and LDH are potential markers of severity in AD. G allele in IL-18 gene [rs 187238] is risk factor for AD while C allele is considered protective. TARC is also a reliable marker formonitoring treatment.

Serum Anti-TPO and TPO Gene Polymorphism as a Predictive Factor for Hidden Autoimmune Thyroiditis in Patient with Bronchial Asthma and Allergic Rhinitis.

Thyroid peroxidase (TPO) is the key enzyme in the biosynthesis of thyroid hormones T3 and T4. Autoimmune thyroiditis is a common disorder affecting 10% of population worldwide. A key feature of autoimmune thyroiditis is the presence of anti TPO antibodies, and some mutation of the TPO gene. Association between autoimmune thyroiditis and other autoimmune disorders has been reported but little is known about association with allergic diseases. In this study, we aimed to evaluate frequency of hidden autoimmune thyroiditis among allergic patient and examine possible relationship between anti-TPO levels and polymorphism at the TPO gene A2173/C exon 12 and different types of allergens. The study included 50 adult Egyptian patients with allergic rhinitis and /or bronchial asthma and 50 controls. For each subject, thyroid stimulating hormone (TSH), thyroxin 4 (T4) and Triiodothyronine (T3) hormones were measured. Anti-thyroid peroxidase (anti-TPO) level was detected by ELISA; and TPO gene polymorphism 2173A>C exon 12 was analyzed using restriction fragment length polymorphism (RFLP). Skin prick test was done to assess allergic response in patients. Serum levels of T3, T4 and TSH did not show any statistical significant difference between patients and groups. However, mean serum anti-TPO level was statistically higher in patients than controls, and correlated positively with body mass index, age, diastolic blood pressure, suggesting higher prevalence of hidden autoimmune thyroiditis in allergic patients than in control group. 2173A>C Genotyping revealed that the frequency of C allele is increased in the patient group. C allele represents a risk factor with odds ratio of 2.37 (1.035-5.44) and a significant P value <0.05. It is concluded that TPO 2173A>C polymorphism may be considered as a risk factor for developing autoimmune thyroiditis in patients with allergic rhinitis and asthma and that these patients should regularly be checked for hidden thyroiditis.

Seroprevalence of Helicobacter pylori infection among family members of infected and non-infected symptomatic children.

This study determined the prevalence of seropositivity of anti-H. pylori IgG antibodies, and evaluated some socio-epidemiologic characteristics among family members of infected and non-infected symptomatic children. One hundred children with upper gastrointestinal symptoms without previous H. pylori eradication treatment were prospectively studied by both upper endoscopy with histopathological biopsies examination, and serum anti-H. pylori IgG test between July 2012 to June 2013. The patients were subdivided into: H. pylori infected children (GI), and H. pylori non-infected children (GII). Also, 320 of their family members were examined for serum anti-H. pylori IgG and stool antigen tests. Sheets were filled out included personal and medical history. The results showed statistically significant difference between both groups as regard dyspepsia, anemia, and histopathological findings (chronic active gastritis, peptic ulcer, and duodenitis). Family members were subdivided into: those of H. pylori infected symptomatic children (165) and those of H. pylori non-infected symptomatic children (155). Anti-H. pylori IgG prevalence was significantly higher in relatives of GI than those of GII (69.1% vs. 29%; p<0.05). The seroprevalence of H.pylori infection in all family members was (49.7%). Mothers of GI showed the highest seroprevalence (39.5%) as compared to fathers and siblings (22.8%, & 37.7%, respectively). Relatives of GI with low socioeconomic status, and lived in rural area showed the highest seroprevalence (82.5%, & 78.1% respectively).

Differential effects of alprazolam and clonazepam on the immune system and blood vessels of non-stressed and stressed adult male albino rats.

Benzodiazepines belongs to one of the most commonly used anxiolytic and anticonvulsant drugs in the world. Full description of toxic effects on different organs is lacking for nearly all the current benzodiazepines. The aim of the current work was to study the immunologic and vascular changes induced by sub-chronic administration of alprazolam and clonazepam in non-stressed and stressed adult male albino rats. Forty-two adult male albino rats were divided into 6 groups (I): (Ia) Negative control rats, (Ib): Positive control rats received distilled water, (II): Stressed rats, (III): Non-stressed rats received daily oral dose of clonazepam (0.5 mg/kg), (IV): Stressed rats received daily oral dose of clonazepam (0.5 mg/kg), (V): Non-stressed rats received daily oral dose of alprazolam (0.3 mg/kg). (VI): Stressed rats received daily oral dose of alprazolam (0.3 mg/kg). At the end of the 4th week, total leukocyte count (WBCs) and differential count were determined, anti-sheep RBC antibody (Anti-SRBC) titer and interleukin-2 (IL-2) level were assessed, thymus glands, lymph nodes, spleens and abdominal aortae were submitted to histopathological examination. Alprazolam was found to induce a significant increase in neutrophil count and a significant decrease in lymphocytes, anti-SRBC titer and IL-2 level with severe depletion of the splenic, thymal and nodal lymphocytes, accompanied by congestion and eosinophilic vasculitis of all organs tested in comparison to clonazepam treated rats. Stress enhanced the toxic effects. It was concluded that the immune system and blood vessels can be adversely affected to a greater extent by short-term chronic administration of alprazolam than by clonazepam, and these toxic effects are aggravated by stress.