ABSTRACT
BACKGROUND Most individuals with Covid-19 infection develop antibodies specific to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However, the dynamics of these antibodies is variable and not well-studied. We aimed to determine the titres of naturally acquired antibodies over a 12-week follow-up. METHODS We recruited healthcare workers who had tested positive on a specific quantitative reverse transcription-polymerase chain reaction (qRT-PCR) for SARS-CoV-2, and then tested for the presence of immunoglobulin G (IgG) antibody against the same virus at baseline and again at 6 and 12 weeks. The antibody titre was determined by a semi-quantitative assay based on signal/cut-off ratio. Healthcare workers with antibody positivity were divided into those with high titre (ratio ?12) and low titre (<12). Their demographic details and risk factors were surveyed through a Google form and analysed in relation to the antibody titres at three time-points. RESULTS Of the 286 healthcare workers, 10.48% had high antibody titres. Healthcare workers who had tested positive by qRT-PCR and those who had received the Bacille Calmette–Guérin (BCG) vaccination or other immune-boosters had a higher frequency of high antibody titres. While there was a significant decline in antibody titres at 6 and 12 weeks, 87.46% of individuals positive for IgG antibody persisted to have the antibody even at 12 weeks. CONCLUSION Healthcare workers who tested positive for SARS-CoV-2 on qRT-PCR had a high positivity for the specific antibody, which continued to express in them even at 12 weeks. Further follow-up is likely to enhance our understanding of antibody kinetics following SARS-CoV-2 infection.
ABSTRACT
Background: Many different treatment modalities have been advocated by different authors from time to time for lumbarspondylolisthesis. Many cases, the condition can be treated conservatively. However, when the symptoms persist, surgeryneeds to be performed. The principle of underlying surgery includes stabilization of the slipping vertebrae. Various operativemethods encompassing this principle include stabilization with pedicle screw fixation and fusion which can either posterolateralor interbody fusion, anterior lumbar interbody fusion, posterior lumbar interbody fusion, or transforaminal lumbar interbodyfusion. The objective of this study was to compare the surgical efficacy in terms of stability and fusion achieved using pediclescrew-rod instrumentation with posterolateral fusion and pedicle screw-rod instrumentation with interbody fusion in lumbarspondylolisthesis and to study THE functional and clinical recovery using the Revised Oswestry Disability Index score.Materials and Methods: A prospective study was carried out to compare the clinical and radiological outcomes between Pediclescrew-rod instrumentation with either posterolateral fusion and interbody fusion after adequate decompression in patient oflumbar spondylolisthesis. All patients as per the inclusion criteria were admitted, underwent surgery between March 2010 andMarch 2012, and were included in the study.Results: The total of 50 patients was included in our study. Both male and female patients were equally distributed in both thegroups, wherein postreolateral fusion had 13 female patients and those with interbody fusion had 13 male patients. Our studyshows marked improvement in Revised Oswestry Disability score postoperatively with good-to-excellent results in both thegroups. We achieved good solid radiological fusion earliest on the 3rd month in both the groups with good stability.Conclusion: Our results showed similar clinical and functional outcome in both the groups with no significant statistical differencefound. However, we conclude that in cases where reduction is required and there is instability affecting the three column ofspine interbody fusions with pedicle screws-rod instrumentation provide a more solid mechanical construct.