Correlation of SARS-CoV2 Viral Growth on Cultures, Ct Values, SARS-CoV-2 Variant and Vaccination Status in Asymptomatic, Pre-Symptomatic and Post-Infection Asymptomatic COVID Patients

Introduction/Objective

COVID-19 large scale immunizations have helped control the infectious spread, but breakthrough infections are still observed and some of these patients remain asymptomatic. In this study, we compared the viral growth characteristics with vaccination status in asymptomatic patients.

Methods/Case Report

We searched our institutional laboratory database for asymptomatic patients infected with delta variant (November-December 2021, n=65) and omicron variant (December 2021, n=68), that were further classified as “truly asymptomatic”, “pre-symptomatic” and “post-infection asymptomatic” based on detailed chart reviews. The patients’ left-over nasopharyngeal swab samples’ cycle threshold values and the recovery of infectious virus in cell culture were compared.

Results (if a Case Study enter NA)

In the delta cohort, out of 65 asymptomatic patients, 36 were truly asymptomatic, 26 presymptomatic and 3 post infection asymptomatic patients. In the omicron cohort, out of 68 asymptomatic patients, 45 were truly asymptomatic and 23 were presymptomatic patients. The vaccination rate was 59% in truly asymptomatic (delta cohort=56%, omicron cohort=62%), 55% in presymptomatic (delta cohort=50%, omicron cohort=61%) and 67% in post-infection patients (delta cohort only). There was no significant difference in the Ct values of truly asymptomatic (mean Ct=21.08), presymptomatic (mean Ct=20.30) and post-infection asymptomatic patients (mean Ct=20.84) in the combined cohort (p=0.78) and in the delta (p=0.95) or omicron (p=0.45) subcohorts. The Ct values were not correlated with the vaccination status of the patients (vaccinated patients mean Ct=20.56, non-vaccinated patients mean Ct=20.16, p=0.68). Samples with positive viral growth on cultures had significantly lower Ct values (mean Ct= 17.16), compared to samples with negative viral culture results (mean Ct= 24.61) (p<0.0001). The viral growth on culture was not associated with the symptom status, SARS-CoV-2 variant type (delta vs omicron) and vaccination status of the patients in the delta and omicron subcohorts.

Conclusion

Our findings show that there is no significant correlation between vaccination status and viral loads and culture results in asymptomatic patients.

P258 Pharmacometabolomics analysis of plasma and urine to identify clopidogrel exposure metabolic biomarkers

Funding Acknowledgements

This research was funded by Universiti Sains Malaysia

Introduction

Clopidogrel is a widely used P2Y12 antiplatelet drug. Patient"s compliance to clopidogrel is crucial to achieve therapeutic outcome and prevent thromboembolic events. While measuring serum level of clopidogrel and/or its active metabolite may indicate compliance, many confounding factors interfere, however, often compromising the reliability of the results. Identifying drug exposure metabolic biomarkers is reliable and fast tool to evaluate patient"s compliance, as well as getting in-depth information on the metabolic perturbation associated with drug exposure. We hypothesized that Nuclear magnetic resonance (1HNMR) pharmacometabolomics analysis of plasma and urine can phenotype clopidogrel loading dose (LD) in coronary artery disease (CAD) patients.

Purpose

We aimed to phenotype clopidogrel exposure in plasma and urine of CAD patients using 1HNMR pharmacometabolomics. 

Methods

We analysed pre-dose and post-dose plasma and urine samples from 79 CAD patients who had clopidogrel 600 mg LD using 1HNMR pharmacometabolomics technique. Data analysis of 1HNMR spectra was performed by developing preliminary orthogonal partial least square discriminant analysis models (OPLS-DA). This was followed by univariate logistic regression (ULR), factor analysis (FA) and multivariate logistic regression (MVLR) for the 1HNMR spectral regions with variable influence on projection (VIP) > 1 in the OPLS-DA preliminary models to indicate the best discriminating models (metabotypes). Area under receiver operating characteristic (AUROC) was used to evaluate the OPLS-DA and MVLR models. 

Results

OPLS-DA models discriminated between pre-dose and post-dose in plasma and urine with accuracy of 91.77% and 100%, respectively. MVLR indicated final plasma and urine metabotypes with accuracy of 84.2% and 82.2%, respectively. From the final exposure metabotypes, 27 and 20 metabolites were found perturbed in plasma and urine upon exposure to clopidogrel LD, respectively.

Conclusion

1HNMR pharmacometabolomics analysis of plasma and urine was efficient in phenotyping clopidogrel exposure with good accuracy. The study is ongoing to indicate metabolic pathways associated with clopidogrel exposure.

Models Accuracy Metabotype OPLS-DA Model MVLR Model Specificity Sensitivity Accuracy AUROC Specificity Sensitivity Accuracy AUROC Plasma 96.20% 87.34% 91.77% 0.99 97.5% 70.9% 84.2% 0.88 Urine 100% 100% 100% 1.0 93.2% 71.2% 82.2% 0.924 OPLS-DA: orthogonal partial least square discriminant analysis, MVLR: multivariate logistic regression, AUROC: Area under receiver operating characteristic

The ASOS Surgical Risk Calculator: development and validation of a tool for identifying African surgical patients at risk of severe postoperative complications

BACKGROUND

The African Surgical Outcomes Study (ASOS) showed that surgical patients in Africa have a mortality twice the global average. Existing risk assessment tools are not valid for use in this population because the pattern of risk for poor outcomes differs from high-income countries. The objective of this study was to derive and validate a simple, preoperative risk stratification tool to identify African surgical patients at risk for in-hospital postoperative mortality and severe complications.

METHODS

ASOS was a 7-day prospective cohort study of adult patients undergoing surgery in Africa. The ASOS Surgical Risk Calculator was constructed with a multivariable logistic regression model for the outcome of in-hospital mortality and severe postoperative complications. The following preoperative risk factors were entered into the model; age, sex, smoking status, ASA physical status, preoperative chronic comorbid conditions, indication for surgery, urgency, severity, and type of surgery.

RESULTS

The model was derived from 8799 patients from 168 African hospitals. The composite outcome of severe postoperative complications and death occurred in 423/8799 (4.8%) patients. The ASOS Surgical Risk Calculator includes the following risk factors: age, ASA physical status, indication for surgery, urgency, severity, and type of surgery. The model showed good discrimination with an area under the receiver operating characteristic curve of 0.805 and good calibration with c-statistic corrected for optimism of 0.784.

CONCLUSIONS

This simple preoperative risk calculator could be used to identify high-risk surgical patients in African hospitals and facilitate increased postoperative surveillance.

CLINICAL TRIAL REGISTRATION

NCT03044899.

Thyroid hormones and thyroid-stimulating hormone in Egyptian patients with systemic lupus erythematosus: correlation between secondary hypothyroidism and neuropsychiatric systemic lupus erythematosus syndromes

Abstract The purpose of this study was to determine the serum levels of thyroid hormones and thyroid-stimulating hormone (TSH), in addition to antithyroglobulin and antimicrosomal antibodies and to investigate the correlation between these hormones and various disease manifestations among Egyptian patients with systemic lupus erythematosus (SLE). A group of 45 patients with SLE (43 women and 2 men with a mean age of 27.57 ± 9.89 years) underment assessment of their thyroid hormones. Antithyroglobulin and antimicrosomal antibodies were assessed in 27 patients. Various disease manifestations were evaluated. A group of 20 normal female volunteers were involved as controls. The mean serum free triiodothyronine (FT3) levels in all patients were significantly lower than in controls (1.89 ± 1.14 vs. 3.15 ± 0.93 pg/ml; P < 0.05). Patients with a history of intravenous pulsed cyclophosphamide therapy showed significantly decreased levels of FT3 compared to those in other patients (1.17 ± 0.5 vs. 2.05 ± 0.95 pg/ml; P = 0.04). The mean serum free thyroxine (FT4) levels in all patients were significantly less than in the control group (1.24 ± 1.22 vs. 1.4 ± 0.3 mg/dl; P < 0.001). Of the 45 patients, 2 (4.4%) were considered to have primary hypothyroidism. Five of six patients (83.3%) with decreased FT4 levels developed fibromyalgia compared to 7 of 39 (17.9%) patients with normal T4 (P = 0.003). The mean serum TSH levels in all patients were significantly higher than in the controls (4.82 ± 22.2 vs. 2.65 ± 1.18 μIU/ml; P < 0.001). Six patients with decreased TSH levels were considered to have secondary hypothyroidism (13.3%); one of them showed decreased T3 and T4, two had decreased T4 only, and the other three were euthyroid. Comparing patients with and without secondary hypothyroidism, showed acute confusion in four (66.7%) in the former group versus four (10.3%) in the latter group (P = 0.006), anxiety in four (66.7%) in the former group versus six (15.4%) in the latter group (P = 0.016), and cognitive disorders in five (83.3%) in the former group versus nine (23.1%) in the latter group (P = 0.008). This study demonstrated evidence of secondary as well as primary hypothyroidism in SLE patients and revealed a close association between thyroid hormones or TSH and some organ involvement in SLE.

Symptomatic thrombotic events among Egyptian patients with systemic lupus erythematosus: special consideration for renal vein thrombosis

OBJECTIVE

To evaluate the prevalence of symptomatic thrombotic events among Egyptian patients with systemic lupus erythematosus (SLE), and to evaluate the frequency and the risk factors associated with renal vein thrombosis in those patients.

METHODS

Fifty-four patients with SLE, 51 (94.4%) females, were involved in this study. All of them were submitted for abdominal sonography, chest X-ray, echocardiography, and Doppler of renal, abdominal and lower limb veins, with examination of data on clinical and laboratory profile. Abdominal CT, brain MRI, MRI both hips, CT chest and pulmonary scintigraphy were used when needed.

RESULTS

Sixteen patients (29.6%) were diagnosed with symptomatic thrombotic events. Eight patients had more than one type of thrombosis. Two patients (3.7%) were diagnosed by Doppler as having renal vein thrombosis (RVT). This was confirmed by abdominal CT. One of them presented with nephrotic syndrome, graded by renal biopsy as World Health Organization (WHO) class V, and had positive anticardiolipin antibodies (ACL). The other patient had RVT and inferior vena cava (IVC) thrombosis, nephrotic syndrome, positive ACL, and died before renal biopsy was performed. Both of them were without history of peripheral thrombotic events. One patient was diagnosed with IVC thrombosis, lupus nephritis grade II, positive ACL, and diagnosed by abdominal CT. One patient was diagnosed with portal vein thrombosis and had positive ACL. One patient with retinal vessel thrombosis and positive ACL. Four patients had deep vein thrombosis (DVT). Recurrent miscarriages were reported in 4 patients (7.4%), skin ulcerations in 3 (5.6%), avascular necrosis of the hips in 4 (7.4%), stroke in 1 (1.9%), and pulmonary hypertension in 2 patients (3.7%).

CONCLUSION

Sixteen SLE patients (29.6%) were diagnosed with symptomatic thrombotic events. RVT was detected in 2 patients representing 3.7% of all patients, and 12.5% of patients with thrombosis. Both patients with RVT presented with nephrotic syndrome.

Plasma endothelin-1 concentrations in children with cirrhosis and their relationship to renal function and the severity of portal hypertension

BACKGROUND

Plasma endothelin-1 (ET-1) is a potent vasoconstrictor peptide involved in the pathogenesis of several disorders. Endothelin-1 concentrations are increased in adult patients with cirrhosis. However, little is known about ET-1 concentrations in children with cirrhosis.

METHODS

Radioimmune assay was used to measure plasma ET-1 concentrations in 19 children with cirrhosis (8 patients with ascites, and 11 without ascites), and 11 age- and sex-matched healthy children. The plasma ET-1 concentrations were correlated with the mean blood pressure, creatinine clearance, and severity of portal hypertension, as measured by portal flow volume and portal flow velocity.

RESULTS

Patients with cirrhosis and ascites had increased plasma ET-1 concentrations compared with patients who did not have ascites (6.8 pg/mL +/- 0.62 pg/mL vs. 4.6 pg/mL +/- 0.35 pg/mL; mean +/- SEM; < 0.01) and controls (3.6 pg/mL +/- 0.27 pg/mL; mean +/- SEM; < 0.0005). Plasma ET-1 concentrations were higher in patients with cirrhosis who did not have ascites compared with controls ( < 0.005). No significant differences were observed between concentrations of the patients with cholestasis and those without cholestasis (5.4 pg/mL +/- 0.52 pg/mL vs. 5.2 +/- 0.32 pg/mL; mean +/- SEM; = 0.1). Plasma ET-1 concentrations correlated positively with the mean blood pressure ( = 0.58; < 0.05) and negatively with renal function, as measured by creatinine clearance ( = -0.7; <0.005). However, no correlation was detected between ET-1 concentrations and portal flow volume ( = -0.02; = 0.4) or portal flow velocity ( = -0.16; = 0.4).

CONCLUSIONS

Plasma ET-1 concentrations are increased in children with cirrhosis, with or without ascites, compared with controls. Patients with cirrhosis and ascites have increased ET-1 concentrations compared with those without ascites. The degree of increase does not relate to the severity of portal hypertension. This increase tends to maintain systemic blood pressure but is associated with a decrease in renal function.

Evaluation of the triangular cord sign in the diagnosis of biliary atresia

BACKGROUND

Infantile cholestasis continues to represent a diagnostic challenge. It is very important to diagnose surgically correctable disorders, such as biliary atresia, in a timely manner to prevent progressive damage to the liver. It has been recently suggested that the triangular cord (TC) sign is a simple and useful tool in the diagnosis of biliary atresia.

METHODS

We prospectively studied 65 infants presenting with conjugated hyperbilirubinemia (age range: 32-161 days). All patients underwent ultrasonographic examination with a 7.0-MHz transducer (Acuson, Mountain View, CA). The TC was defined as a triangular, or tubular, echogenic density seen immediately cranial to the portal vein bifurcation.

RESULTS

The TC sign was identified in 25 infants, and all of them had histologic features suggestive of biliary atresia; the diagnosis was confirmed at surgery by gross morphology of hepatobiliary system, and liver biopsy, with or without intraoperative cholangiogram. Among the 40 patients who did not have the TC sign, 6 had paucity of the intrahepatic bile ducts. Three had alph-1-antitrypsin deficiency, and 31 had neonatal hepatitis. None of the 40 patients who did not have the TC sign developed acholic stools. Seven patients with biliary atresia were followed by ultrasonographic examination for 6 months after the Kasai procedure. The TC sign disappeared in all patients after the surgery; however, the TC sign reappeared in 3 patients who developed progressive cholestasis after the procedure.

CONCLUSION

The TC sign is a simple, timesaving, and reliable diagnostic tool in the evaluation of infants with infantile cholestasis. The TC sign may also prove to be helpful in following patients after hepatoportoenterostomy. We suggest a new diagnostic strategy for patients suspected to have biliary atresia. When the TC sign is visualized, the patient should undergo intraoperative cholangiogram to confirm the diagnosis of biliary atresia, reserving percutaneous liver biopsy for those patients in whom the TC sign could not be detected.

Endoscopic management of ejaculatory duct obstruction

A total of 191 patients were evaluated at our department for azoospermia, and 11 were found to have azoospermia due to ejaculatory duct obstruction as proved by normal serum hormones, normal testicular biopsy, low ejaculate volume and absence of fructose in semen. Also transrectal ultrasound was performed, revealing distended seminal vesicles and dilated ejaculatory ducts. All these criteria together suggested ejaculatory duct obstruction as a cause of azoospermia. All patients underwent endoscopic management for treatment of their ejaculatory duct obstruction in the form of resection and/or incision of the ejaculatory duct ostium inside the urethra and patency was checked intraoperatively by injection of sterile methylene blue in the vas and visualizing the efflux of the blue dye endoscopically. Intraoperative patency was documented in 10 patients and postoperative patency by follow-up semen analysis in 7 patients (70% patency rate) of which 2 (20% pregnancy rate) were able to conceive within 2 years of endoscopic treatment. Postoperative complications included acute urinary retention in 1 patient, haematuria in 5 and recurrent epididymitis in 2 patients.

Evaluation of the role of corpus cavernosum electromyography as a noninvasive diagnostic tool in male erectile dysfunction

Corpus cavernosum electromyography (EMG) and its evolution: single potential analysis of cavernous electrical activity (SPACE) seem to be promising diagnostic methods in the evaluation of erectile dysfunction and smooth muscle integrity. Our study concentrates on the role of EMG in the evaluation of corpus cavernosum smooth muscles, using it as a noninvasive technique for demonstrating autonomic erectile dysfunction through their influence on recording SPACE and consequent proper selection of patients for different therapeutic modalities. A total of 80 male patients were examined for the feasibility of transcutaneous registration of cavernous electrical activity with a 2-channel electrophysiological unit (Evamatic 2000, Dantec) with two surface electrodes bilaterally placed on the penile shaft. Ten patients had normal erectile function, but complained of other urological symptoms. They served as the controls for normal electrical activity. Fifty patients with organic impotence of nonvascular (neurogenic) or vascular (venogenic, arteriogenic) aetiologies were subjected to EMG in both the flaccid and the erect state. On the basis of the EMG patterns the patients were divided into the following groups: 34 patients having normal tracing in both the flaccid and the erect state, and 21 patients showing abnormal patterns of waves with evidence of autonomic neurogenic dysfunction and incomplete smooth muscle relaxation. Of the latter 4 had long-standing diabetes mellitus and 4 had spinal injuries.

Study of the arterial pattern of the rectum and its clinical application

The purpose of this communication was to study rectal arterial supply in order to characterize its various patterns and use them to help avoid rectal ischemic complications and, in addition, to explain some of the unknown rectal pathologic conditions. Thirty-two cadavers were studied. The pelvic organs were eviscerated. The rectal arteries were examined by direct dissection in 12 specimens and after injecting the inferior mesenteric artery with barium sulfate in 20 specimens. The superior rectal artery (SRA) and vein were found to be enclosed in a fibrous sheath which was connected to the posterior rectal surface by an anterior mesorectum containing the "transverse rectal branches', and to the sacrum by an avascular posterior mesorectum. Small lymph nodes were scattered alongside the anterior mesorectum. The SRA gave rise to 4 branches: transverse rectal, descending rectal, rectosigmoid and terminal. The transverse rectal arteries arose from the SRA in 24 specimens and from the descending rectal artery in 8. They were distributed to the upper half of the rectum. The rectosigmoid artery was distributed to the descending limb of the sigmoid colon and rectosigmoid junction. We found 2 terminal branches in 21/32 cadavers and 3 in 11/32. They communicated in the lower half of the rectum. The inferior rectal arteries were present in all the dissected cadavers while the middle rectal arteries could be identified in only 50% of the cadavers. Two arterial patterns were recognized: annular in the upper rectal half provided by the transverse rectal arteries and plexiform in the lower half supplied by the SRA terminal branches.

Serum levels of tumor necrosis factor in different stages of schistosomal infection

Schistosomal infections present their hosts with enormous immunological problems. The cytokine tumor necrosis factor, an effector molecule released mainly by stimulated macrophages is involved in various defence mechanisms mounted by the host against schistosome, However, TNF can be dangerous and may contribute to the pathology associated with schistosmal infections. In this study, the authors examined the circulating levels of TNF, IgE and the eosinophilic count in 41 patients and 25 health controls, trying to find an association between TNF concentrations and severity of the disease, IgE levels and eosinophilic count. All cases had significant anaemia, eosinophilia, elevated IgE and TNF concentrations.