Do fully automated immunoassays for the evaluation of the immune response to SARS-CoV-2 are commutable?

On December 30, 2019, the city of Wuhan, China, experienced an outbreak of unexplained pneumonia. From January 7, 2020, a new betacoronavirus, severe acute respiratory syndrome coronavirus was identified (SARS-CoV-2). The World Health Organization (WHO) has since declared a pandemic with millions of confirmed cases worldwide. As part of the fight against the epidemic, laboratories have a critical role in assessing the reliability of new serological assays before taking part of diagnostic protocols or made available broader to the community and to evaluate commutability between assays. The aim of this study was to perform a comparison between two automated assays for SARS-CoV-2 IgG testing, the MAGLUMI ® 800 and the LIAISON ® XL. Among the patients confirmed positive for COVID-19, the two automated assays were significantly correlated (r = 0.811; p < 0.0001). The overall concordance made for MAGLUMI 2019-nCoV IgG positive/negative vs. LIAISON® SARS-CoV-2 IgG positive/negative results was 79% (Index Kappa of Cohen). We list the discrepancies between the two analyzers among the 44 tested patients. In conclusion, the overall agreement between the two automated assays for SARS-CoV-2 was good. However, the MAGLUMI assay might be more sensitive at the early stages of antibody development and there is a lack of specificity with LIAISON XL.

Epidemiological aspects and molecular characterization of the hepatitis B virus among blood donors in Lubumbashi, Democratic Republic of Congo.

OBJECTIVES: The strains of HBV circulating among blood donors in Lubumbashi, Democratic Republic of Congo (DRC), are not yet characterized. The purpose of this study was to determine seroprevalence, changes in biochemical parameters during HBV infection and molecular characterization of HBV in blood donors in Lubumbashi. METHODS: The detection of HBsAg was carried out by rapid diagnostic test then confirmed by the Liaison XL® Quant HBsAg technique. PCR targeting the P gene was carried out on LightCycler® 96 and genotyping by the sequencing technique on ABI 3500. RESULTS: The seroprevalence was 7.9%. The genotypes E (53.1%), A (41.8%), A3/E (3.8%), A1/E (1.3%) and some drug resistance mutations were identified. Disturbances of HDL-cholesterol, direct bilirubin, transaminases (ASAT and ALAT), PAL, GGT and albumin have been observed in HBsAg positive blood donors. CONCLUSION: The results of our study indicated that Lubumbashi is in a region with high endemicity for HBV and report for the first time HBV of genotypes A, E, A1/E and A3/E. They highlight the need to implement strategies to improve transfusion safety in blood transfusion centers and hospital blood banks in Lubumbashi in order to reduce HBV infection in recipients. They could also contribute to the implementation of treatment strategies and the development of mapping of circulating HBV genotypes in the DRC.

Clinical characteristics and humoral immune response in healthcare workers with COVID-19 in a teaching hospital in Belgium.

BACKGROUND: Healthcare workers (HCWs) are at high risk of acquiring COVID-19 and could play a role in nosocomial transmission. Since 4th February 2020, Belgian Health authorities reported more than 90,568 cases, of which 8.3% were HCWs. Data on clinical characteristics, sources of infection and humoral immune response of HCWs with COVID-19 remain scarce. AIM: To analyse the clinical characteristics, humoral immune response, sources of contamination, and outcomes among HCWs with COVID-19. METHODS: This retrospective study included 176 HCWs with laboratory-confirmed COVID-19 in a teaching hospital in Belgium. Between 1st March and 31st May 2020, all HCWs with symptoms suspected of COVID-19 were tested by reverse transcription polymerase chain reaction on a nasopharyngeal swab. Serological testing was performed between 55 and 137 days after the onset of symptoms. FINDINGS: Median age was 40.8 years and 75% were female. Median delay between onset of symptoms and diagnosis was 4.39 days. Most frequent symptoms were cough and headache (both 75%). Fever accounted for 68.7%. Most represented professions were nurses (42%). HCWs were mainly infected by patient contact (32.9%); 7.6% required hospitalization and 1.7% were admitted to the intensive care unit. Unfortunately, one HCW died (0.5%). Total antibodies were positive in 109/126 (86.5%). CONCLUSIONS: Clinical presentation of COVID-19 in HCWs does not differ from the general population. However, outcomes were more favourable with a mortality rate lower than that reported in Belgian COVID-19 patients in general (16%). The main source of infection was the hospital setting. Our positive antibodies rate was high but lower than previously reported.

Immunisation after hepatitis B polyvalent vaccination among children in South Kivu Province, Democratic Republic of the Congo.

BACKGROUND: The World Health Organization recommends the integration of vaccination against hepatitis B virus (HBV) into the national immunisation programmes of all highly endemic countries. Protective efficacy, defined as a hepatitis B surface antibody (HBsAb) level ≥10 mIU/mL, is ideally obtained in >90 - 95% of immunised children. The Democratic Republic of the Congo (DRC) implemented this recommendation in 2007 by introducing administration of hepatitis B vaccine in a combined formulation. OBJECTIVES: To assess the rate of seroprotection in children who received hepatitis B vaccine in the DRC context. METHODS: This descriptive cross-sectional study was conducted during routine postnatal consultations at the General Hospital of Bukavu in South Kivu Province, DRC. A total of 200 infants aged 6 - 12 months and their mothers were consecutively enrolled. All the infants received the three-dose regimen of hepatitis B vaccine 6, 10 and 14 weeks after birth. The mothers were tested for hepatitis B surface antigen and HIV, while HBsAb levels were measured in the infants to determine immune response. RESULTS: Seroprotection was achieved in 84.5% of the infants. No maternal (age, parity, duration of pregnancy, HIV and HBV status) or infant (sex, weight at birth) factors were found to be associated with absence of immunological response. CONCLUSIONS: The study demonstrated that the rate of seroprotection in the current vaccination programme against HBV in DRC was lower than desirable but comparable to rates reported in some other African countries. Further studies are needed to assess this finding and to evaluate ways to optimise the seroprotection rate.

Outcome of hepatitis B and C virus-associated hepatocellular carcinoma occurring after renal transplantation.

Kidney transplant recipients (KTR) are subjected to immunosuppressive therapy that can enhance hepatitis B and C virus replication, leading to cirrhosis and hepatocellular carcinoma (HCC). The aim of this study was to assess the prevalence and outcome of HCC in KTR. Case-control study. Patients with chronic HBV and/or HCV infection who underwent kidney transplantation between 1976 and 2011 and subsequently developed HCC were compared to a control group of patients with chronic HBV and/or HCV infection, matched for gender and age at HCC diagnosis, who did not receive kidney transplantation. Among 2944 KTR, 330 had hepatitis B and/or C. Fourteen developed HCC, a period prevalence of 4.2%. Age at HCC diagnosis was 52.6 ± 6.5 years (53.5 ± 5.7 in controls, P=.76). Time between transplantation and HCC diagnosis was 16.7 ± 2.7 years. Six HCCs were related to HBV, six to HCV and two to co-infection with HBV and HCV. Immunosuppressive therapy was comparable in HBV, HCV and HBV+HCV patients. At diagnosis, 71% of patients met Milan criteria (65% in the control group, P=.4). Alpha-fetoprotein levels, tumour characteristics and treatment modalities were comparable between both groups. Patient survival 2 years after HCC diagnosis was 28% in KTR, compared to 68% in controls (P=.024). Survival after HCC diagnosis is significantly worse in KTR compared to nontransplanted patients with HBV and/or HCV. Prevention is crucial and should be based on viral eradication/suppression before or after transplantation.

Technical and clinical validation of three commercial real-time PCR kits for the diagnosis of neuroborreliosis in cerebrospinal fluid on three different real-time PCR platforms.

This study reports the evaluation of the technical and clinical validation of the O-DiaBorburg kit (DIA), Borrelia burgdorferi PCR kit, ISEX (GENE), and Borrelia burgdorferi sensu lato Real-TM (SAC) for the diagnosis of neuroborreliosis in cerebrospinal fluid based on both Borrelia DNA and CSF samples from patients with clinical suspicion of neuroborreliosis. This validation study was done by analysing the kits on the Rotorgene Q (RGQ), CFX96, and LightCycler480 (LC480). For all kits, the linear range was larger on RGQ than on CFX96 and LC480. A good reproducibility was obtained for all assays on all instruments. Storage at -20 °C resulted in a decreased reproducibility for SAC. Results of the limit of detection (LOD95) experiments indicated a better sensitivity than described in the kit insert for all kits on all PCR platforms. No cross-reactivity was found for genetically related organisms nor for other pathogens which may be present in CSF. All species of the Borrelia burgdorferi sensu lato complex were detected with the GENE and SAC kits. The DIA kit failed to detect B. lusitaniae. The results seemed to indicate a better overall performance for the GENE kit on RGQ. However, its diagnostic value could not be confirmed in the clinical validation study, wherein none of the 103 CSF samples from clinical neuroborreliosis cases showed a positive real-time PCR result with the GENE kit analysed on RGQ.

Progress and Perspectives on HIV-1 microbicide development.

The majority of HIV-1 infections occur via sexual intercourse. Women are the most affected by the epidemic, particularly in developing countries, due to their socio-economic dependence on men and the fact that they are often victims of gender based sexual violence. Despite significant efforts that resulted in the reduction of infection rates in some countries, there is still need for effective prevention methods against the virus. One of these methods for preventing sexual transmission in women is the use of microbicides. In this review we provide a summary of the progress made toward the discovery of affordable and effective HIV-1 microbicides and suggest future directions. We show that there is a wide range of compounds that have been proposed as potential microbicides. Although most of them have so far failed to show protection in humans, there are many promising ones currently in pre-clinical studies and in clinical trials.

Griffithsin tandemers: flexible and potent lectin inhibitors of the human immunodeficiency virus.

BACKGROUND: The lectin griffithsin (GRFT) is a potent antiviral agent capable of prevention and treatment of infections caused by a number of enveloped viruses and is currently under development as an anti-HIV microbicide. In addition to its broad antiviral activity, GRFT is stable at high temperature and at a broad pH range, displays little toxicity and immunogenicity, and is amenable to large-scale manufacturing. Native GRFT is a domain-swapped homodimer that binds to viral envelope glycoproteins and has displayed mid-picomolar activity in cell-based anti-HIV assays. Previously, we have engineered and analyzed several monomeric forms of this lectin (mGRFT) with anti-HIV EC50 values ranging up to 323 nM. Based on our previous analysis of mGRFT, we hypothesized that the orientation and spacing of the carbohydrate binding domains GRFT were key to its antiviral activity. RESULTS: Here we present data on engineered tandem repeats of mGRFT (mGRFT tandemers) with antiviral activity at concentrations as low as one picomolar in whole-cell anti-HIV assays. mGRFT tandemers were analyzed thermodynamically, both individually and in complex with HIV-1 gp120. We also demonstrate by dynamic light scattering and cryo-electron microscopy that mGRFT tandemers do not aggregate HIV virions. This establishes that, although the intra-virion crosslinking of HIV envelope glycoproteins is likely integral to their activity, the antiviral activity of these lectins is not due to virus aggregation caused by inter-virion crosslinking. CONCLUSIONS: The engineered tandemer constructs of mGRFT may provide novel and powerful agents for prevention of infection by HIV and other enveloped viruses.

Mechanisms of HIV-1 subtype C resistance to GRFT, CV-N and SVN.

We examined the ability of HIV-1 subtype C to develop resistance to the inhibitory lectins, griffithsin (GRFT), cyanovirin-N (CV-N) and scytovirin (SVN), which bind multiple mannose-rich glycans on gp120. Four primary HIV-1 strains cultured under escalating concentrations of these lectins became increasingly resistant tolerating 2 to 12 times their 50% inhibitory concentrations. Sequence analysis of gp120 showed that most had deletions of 1 to 5 mannose-rich glycans. Glycosylation sites at positions 230, 234, 241, 289 located in the C2 region and 339, 392 and 448 in the C3-C4 region were affected. Furthermore, deletions and insertions of up to 5 amino acids in the V4 region were observed in 3 of the 4 isolates. These data suggest that loss of glycosylation sites on gp120 as well as rearrangement of glycans in V4 are mechanisms involved in HIV-1 subtype C escape from GRFT, CV-N and SVN.

UCLA1, a synthetic derivative of a gp120 RNA aptamer, inhibits entry of human immunodeficiency virus type 1 subtype C.

Entry of human immunodeficiency virus type 1 (HIV-1) into cells is mediated by the virion surface envelope (Env) glycoproteins, making it a desirable target for antiretroviral entry inhibitors. We previously isolated a family of gp120 binding RNA aptamers and showed that they neutralized the infectivity of HIV-1. In this study, we assessed the activity of a shortened synthetic derivative of the B40 aptamer, called UCLA1, against a large panel of HIV-1 subtype C viruses. UCLA1 tightly bound to a consensus HIV-1 subtype C gp120 and neutralized isolates of the same subtype with 50% inhibitory concentrations (IC(50)s) in the nanomolar range. The aptamer had little toxicity in tests with cell lines and primary cells. Furthermore, it exhibited high therapeutic indices, suggesting that it may be effective at very low doses. Mapping of UCLA1 binding sites on gp120 revealed eight amino acid residues that modulated neutralization resistance. This included residues within the coreceptor binding site, at the base of the V3 loop, and in the bridging sheet within the conserved V1/V2 stem-loop of gp120. The aptamer was also shown to have synergistic effects with T20, a gp41 fusion inhibitor, and IgG1b12 (b12), an anti-CD4 binding site monoclonal antibody. These results suggest that UCLA1 may be suitable for development as a potent HIV-1 entry inhibitor.

The lectins griffithsin, cyanovirin-N and scytovirin inhibit HIV-1 binding to the DC-SIGN receptor and transfer to CD4(+) cells.

It is generally believed that during the sexual transmission of HIV-1, the glycan-specific DC-SIGN receptor binds the virus and mediates its transfer to CD4(+) cells. The lectins griffithsin (GRFT), cyanovirin-N (CV-N) and scytovirin (SVN) inhibit HIV-1 infection by binding to mannose-rich glycans on gp120. We measured the ability of these lectins to inhibit both the HIV-1 binding to DC-SIGN and the DC-SIGN-mediated HIV-1 infection of CD4(+) cells. While GRFT, CV-N and SVN were moderately inhibitory to DC-SIGN binding, they potently inhibited DC-SIGN-transfer of HIV-1. The introduction of the 234 glycosylation site abolished HIV-1 sensitivity to lectin inhibition of binding to DC-SIGN and virus transfer to susceptible cells. However, the addition of the 295 glycosylation site increased the inhibition of transfer. Our data suggest that GRFT, CV-N and SVN can block two important stages of the sexual transmission of HIV-1, DC-SIGN binding and transfer, supporting their further development as microbicides.

Impact of steroid-avoidance immunosuppression on long-term outcome after liver transplantation for HCV cirrhosis: the need for well documented long-term follow-up.

AIM: study impact of steroid avoidance on HCV recurrence after transplantation. METHODS AND MATERIAL: 35 HCV pats, being part of prospective, randomized, double-blind, placebo-controlled study comparing Tacrolimus (TAC)-Placebo (PLAC) (n = 14) to TAC-short-term (2 mo) low-dose steroid (STER) (n = 21), had 5 years follow-up. Primary endpoint was 1 and 5 years survival; secondary (composite) endpoint comprised HCV related cirrhosis, re-transplantation (re-LT) and death. RESULTS: 1 and 5-years survival were 93% and 75% in TAC-PLAC group; 91% and 66% in TAC-STER group (p 0.38). Two (14.3%) TAC-PLAC pats died due to HCV cirrhosis at 54 and 72 mo; 7 (33%) TAC-STER pats died due to cholestatic hepatitis at 5.8 and 9 mo, to cirrhosis at 18, 22, 34, 73 and 79 mo (p 0.20). Composite endpoint at 5 years didn't show advantage in favor of TAC-PLAC patients (5/14 [35.7%] vs. 9/21 [42.8%] pts, p.0.69). Early biopsies seemed more favorable in TAC-PLAC pats; at 5 years results were identical for both groups. Only 1 (7.1%) TAC-PLAC and 2 (9.5%) TAC-STER pats needed rejection treatment. CONCLUSION: immunosuppression using steroid avoidance or short-term use had similar outcomes. Well documented long-term follow-up, including biopsies, is necessary in order to make conclusions in relation to impact of steroid use on outcome of HCV liver recipients.

Hepatitis E virus: an underdiagnosed cause of chronic hepatitis in renal transplant recipients.

Hepatitis E virus (HEV) infection can evolve to chronic hepatitis in immunocompromised patients leading to rapidly progressive cirrhosis. Proper diagnosis is therefore important, as reducing immunosuppressive therapy can allow clearance of the virus. We report a case of chronic HEV infection in a renal transplant recipient that went undiagnosed for many years, discuss the therapeutic options, and review the current available literature.

Mannose-rich glycosylation patterns on HIV-1 subtype C gp120 and sensitivity to the lectins, Griffithsin, Cyanovirin-N and Scytovirin.

Griffithsin (GRFT), Cyanovirin-N (CV-N) and Scytovirin (SVN) are lectins that inhibit HIV-1 infection by binding to multiple mannose-rich glycans on the HIV-1 envelope glycoproteins (Env). Here we show that these lectins neutralize subtype C primary virus isolates in addition to Env-pseudotyped viruses obtained from plasma and cervical vaginal lavages. Among 15 subtype C pseudoviruses, the median IC(50) values were 0.4, 1.8 and 20.1nM for GRFT, CV-N and SVN, respectively, similar to what was found for subtype B and A. Analysis of Env sequences suggested that concomitant lack of glycans at positions 234 and 295 resulted in natural resistance to these compounds, which was confirmed by site-directed mutagenesis. Furthermore, the binding sites for these lectins overlapped that of the 2G12 monoclonal antibody epitope, which is generally absent on subtype C Env. This data support further research on these lectins as potential microbicides in the context of HIV-1 subtype C infection.

Poliomyelitis-like syndrome with matching magnetic resonance features in a case of Lyme neuroborreliosis.

Lyme disease is a multisystemic disorder caused by an epizootic organism of the spirochete group, called Borrelia burgdorferi, which is transmitted to humans by ticks of the genus Ixodes. Lyme neuroborreliosis may occur during the early dissemination phase, most often as a painful meningo-radiculitis and very rarely as a radiculo-myelitis, whereas encephalomyelitis is observed in the late phase. We report the case of a patient with an early subacute poliomyelitis-like syndrome closely matching the selective involvement of the anterior horns and roots of the cervical spinal cord seen on magnetic resonance imaging. This condition improved with appropriate antibiotics.

Poliomyelitis-like syndrome with matching magnetic resonance features in a case of Lyme neuroborreliosis.

Lyme disease is a multisystemic disorder caused by an epizootic organism of the spirochete group, called Borrelia burgdorferi (Bb), which is transmitted to humans by ticks of the genus Ixodes. Lyme neuroborreliosis may occur during the early dissemination phase, most often as a painful meningo-radiculitis and very rarely as a radiculo-myelitis, whereas encephalomyelitis is observed in the late phase. We report the case of a patient with an early subacute poliomyelitis-like syndrome closely matching the selective involvement of the anterior horns and roots of the cervical spinal cord seen on magnetic resonance (MR) imaging. This condition improved with appropriate antibiotics.

Acute ischaemic pontine stroke revealing lyme neuroborreliosis in a young adult.

We report the case of a 23-year-old male patient who suddenly developed right hemiparesis, cerebellar ataxia, dysarthria, and bilateral dysmetria. Brain magnetic resonance (MR) examination demonstrated hyperacute ischaemic lesions within the pons. CSF analysis revealed a high protein content, lymphocytic pleocytosis, and oligoclonal IgG bands not present in the serum. Elevated IgM and IgG anti-Borrelia burgdorferi antibodies were shown in both serum and CSF samples, associated with an intrathecal synthesis of these antibodies. Ischaemic CNS lesions have been rarely observed as the first manifestation of Lyme neuroborreliosis. The putative mechanism for parenchymal ischaemia is the local extension of inflammatory changes from meninges to the wall of penetrating arterioles.

Hospital outbreak of gastroenteritis due to Norovirus in Belgium.

We report an outbreak of gastroenteritis due to Norovirus in a care unit in a Belgian hospital involving thirty-three people. The origin of the outbreak was traced to one nursing assistant. The virus strain identified by reverse transcription polymerase chain reaction and electron microscopy belonged to the genogroup II.