Comparison of immunofluorescence and enzyme-linked immunosorbent assays for the serology of hantavirus infections.

Three enzyme-linked immunosorbent assay (ELISA) systems based upon different principles were developed for the serology of Hantaan virus infections and compared with an indirect immunofluorescence assay (IFA). The indirect IFA was carried out with gamma-irradiated Hantaan virus-infected and uninfected Vero E6 cells fixed with ethanol (-70 degrees C) or acetone (20 degrees C) on drop slides and a FITC-coupled sheep anti-human Ig preparation. Atypical staining in the IFA was avoided by using ethanol (-70 degrees C) instead of acetone (20 degrees C) fixation. In the first ELISA ('cell-assay'), Hantaan virus-infected or uninfected Vero E6 cells were used as antigens, which after gamma-irradiation were seeded into microtiter ELISA strips. Serial dilutions of human sera were incubated and specific antibodies were demonstrated with a horseradish peroxidase (HRPO)-conjugated sheep anti-human Ig preparation. In the second ELISA ('competition-assay') an affinity-purified human Ig preparation was used as a capture antibody for Hantaan virus antigen. After incubation of serial dilutions of human sera with this coat, the reactivity of the affinity purified anti-Hantaan virus Ig coupled to HRPO was determined. In the third ELISA ('complex trapping blocking [CTB]-assay') the same capture antibody was used to react with a mixture of the antigen and serial dilutions of human sera. The reactivity with the same HRPO conjugate was then determined. The results obtained in the respective assay systems with sera from people at risk or suspected of Hantaan virus infection coincided well. The CTB-ELISA proved to be faster and more sensitive than both the other ELISA systems, without giving more non-specific reactions: it detected almost all the IFA positive samples.(ABSTRACT TRUNCATED AT 250 WORDS

Viewpoint: filovirus haemorrhagic fever outbreaks: much ado about nothing?

The recent outbreak of Marburg haemorrhagic fever in the Democratic Republic of Congo has put the filovirus threat back on the international health agenda. This paper gives an overview of Marburg and Ebola outbreaks so far observed and puts them in a public health perspective. Damage on the local level has been devastating at times, but was marginal on the international level despite the considerable media attention these outbreaks received. The potential hazard of outbreaks, however, after export of filovirus from its natural environment into metropolitan areas, is argued to be considerable. Some avenues for future research and intervention are explored. Beyond the obvious need to find the reservoir and study the natural history, public health strategies for a more timely and efficient response are urgently needed

Comparison of two enzyme-linked immunosorbent assays and one rapid immunoblot assay for detection of herpes simplex virus type 2-specific antibodies in serum

The sensitivities and specificities of three immunoassays for the detection of herpes simplex virus type 2 (HSV-2)-specific immunoglobulin G antibodies in serum, including the one-strip rapid immunoblot assay (RIBA; Chiron Corporation) and two indirect enzyme immunosorbent assays (EIA; Gull Laboratories and Centocor), were compared by testing a panel of 1,250 serum samples from individuals attending an outpatient clinic for sexually transmitted diseases. A qualitative agreement among the three assays was observed with 1,080 serum samples (86.4%); 291 of the serum samples (23.3%) were positive, 789 samples (63.1%) were negative, and 170 serum samples (13.6%) gave a discordant result. Results were considered conclusive when a concordant result was obtained with two of three assays. The sensitivities and specificities of the RIBA, the Gull EIA, and the Centocor EIA proved to be 99.2, 99.7, and 89.9% and 97.1, 96.7, and 99.3%, respectively. These results indicate that the Chiron RIBA and the Gull EIA are especially useful and reliable fo

Pulmonary diffusing capacity disturbances are related to nailfold capillary changes in patients with Raynaud's phenomenon with and without an underlying connective tissue disease

PURPOSE: The aim of this study was to evaluate whether pulmonary microvascular damage is part of a more generalized involvement of the microvasculature in the spectrum of scleroderma (Scl)-like syndromes. PATIENTS AND METHODS: We studied four groups of patients, all with Raynaud's phenomenon (RP), distinguished by the extent and nature of their underlying connective tissue disease. Twenty-two patients had primary RP (pRP), another 22 patients had RP and an undifferentiated connective tissue disease (uCTD), 15 patients had Scl, and eight patients had the CREST syndrome (CREST). Pulmonary vascular damage in these groups was assessed by measuring the pulmonary diffusing capacity (T1,CO) and its components: the diffusing capacity of the alveolocapillary membrane (Dm) and the pulmonary capillary blood volume (Vc). Results were compared with morphologic abnormalities of the nailfold capillaries, as determined by nailfold capillary microscopy, and related to the presence of antinuclear antibodies. RESULTS: Vc was below normal in 38% and 43% of patients with pRP and uCTD, respectively (versus 52% in patients with Scl or CREST combined). In contrast, Dm was below normal in only 5% and 26% of patients with pRP and uCTD, respectively (versus 61% in patients with Scl or CREST combined). In patients with Scl and CREST, Dm was significantly decreased as compared with the former groups (p less than 0.01). Dm was also the pulmonary function parameter that correlated most strongly with both nailfold capillary abnormalities and the presence of antinuclear antibodies, whereas Vc did not. CONCLUSION: Early pulmonary involvement in Scl syndromes is functionally characterized by a lowered Dm, correlating with morphologic changes of the nailfold capillaries. Decreased Vc is probably a reflection of RP of the pulmonary vasculature

Nationwide Real-world Cohort Study of First-line Tyrosine Kinase Inhibitor Treatment in Epidermal Growth Factor Receptor-mutated Non-small-cell Lung Cancer

Most trials regarding tyrosine kinase inhibitors in patients with advanced epidermal growth factor receptor-mutated non-small-cell lung cancer comprised selected series from Asian populations. We found that Western European patients with epidermal growth factor receptor-mutated non-small-cell lung cancer who received first-line treatment with regular tyrosine kinase inhibitors have a median overall survival of 20.2 months in our large nationwide real-world cohort. In patients with brain metastasis, erlotinib showed superior results compared with gefitinib and was similar to afatinib. Background: Only a few randomized trials directly compared the relative efficacy of tyrosine kinase inhibitors (TKIs) in patients with advanced epidermal growth factor receptor (EGFR)-mutated non-small-cell lung cancer (NSCLC), and most trials comprised selected series from Asian populations. Therefore, the aim of this study was to assess the overall survival (OS) of advanced EGFR-mutated NSCLC in a large white population and to evaluate variation between different TKIs and identify predictors of survival. Patients and Methods: Information about clinical characteristics, treatment, and survival for 873 patients with stage IV EGFR + NSCLC, diagnosed from 2015 through 2017, was derived from the Netherlands Cancer Registry. OS was evaluated by actuarial analysis and multivariable Cox regression. Prognostic factors are reported as hazard ratios and 95% confidence intervals. Results: A total of 596 (68%) patients received first-line treatment with regular TKIs, providing a median survival of 20.2 months. Forty-five percent of patients were 70 years and older, and 54% of patients had distant metastasis in multiple organs. In the multivariate analysis, survival was significantly worse for men, and patients with higher age, poorer performance, and >= 3 organs with metastasis. Compared with erlotinib, OS was worse for gefitinib users (adjusted hazard ratio, 1.30; 95% confidence interval, 1.02-1.64), predominantly in patients with brain metastasis. Conclusion: Dutch patients with EGFR-mutated NSCLC who received first-line treatment with regular TKIs have a median OS of 20.2 months in a nationwide real-world cohort. In patients with brain metastasis, erlotinib showed superior results compared with gefitinib and was similar to afatinib. (C) 2020 Elsevier Inc. All rights reserved

Small-cell lung cancer patients are just ‘a little bit’ tired: response shift and self-presentation in the measurement of fatigue

Background: Response shift has gained increasing attention in the measurement of health-related quality of life (QoL) as it may explain counter-intuitive findings as a result of adaptation to deteriorating health. Objective: To search for response shift type explanations to account for counter-intuitive findings in QoL measurement. Methods: Qualitative investigation of the response behaviour of small-cell lung cancer (SCLC) patients (n = 23) in the measurement of fatigue with The European Organization for Research and Treatment of Cancer Core Quality of Life Questionnaire (EORTC QLQ-C30) question 'were you tired'. Interviews were conducted at four points during 1st line chemotherapy: at the start of chemotherapy, 4 weeks later, at the end of chemotherapy, and 6 weeks later. Patients were asked to 'think aloud' when filling in the questionnaire. Results: Fifteen patients showed discrepancies between their answer to the EORTC question 'were you tired' and their level of fatigue spontaneously reported during the interview. These patients chose the response options 'not at all' or 'a little' and explained their answers in various ways. In patients with and without discrepancies, we found indications of recalibration response shift (e.g. using a different comparison standard over time) and of change in perspective (e.g. change towards a more optimistic perspective). Patients in the discrepancy group reported spontaneously how they dealt with diagnosis and treatment, i.e. by adopting protective and assertive behaviour and by fighting the stigma. They distanced themselves from the image of the stereotypical cancer patient and presented themselves as not suffering and accepting fatigue as consequence of treatment. Conclusion: In addition to response shift, this study suggests that 'self-presentation' might be an important mechanism affecting QoL measurement, particularly during phases when a new equilibrium needs to be found