Limited Value of Single Sampling for IgM Antibody Determination as a Diagnostic Approach for Acute Hepatitis E Virus Infection

In immunocompetent patients with a suspicion of hepatitis E virus (HEV) infection, single IgM antibody testing is typically applied. In this prospective study, we aimed to evaluate the accuracy of three different HEV screening approaches in patients with acute hepatitis, including approaches based on IgM determination, HEV RNA detection, and the combination of both.

Five Commercial Immunoassays for SARS-CoV-2 Antibody Determination and Their Comparison and Correlation with the Virus Neutralization Test

There is an ongoing debate as to whether SARS-CoV-2 antibodies can be found in patients who have recovered from COVID-19 disease. Currently, there is no consensus on whether the antibodies, if present, are protective. Our regular measurements of SARS-CoV-2 antibodies, starting in July 2020, have provided us with the opportunity of becoming acquainted with the five different immunoassays. A total of 149 patients were enrolled in our study. We measured the samples using each immunoassay, then performing a virus neutralization test and comparing the results of SARS-CoV-2 antibodies with this test. We observed that the production of neutralizing antibodies is age-dependent. Elderly patients have a higher proportion of high neutralizing titers than young patients. Based on our results, and in combination with the literature findings, we can conclude that the serological SARS-CoV-2 antibody measurement is a helpful tool in the fight against COVID-19. The assays can provide information about the patient’s previous contact with the virus. Anti-spike protein assays correlate well with the virus neutralization test and can be used in the screening of potential convalescent plasma donors.

Search for asymptomatic carriers of SARS-CoV-2 in healthcare workers during the pandemic: a Spanish experience

Summary Background Asymptomatic carriers of SARS-CoV-2 can be a vehicle for transmission of the infection. This fact is of particular importance in the case of healthcare workers (HCWs). Design Cross-sectional study in HCWs in a medium size hospital in the South of Spain. Methods Between 15 and 25 April 2020, naso- and oropharyngeal PCR determination was performed together with IgG and IgM antibody determination by immunochromatography to the HCWs of the Costa del Sol Hospital in Marbella of the units involved in patient care with COVID-19: Emergencies, Intensive Care and Anesthesia, Internal Medicine and Pneumology. Other units not directly involved in the care of these patients were offered to participate. On the day of sampling, a health questionnaire was answered, reporting symptoms on the same day and in the previous 14 days. Results Four hundred and ninety-eight HCWs were studied. Two individuals were detected with PCR for SARS-CoV2 positive. Both were asymptomatic on the day of sampling, but one of them had had a COVID-19 compatible picture in the previous two weeks and had positive IgG and IgM; therefore, only one subject was truly asymptomatic carrier (0.2%). Nine workers with positive IgG (1.8%) were detected. Conclusions The prevalence of asymptomatic carriers among health workers of the services directly involved in the care of patients with COVID-19 was very low in our center. This type of strategy can be one more tool in controlling the pandemic.

Search for asymptomatic carriers of SARS-CoV-2 in healthcare workers during the pandemic: a Spanish experience

Objective: determine the percentage of healthcare workers (HCW) carrying SARS-CoV-2 in high exposure areas of the hospital. Design: cross- sectional study during April 15-24th in Hospital Costa del Sol (Marbella, Spain), excluding HCW with previous COVID19. Setting: hospital based, focused on patient care areas COVID19. Participants: 498 subjects, 80% women. Participation was offered to all the HCW of Emergencies, Intensive Care and Anesthesia, Internal Medicine and Pneumology. Other units not directly involved in the care of these patients were offered to participate. Intervention: naso and oropharyngeal PCR determination was performed together with IgG and IgM antibody determination by immunochromatography. On the day of sampling, a health questionnaire was answered, reporting symptoms on the same day and in the previous fourteen days. Main outcome measures: percentage of HCW with positive PCR for SARS-CoV-2, percentage of HCW with positive IgG for SARS-CoV-2. Results: Two individuals were detected with PCR for SARS-CoV-2 positive (0.4%). Both were asymptomatic on the day of sampling, but one of them had had a CoVID-19 compatible picture in the previous two weeks and had positive IgG and IgM; therefore, only one subject was truly asymptomatic carrier (0.2%). 9 workers with positive IgG (1.8%) were detected. Conclusions: the prevalence of asymptomatic carriers among health workers of the services directly involved in the care of patients with CoVID-19 was very low in our center. This type of strategy can be one more tool in controlling the pandemic.

An update on the management of low-risk differentiated thyroid cancer

Low-risk papillary cancers, which represent the vast majority of thyroid cancers diagnosed today, do not require aggressive treatment or follow-up. Initial treatment consists of a total thyroidectomy without prophylactic lymph node dissection. A hemithyroidectomy is an alternative in some patients with an intrathyroidal tumor and with a normal contralateral lobe at pre-operative neck ultrasonography. The use of post-operative radioiodine should be restricted to selected patients. Follow-up at 6–18 months is based on serum thyroglobulin (Tg), Tg-antibody determination and neck ultrasonography. In the absence of any abnormality (excellent response to treatment), the risk of recurrence is extremely low and follow-up may consist of serum TSH monitoring that is maintained in the normal range, and a Tg and Tg-antibody titer determination every year. There is no need for referral to a specialized center. In patients with detectable serum Tg or detectable Tg antibodies, the trend over time of these markers on levothyroxine treatment will dictate subsequent follow-up: a decreasing trend is reassuring, but an increasing trend should lead to imaging, starting with neck ultrasonography.

LGI1, CASPR2 and related antibodies: a molecular evolution of the phenotypes

Recent biochemical observations have helped redefine antigenic components within the voltage-gated potassium channel (VGKC) complex. The related autoantibodies may be now divided into likely pathogenic entities, which target the extracellular domains of leucine-rich glioma-inactivated 1 (LGI1) and contactin-associated protein-like 2 (CASPR2), and species that target intracellular neuronal components and are likely non-pathogenic. This distinction has enhanced clinical practice as direct determination of LGI1 and CASPR2 antibodies offers optimal sensitivity and specificity. In this review, we describe and compare the clinical features associated with pathogenic LGI1 and CASPR2 antibodies, illustrate emerging laboratory techniques for antibody determination and describe the immunological mechanisms that may mediate antibody-induced pathology. We highlight marked clinical overlaps between patients with either LGI1 or CASPR2 antibodies that include frequent focal seizures, prominent amnesia, dysautonomia, neuromyotonia and neuropathic pain. Although occurring at differing rates, these commonalities are striking and only faciobrachial dystonic seizures reliably differentiate these two conditions. Furthermore, the coexistence of both LGI1 and CASPR2 antibodies in an individual occurs surprisingly frequently. Patients with either antibody respond well to immunotherapies, although systematic studies are required to determine the magnitude of the effect beyond placebo. Finally, data have suggested that CASPR2 and LGI1 modulation via genetic or autoimmune mechanisms may share common intermediate molecules. Taken together, the biochemical distinction of antigenic targets has led to important clinical advances for patient care. However, the striking syndrome similarities, coexistence of two otherwise rare antibodies and molecular insights suggest the VGKC complex may yet be a common functional effector of antibody action. Hence, we argue for a molecular evolution alongside a clinical and phenotypic re-evaluation.