scholarly journals Allergen-specific skin prick tests in allergist practice

2013 ◽  
Vol 10 (4) ◽  
pp. 44-53
Author(s):  
I S Gushchin ◽  
I V Danilycheva
Keyword(s):  
Skin Prick Testing ◽  
Skin Testing ◽  
False Negative ◽  
Specific Treatment ◽  
Diagnostic Methods ◽  
Clinical Value ◽  
Negative Results ◽  
False Negative Results ◽  
Allergenic Extracts ◽  
The Right

Identification of patient’s allergen-specific hypersensitivity and its clinical value is a basis of the right choice allergen-specific treatment. The problem is solved by an allergist with the use of different diagnostic methods. The most important stage of diagnostics is an allergen-specific skin testing more widely used as a skin prick testing (SPT). The paper concerns SPT technique, indications and contraindications for the testing, interpretations of SPT results, performance at certain groups of patients, the most probable mistakes in carrying out SPT, the reasons of false positive and false negative results, a comparative assessment of SPT and other methods of allergen-specific diagnostics, requirements to allergenic extracts.

scholarly journals Detection of LytA Genes in Streptococcus pneumoniae Isolated from sputum pneumonia patients

Biomedika ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 23-30
Author(s):  
Mustika Sari Hutabarat ◽  
Firdaus Hamid ◽  
Irawaty Djaharuddin ◽  
Alfian Zainuddin ◽  
Rossana Agus ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
False Negative ◽  
Pneumococcal Infection ◽  
Diagnostic Methods ◽  
Molecular Diagnostic ◽  
Clinical Samples ◽  
Biochemical Tests ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain

Streptococcus pneumoniae (pneumococcus) is a Gram-positive facultative anaerobic bacterium that is a major cause of morbidity and mortality worldwide. But the lack of reporting of disease by this bacterium in Indonesia, one of the causes is because the diagnosis of pneumococcal infection is often clinically not typical and conventional methods which are still the standard gold method often give false-negative results. So the purpose of this study was to evaluate the performance of culture and molecular diagnostic methods using the Polymerase Chain Reaction (PCR) technique in detecting Streptococcus pneumoniae in sputum clinical samples using the Autolysin (LytA) gene which is a virulence factor of this bacterium. 57 isolates from 60 samples were confirmed as Streptococcus sp through microscopic identification, culture, and biochemical tests. Then the sensitivity test with an optochin test of 9 (9%) compared the results descriptively with the PCR technique using the Autolysin A (LytA) gene which was obtained more sensitive by 15 (25%).

S235 – Diagnostic Test Validation: CHAMP in Endolymphatic Hydrops

2008 ◽  
Vol 139 (2_suppl) ◽  
pp. P154-P154
Author(s):  
Eveling Y Rojas ◽  
Leonardo Ordoñez ◽  
Victor Hernandez ◽  
Jose E Guzman ◽  
Juan Izquierdo ◽  
...  
Keyword(s):  
Diagnostic Test ◽  
Endolymphatic Hydrops ◽  
False Negative ◽  
High Specificity ◽  
Diagnostic Value ◽  
Clinical Value ◽  
Negative Results ◽  
False Negative Results ◽  
The Relationship

Objectives The Cochlear Hydrops Analysis Masking Procedure (CHAMP) has been reported with a high sensibility and specificity for the diagnosis of endolymphatic hydrops (ELH). Nevertheless, a complete validation of CHAMP with precise methods has not been done. Our objectives: To determine whether CHAMP has a diagnostic value in patients with definite, probable/possible diagnosis of Meniere's disease or endolymphatic hydrops, based on the criteria of the AAO-HNS. Methods Prospective validation study for a diagnostic test: phase II. Latency of wave V was assessed using CHAMP. We classified subjects in 5 groups: 1-Definite ELH, 2-Probable ELH, 3-Possible ELH, 4-subjects with other otovestibular symptoms, 5-normal hearing subjects. We included cases (groups 1–4) with an episode of vertigo with duration equal or longer than 20 minutes, with or without other otovestibular symptoms. Results We included 67 cases (132 ears). 38 cases (76 ears) completed the follow up and their results are presented. In group 1, the sensibility of CHAMP was 43% and its specificity was 100%. In groups 2–3, the sensitivity was 20% and the specificity 100%, with 0% false positive and 80% false negative results. Other indicators of validity for this diagnostic test are presented. Conclusions CHAMP has a high specificity and low sensibility for the diagnosis of ELH when the delay in wave V latency is used. Future studies may assess the relationship between wave amplitudes to improve the clinical value of CHAMP.

scholarly journals Evaluation of the Allplex™ GI-Helminth(I) Assay, the first marketed multiplex PCR for helminth diagnosis

Parasite ◽  
2021 ◽  
Vol 28 ◽  
pp. 33
Author(s):  
Brice Autier ◽  
Jean-Pierre Gangneux ◽  
Florence Robert-Gangneux
Keyword(s):  
Multiplex Pcr ◽  
False Negative ◽  
Extraction Process ◽  
Trichuris Trichiura ◽  
Diagnostic Methods ◽  
Bead Beating ◽  
Negative Results ◽  
Multiplex Pcr Assay ◽  
False Negative Results ◽  
Mechanical Lysis

Molecular biology has been gaining more importance in parasitology. Recently, a commercial multiplex PCR assay detecting helminths was marketed: the Allplex™ GI-Helminth(I) Assay. It targets Ancylostoma spp., Ascaris spp., Enterobius vermicularis, Hymenolepis spp., Necator americanus, Strongyloides spp., Taenia spp. and Trichuris trichiura, but also the two most common microsporidia genera in human health, i.e. Enterocytozoon spp. and Encephalitozoon spp. This study aimed to evaluate and compare the Allplex™ GI-Helminth(I) Assay to classical diagnostic methods, based on a cohort of 110 stool samples positive for helminths (microscopy) or for microsporidia (PCR). Samples were stored at −80 °C until analysis by the Allplex™ GI-Helminth(I) Assay. False-negatives were re-tested with bead-beating pretreatment. Without mechanical lysis, concordance and agreement between microscopy and Allplex™ GI-Helminth(I) Assay ranged from 91% to 100% and from 0.15 to 1.00, respectively depending on the target. Concordance was perfect for Taenia spp. (n = 5) and microsporidia (n = 10). False-negative results were observed in 54% (6/13), 34% (4/11) and 20% (7/35) of cases, for hookworms, E. vermicularis and Strongyloides spp. detection, respectively. For these targets, pretreatment improved the results, but only slightly. Trichuris trichiura detection was critically low without pretreatment, as only 9% (1/11) of the samples were positive, but detection reached 91% (10/11) with bead-beating pretreatment. Mechanical lysis was also needed for Ascaris spp. and Hymenolepis spp. to reduce false-negative results from 1/8 to 1/21, respectively, to none for both. Overall, with an optimized extraction process, the Allplex™ GI-Helminth(I) Assay allows the detection of numerous parasites with roughly equivalent performance to that of microscopy, except for hookworms.

Has the Nitroblue Tetrazolium Test Proved Itself?

PEDIATRICS ◽  
1972 ◽  
Vol 49 (2) ◽  
pp. 311-311
Author(s):  
Victor B. Abello
Keyword(s):  
False Positive ◽  
Bacterial Infections ◽  
False Negative ◽  
Nitroblue Tetrazolium ◽  
Clinical Value ◽  
Negative Results ◽  
False Negative Results ◽  
Nbt Test ◽  
Nbt Reduction ◽  
Nitroblue Tetrazolium Test

I followed with interest the use of the nitroblue tetrazolium (NBT) reduction test in the differential diagnosis of viral and bacterial infections.1-3 My enthusiasm, however, has been slowly dampened. With more work being done, there has been increasing awareness of the different false-positive and false-negative results.2-5 Consequently, I believe its clinical value is waning even before the test has been generally made available to practitioners. The NBT test will probably fall in the category of WBC and differential in its use in differentiating viral from bacterial infections, which similarly has numerous false-positive and false-negative results and has to be correlated clinically.

scholarly journals Diagnosis of COVID-19 by Serology in Admitted Patients with Negative RT-PCR Assay

2021 ◽  
Author(s):  
Mitra Rezaei ◽  
Parvaneh Baghaei ◽  
Makan Sadr ◽  
Afshin Moniri ◽  
Abdolreza Babamahmoodi ◽  
...  
Keyword(s):  
Diagnostic Yield ◽  
Serological Test ◽  
False Negative ◽  
Diagnostic Methods ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Serological Tests ◽  
Negative Results ◽  
False Negative Results ◽  
Polymerase Chain

Considering the increasing prevalence and burden of coronavirus disease 2019 (COVID-19) disease and false-negative results in routine reverse transcription-polymerase chain reaction (RT-PCR) tests, additional diagnostic methods are needed to diagnose active cases of this disease. This prospective study was conducted on patients, in whom clinical and radiological symptoms/signs were in favor of COVID-19 while their first PCR test was negative. Later on, a second RT-PCR was performed and serological evaluation was carried out and results were compared with each other. Out of 707 patients who had been referred to the hospital and were clinically and radiologically suspicious of disease, 137 patients with negative RT-PCR tests entered the study. RT-PCR assay became positive for the second time in 45 (32.8%). Anti-COVID-19 IgM and IgG antibodies were positive in 83 (60.6%) and 86 (62.8%) patients, respectively. Finally, it was determined that serological test was diagnostic in 73% of patients and the diagnostic yield of serology was significantly higher after the first week of illness (54.8% in the first week and 88% after that). Taking advantage of both serological tests and RT-PCR helps in diagnosing 83.9% of cases. Based on the present study, the serology may be useful as a complementary test and in parallel to RT-PCR assay for diagnosis of COVID-19 among admitted symptomatic cases.

Usefulness of β2-transferrin assay in the detection of cerebrospinal fluid leaks following head injury

1992 ◽  
Vol 77 (5) ◽  
pp. 737-739 ◽  
Author(s):  
Richard G. Ryali ◽  
Michael K. Peacock ◽  
Donald A. Simpson
Keyword(s):  
Cerebrospinal Fluid ◽  
Head Trauma ◽  
False Negative ◽  
Csf Leak ◽  
Clinical Value ◽  
Noninvasive Test ◽  
Content Type ◽  
Negative Results ◽  
False Negative Results ◽  
Csf Leakage

✓ The clinical value of analyzing various fluids and exudates for β2-transferrin (β2-Tfn) to detect cerebrospinal fluid (CSF) leakage following head trauma was reviewed in a series of 11 cases. Qualitative detection of β2-Tfn was performed by agarose gel electrophoresis of tears, ear and nose exudates, cerebral cyst fluid, and wound discharge fluid in different cases. In each instance the presence of β2-Tfn in the analyzed fluid supported the diagnosis of a CSF leak. Equally, the demonstration of the absence of β2-Tfn in the fluid excluded the diagnosis of such a leak. Neither false-positive nor false-negative results were found, as indicated by separate radiological investigations and/or subsequent clinical assessment of patients. The detection of β2-Tfn in suspect fluids thus provides a highly sensitive and selective, rapid, and noninvasive test for the detection of CSF leakage in cases of head trauma.

EUTETIC MIXTURE OF LOCAL ANESTHETICS (EMLA) CREAM FOR PAINLESS SKIN TESTING: A PRELIMINARY REPORT

PEDIATRICS ◽  
1995 ◽  
Vol 96 (2) ◽  
pp. 384-384
Author(s):  
Betty Miller
Keyword(s):  
Local Anesthetics ◽  
Preliminary Report ◽  
Skin Testing ◽  
False Negative ◽  
Efficacy And Safety ◽  
Intradermal Testing ◽  
Emla Cream ◽  
Negative Results ◽  
False Negative Results

This study confirms the anesthetic efficacy and safety of EMLA cream. The EMLA cream did not interfere with the formation of wheals and flares and therefore did not jeopardize the purpose of intradermal skin testing. The recommended 1-hour wait was best for effective anesthesia. EMLA is not recommended for infants less than 1 month or for infants under 1 year of age who are receiving sulfonamide or methemoglobin-inducing agents. Because this is only a preliminary report, larger numbers of children need to be evaluated for false negative results when EMLA is used in conjunction with intradermal testing.

Critical Evaluation of Impedance Phlebography for the Diagnosis of Deep Vein Thrombosis

1974 ◽  
Vol 31 (02) ◽  
pp. 273-278
Author(s):  
Kenneth K Wu ◽  
John C Hoak ◽  
Robert W Barnes ◽  
Stuart L Frankel
Keyword(s):  
Deep Vein Thrombosis ◽  
False Positive ◽  
False Negative ◽  
Critical Evaluation ◽  
Original Method ◽  
Vein Thrombosis ◽  
Negative Results ◽  
False Negative Results ◽  
Deep Vein ◽  
Positive Results

SummaryIn order to evaluate its daily variability and reliability, impedance phlebography was performed daily or on alternate days on 61 patients with deep vein thrombosis, of whom 47 also had 125I-fibrinogen uptake tests and 22 had radiographic venography. The results showed that impedance phlebography was highly variable and poorly reliable. False positive results were noted in 8 limbs (18%) and false negative results in 3 limbs (7%). Despite its being simple, rapid and noninvasive, its clinical usefulness is doubtful when performed according to the original method.

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