Brainstem encephalitis (BE) associated with Mycoplasma pneumoniae in adults is rare, and the diagnosis is challenging. We describe an uncommon case of BE in an immunocompetent patient. A 43-year-old, otherwise healthy woman visited our emergency department with high fever and a sore throat, and 3 days later she returned with an altered drowsy mental status. Magnetic resonance imaging displayed diffuse swelling in bilateral cerebral regions involving the bilateral pons. The sera tested positive for the immunoglobulin (Ig) M antibody against M. Pneumoniae as detected by an enzyme immunoassay (EIA), and on hospital day 10, the level of IgM index against M. pneumoniae further increased from 1.5 to 2.1. We changed the antibiotic regimen from vancomycin and ceftriaxone to clarithromycin based on detection of M. pneumoniae, and we added intravenous immunoglobulin. After one month, the patient fully recovered from the neurological deficits. A follow-up brain magnetic resonance imaging was performed, which showed completely resolved lesions. Particle agglutination assay (PA) and EIA are both largely used to diagnose M. pneumoniae. Compared to the PA test, the EIA test could be a reliable tool because it separately measures IgM and IgG antibodies. We diagnosed BE associated with M. pneumoniae through EIA with an increasing level of IgM in the acute and subacute paired sera. Early treatment with macrolide antibiotics resulted in a good outcome.

At present, the only reliable test for COVID-19 diagnosis is RT-qPCR. Serological assays have been widely used to increase the detection sensitivity of infected population. Hereby, we report the performance of a new pan-IgG multiplex Enzyme Immunoassay (immunodot) method for exploration of discrepant SARS-COV-2 serological results.
A retrospective study on 38 residual serum samples from recovered COVID-19 subjects with discordant serological results on Roche and Snibe platforms, were reanalyzed on a new semi-automated pan-IgG immunodot Enzyme Immunoassay, namely COVIDOT-TEST, in order to find the source of discrepancies and to evaluate the latter method. All samples were analyzed on the BlueDiver® Instrument and all strips were read by the BlueScan® Scanner using Dr DOT® Software.
Based on our data, subject samples showed specific IgG reactions on ≥  2 different antigens on immunodot strips. Of these 38 samples, 97.4 % of samples showed specific IgG reaction against S1 + S2 antigens, 89.5 % showed against RBD antigen, 86.8 % against S2 antigen reaction on the COVIDOT-TEST kit. Specific IgG-S1 antigen and IgG-N antigen reactions were detected in 73.7 % and 65.8 % of the samples, respectively.
The new semi-automated pan-IgG immunodot Enzyme Immunoassay method appeared to be a reliable assay to confirm suspicious COVID-19 serological screening results.

BACKGROUND Few cases of falsely undetectable PSA due to the presence of an inhibitory serum factor have been reported in the world literature. We present a case of falsely low-to-undetectable PSA with data from a serum dilution series, the current literature on biochemical assay interference, and the implications for prostate cancer salvage treatment. CASE REPORT A 63-year-old man was treated with prostatectomy for high-risk prostate cancer and was found to have a rising PSA after approximately 3 years following surgery. He subsequently transferred his care to a different health system and was found to have an undetectable PSA. He was eventually found to have an elevated PSA once again after the particular assay at this institution was changed. He thus received salvage prostate radiotherapy and androgen deprivation therapy. CONCLUSIONS While falsely low PSA results cannot be explained by the presence of serum heterophile antibodies, competitive antibody interference against the immunoassay reagents or anti-PSA antibodies are possible explanations for the results of the dilution experiments performed in this case study. We suggest that unexpected PSA testing results should raise concern for assay interference and warrant further clinical workup.

BACKGROUND: Clostridioides (formerly Clostridium) difficile infection (CDI) is linked to misuse of antimicrobials. The prevalence of disease varies with difficulties of establishing the diagnosis because of the lack of sensitivity and specificity of laboratory tests. The clinical impact of upgrading CDI testing from routine to molecular based-algorithm is still unclear. The aim of this study is to assess the impact of upgrading CDI testing from routine to molecular based-algorithm on the management of CDI and evaluate the role of antimicrobials on the course of CDI.
METHODS: This is an observational case-study. A total of 564 patients were included from whom stool samples were tested by enzyme immunoassay (EIA) and Xpert for C. difficile. Data on the number and results of tests ordered, antimicrobial exposure, comorbidities, and treatment with metronidazole or vancomycin were collected. The main outcome measures were C. difficile tests (EIA and Xpert C. difficile Assay) and prevalence of CDI.
RESULTS: CDI was found in 9 and 10 cases out of 313 and 254 patients tested by the EIA and Xpert C. difficile assay, respectively, giving an overall incidence of 0.03 per 1,000 patient tested. Reduction was noted in the number of tests ordered per patient for presumptive CDI after shifting to the Xpert C. difficile assay which was not statistically significant (p-value 0.2). Also, there was less metronidazole and vancomycin therapy initiated for patients with a negative C. difficile test (p-value 0.2) observed with molecular testing.
CONCLUSIONS: Xpert C. difficile testing is a supportive tool for diagnosing CDI with rapid turnaround time that is helpful for patient management and initiating effective infection control measures. The clinical accuracy of the assay is still to be determined in the context of low carriage rate in the local patient population.

Adenoid hypertrophy (AH) is a common disease in children. We describe two cases of AH in children with syphilis enzyme-linked immunosorbent assay (EIA) for false-positive. To our knowledge, there are few reports of false-positive in syphilis EIA in children with AH. Two cases of AH children with syphilis EIA positive samples were confirmed by TPPA and LIA, both showed negative reaction. Therefore, the occurrence of syphilis EIA positive reactions in such diseases should dramatically arouse the attention of docimasters and doctors so as to avoid misdiagnosis caused by false-positive in children with AH.

BACKGROUND: To evaluate the ophthalmic manifestations and radiographic features of ectopic orbital meningioma to improve diagnostic accuracy.
METHODS: Patient data from patients admitted to our institution during a 217-month period from August 1999 to September 2017 were included. Patient ophthalmic manifestations, radiographic features (CT and MRI), diagnosis, pathology, therapeutic regimens, and prognosis were retrospectively reviewed.
RESULTS: Six patients with ectopic orbital meningioma were identified. The mean age at the first visit was 33.2 years (range, 7-56 years). All six patients displayed manifestations of exophthalmos, upper eyelid oedema, and motility impairment with a mean history of illness of 20.3 months (range 3-72 months). Optical lesions were located in the superonasal extraconal compartment (3/6, 50%), bitemporal extraconal compartment (1/6, 16.7%) and orbital intraconal compartment (2/6, 33%). Radiographic features were ill-defined, heterogeneous, enhancing soft tissue masses with extraocular muscular adhesion (6/6, 100%) and calcification (1/6, 16.7%), not adjacent to the optic nerve and not extending along the dura. Six cases were treated intraoperatively with complete surgical resection, indicating that all lesions were independent of the optic nerve and sphenoid ridge. The histopathologic classification was mostly of meningothelial cells (5/6, 83%). Immunohistochemistry revealed EMA and vimentin to have positive expression in all six cases, while two cases were calponin-positive and strongly expressed in the olfactory bulb. Postoperatively, lesions caused no visual impairment, and there were no cases of recurrence.
CONCLUSIONS: Ectopic orbital meningiomas are rare tumours that are not easily diagnosed without postoperative histopathology. This report highlights some of the distinguishing features of isolated orbital lesions, especially around the location of frontoethmoidal suture. Accompanying upper eyelid oedema and eye mobility restriction were observed to be dissimilar to other orbital tumours. In these cases, a diagnosis of ectopic orbital meningioma should be considered.

BACKGROUND: Pulmonary sequestration (PS) is a congenital pulmonary malformation wherein a piece of tissue that ultimately develops into lung tissue is not attached to the pulmonary arterial blood supply, sometimes it is difficult to diagnosis with no specific laboratory tests, discover an abnormal blood supply from aorta by imaging tests is a key step in diagnose.
METHODS: A 54-year-old male smoker presented with cough, expectoration and blood in the sputum.
METHODS: Computed tomography (CT) shows lesion in right lung, moderate standard uptake value (SUV) elevation of position-emission tomography/computed tomography (PET/CT) in a part of the lesion, and an increased (1,3)-β-D-glucan assay (G test), Galactomannan enzyme immune-assay (GM test) and tumor marker level, biopsy of lung in different times produced inconclusive results, then finally diagnose of pulmonary sequestration is made by observing an abnormal blood supply from the thoracic aorta and volume change of mass.
METHODS: The patient refused lower lobectomy which is the main treatment of PS. He was discharged with oral hemostatic and was advised to undergo regular medical checkups.
RESULTS: The patient has been followed for a year under an outpatient regimen. Symptoms of the cough and expectoration were relieved, however, blood in the sputum remains unchanged.
CONCLUSIONS: It suggests the need for criteria for a thorough diagnostic work-up. It put emphasis on the importance of considering PS as part of the diagnosis of a lesion in the lung disease and underscore the blood supply of mass. Bronchoscopy or pulmonary lobectomy and follow up of the patient are important for patients diagnosed with pulmonary sequestration.

Estimation of the effectiveness of rotavirus vaccines via the test-negative control study design has gained popularity over the past few years. In this study design, children with severe diarrhea who test positive for rotavirus infection are considered as cases, while children who test negative serve as controls. We use a simple probability model to evaluate and compare the test-negative control and the traditional case-control designs with respect to the bias of resulting estimates of rotavirus vaccine effectiveness (VE). Comparisons are performed under two scenarios, corresponding to studies performed in high-income and low-income countries. We consider two potential sources of bias: (a) misclassification bias resulting from imperfect sensitivity and specificity of the test used to diagnose rotavirus infection, and (b) selection bias associated with possible effect of rotavirus vaccination on the probability of contracting severe non-rotavirus diarrhea. Our results suggest that both sources of bias may produce VE estimates with substantial bias. Particularly, lack of perfect specificity is associated with severe negative bias. For example, if the specificity of the diagnostic test is 90% then VE estimates from both types of case-control studies may under-estimate the true VE by more than 20%. If the vaccine protects children against non-rotavirus diarrhea then VE estimates from test-negative control studies may be close to zero even though the true VE is 50%. However, the sensitivity and specificity of the enzyme immunoassay test currently used to diagnose rotavirus infections are both over 99%, and there is no solid evidence that the existing rotavirus vaccines affect the rates of non-rotavirus diarrhea. We therefore conclude that the test-negative control study design is a convenient and reliable alternative for estimation of rotavirus VE.

Blastomyces dermatitidis is a thermally dimorphic fungus that is capable of causing pulmonary and extra-pulmonary disease, including infections of the central nervous system (CNS). Diagnosis of CNS blastomycosis with non-invasive testing can be difficult, and a surgical biopsy may ultimately be required for microbiological and/or histopathological confirmation. A case of B. dermatitidis meningitis is presented where the diagnosis was made by testing cerebrospinal fluid (CSF) using the MVista® Blastomyces Quantitative Antigen Enzyme Immunoassay test. The utility of performing this test on CSF for diagnosis of CNS mass lesions/abscesses caused by B. dermatitidis in the absence of associated meningitis remains unclear. Cross reaction of the Blastomyces antigen test with other dimorphic fungi is a concern, necessitating that positive test results are interpreted in the context of the patient\'s exposure and travel history.

BACKGROUND: Ethyl glucuronide (EtG) in urine is considered a marker of recent ethanol consumption or ethanol exposition. tert-Butanol is primarily used as a solvent and intermediate chemical. Like tert-amyl alcohol, tert-butanol is discussed in Internet forums as ethanol replacement. We discuss false-positive immunological EtG screenings by excretion of different alcohol glucuronides (EtG homologs), mainly tert-butyl glucuronide in urine of a polytoxikomanic in-patient.
METHODS: Three consecutive urine samples from an in-patient with a long history of multiple substance abuse including solvents were analyzed by DRI EtG enzyme immunoassay (ThermoFisher Scientific Microgenics) on a Beckman Coulter AU680 analyzer, an in-house LC-MS/MS for EtG, 1-propyl, 2-propyl, 1-butyl, 2-butyl, and tert-butyl glucuronide, and an in-house headspace GC-FID of free congener substances methanol, 1-propanol, 2-butanone, 2-butanol, isobutanol, 1-butanol, 3-methyl-1-butanol, 2-methyl-1-butanol, and additionally for ethanol, acetone, 2-propanol, tert-butanol and 2-methyl-2-butanol.
RESULTS: EtG immunoassay yielded two positive urine samples (0.2 and 0.6mg/L or 0.1 and 0.2mg/g creatinine; cut-off 0.1mg/L) which were tested EtG negative by LC-MS/MS (cut-off 0.1mg/L) but positive for tert-butyl glucuronide (3.7 and 27.1mg/L), 2-butyl glucuronide (1.1 and 3.5mg/L), and 2-propyl glucuronide (0.1 and 0.4mg/L). Headspace GC-FID detected tert-butanol (0.97 and 4.01mg/L), methanol (0.96 and 0.62mg/L), 2-butanone (0.84 and 1.65mg/L), and 2-butanol (0.04 and 0.09mg/L), but no ethanol and no 2-methyl-2-butanol.
CONCLUSIONS: Cross-reaction of EtG homologs, mainly tert-butyl glucuronide after suspected tert-butanol or isobutane abuse, explains the false-positive EtG immunoassay findings. Future investigations could address the usefulness of alcohol glucuronides (EtG homologs) in urine as (a) biomarkers of an exposition to alkans or their corresponding alcohol metabolites and (b) as markers for using \"old\"-well known alcohols like tert-butanol or tert-amyl alcohol as easy to obtain, cheap, potent and \"undetectable\" ethanol replacements or \"New\" Psychoactive Alcohols.