Impact of the COVID-19 pandemic on lung transplant patients and on a cohort of patients with rare lung disease: A single-center study.

INTRODUCTION: Due to the COVID-19 pandemic, France underwent several lockdown periods during 2020. Our aim was to evaluate its clinical and social impact on lung transplant (LT) patients treated at Strasbourg University Hospital, by comparing three periods: first lockdown (T1: March-May 2020), end of the first lockdown (T2: May-October 2020), and second lockdown (T3: November-December 2020) and the incidence of COVID-19 infections. A cohort of patients with rare lung disease (RLD) was also studied during T2. METHODS: We used clinical and paraclinical data collected during routine follow-up. A questionnaire was submitted to each patient at each period to assess their lifestyle, adherence to protective measures against COVID-19, contacts with their family and friends, and contagion risk. The incidence of new COVID-19 cases was also assessed. RESULTS: Overall, 283 LT and 57 RLD patients were included. We observed only eight COVID-19 cases over the three periods (n = 4 during T1, n = 0 during T2, and n = 4 during T3) in LT patients, with 37.5 % of patients hospitalized, no ICU transfers, and 100 % favorable outcomes. No case of COVID-19 was diagnosed in the RLD cohort. When comparing the three periods in the LT group, fewer patients limited their out-of-home activities during T2 (p < 0.0001). The frequency of these activities increased after the first lockdown, for the purchase of basic necessities (p < 0.0001), and professional activity continued (p = 0.008). We observed a significant increase in unscheduled medical consultations and in the prescription of anti-infective treatments during the end of the lockdown (p = 0.0002 and p = 0.005, respectively). Adherence to lockdown and to protective measures was high in both groups of patients. CONCLUSION: COVID-19 incidence remained low in both groups and there were significant lifestyle evolutions in LT patients and in those with RLD between first and second lockdown.

Torque teno virus viral load predicts SARS-CoV-2 vaccine response in kidney transplant recipients.

Transplant recipients display poor responses to SARS-CoV-2 mRNA vaccines. In this retrospective study, we investigate torque teno virus (TTV) viral load (VL), a ubiquitous virus reflecting global immune response levels, as a predictive factor of vaccine response in kidney transplant recipients (KTR). Four hundred and fifty-nine KTR having received two SARS-CoV-2 mRNA vaccine doses were enrolled, and 241 of them subsequently received a third vaccine dose. Antireceptor-binding domain (RBD) IgG response was assessed after each vaccine dose and TTV VL was measured in pre-vaccine samples. Prevaccine TTV VL > 6.2 log10 copies (cp)/mL was independently associated with nonresponse to two doses (odds ratio (OR) = 6.17, 95% confidence interval (CI95) = 2.42-15.78) as well as to three doses (OR = 3.62, 95% CI95 = 1.55-8.49). In nonresponders to the second dose, high TTV VL in prevaccine samples or measured before the third dose were equally predictive of lower seroconversion rates and antibody titers. High TTV VL before and during SARS-CoV-2 vaccination schedules are predictive of poor vaccine response in KTR. This biomarker should be further evaluated regarding other vaccine responses.

Efficacy of three COVID-19 vaccine doses in lung transplant recipients: a multicentre cohort study.

QUESTION ADDRESSED BY THE STUDY: Do three coronavirus disease 2019 (COVID-19) vaccine doses induce a serological response in lung transplant recipients? METHODS: We retrospectively included 1071 adults (551 (52%) males) at nine transplant centres in France. Each had received three COVID-19 vaccine doses in 2021, after lung transplantation. An anti-spike protein IgG response, defined as a titre >264 BAU·mL-1 after the third dose (median (interquartile range (IQR)) 3.0 (1.7-4.1) months), was the primary outcome and adverse events were the secondary outcomes. Median (IQR) age at the first vaccine dose was 54 (40-63) years and median (IQR) time from transplantation to the first dose was 64 (30-110) months. RESULTS: Median (IQR) follow-up after the first dose was 8.3 (6.7-9.3) months. A vaccine response developed in 173 (16%) patients. Factors independently associated with a response were younger age at vaccination, longer time from transplantation to vaccination and absence of corticosteroid or mycophenolate therapy. After vaccination, 51 (5%) patients (47 non-responders (47/898 (5%)) and four (4/173 (2%)) responders) experienced COVID-19, at a median (IQR) of 6.6 (5.1-7.3) months after the third dose. No responders had severe COVID-19 compared with 15 non-responders, including six who died of the disease. CONCLUSIONS: Few lung transplant recipients achieved a serological response to three COVID-19 vaccine doses, indicating a need for other protective measures. Older age and use of mycophenolate or corticosteroids were associated with absence of a response. The low incidence of COVID-19 might reflect vaccine protection via cellular immunity and/or good adherence to shielding measures.

Torque teno virus DNA load as a predictive marker of antibody response to a three-dose regimen of COVID-19 mRNA-based vaccine in lung transplant recipients.

BACKGROUND: Previous studies have reported that lung transplant recipients (LTR) develop a poor response to two doses of COVID-19 vaccine, but data regarding the third dose are lacking. We investigated the antibody response after three doses of mRNA vaccine in LTR and its predictive factors. METHODS: A total of 136 LTR, including 10 LTR previously infected and 126 COVID-19-naive LTR, were followed during and after three doses of mRNA vaccine. We retrospectively measured anti-receptor-binding domain (RBD) IgG response and neutralizing antibodies. In a posthoc analysis, we used a multivariate logistic regression model to assess the association between vaccine response and patient characteristics, including viral DNA load (VL) of the ubiquitous Torque teno virus (TTV) (optimal cut-off set by ROC curve analysis), which reflects the overall immunosuppression. RESULTS: After 3 doses, 47/126 (37.3%) COVID-19-naive LTR had positive anti-RBD IgG (responders) and 14/126 (11.1%) had antibody titers above 264 Binding Antibody Units/mL. None neutralized the omicron variant versus 7 of the 10 previously infected LTR. Nonresponse was associated with TTV VL ≥6.2 log10 copies/mL before vaccination (Odds Ratio (OR) = 17.87, 95% confidence interval (CI95) = 3.02-105.72), mycophenolate treatment (OR = 4.73, CI95 = 1.46-15.34) and BNT162b2 (n = 34; vs mRNA-1273, n = 101) vaccine (OR = 6.72, CI95 = 1.75-25.92). In second dose non-responders, TTV VL ≥6.2 or <3.2 log10 copies/mL before the third dose was associated with low (0/19) and high (9/10) rates of seroconversion. CONCLUSION: COVID-19-naive LTR respond poorly to three doses of mRNA vaccine, especially those with high TTV VL. Future studies could further evaluate this biomarker as a guide for vaccine strategies.

Atypical Unilateral SARS-CoV-2 Pneumonia in a Single Lung Re-Transplanted Patient: A Case Report.

BACKGROUND: Since December 2019, the SARS-CoV-2 pandemic significantly has impacted the medical community. When infected with SARS-CoV-2, most of the patients developed bilateral pneumonia. We have herein presented the atypical case of a patient who developed unilateral SARS-CoV-2 pneumonia, affecting only the second lung allograft re-transplanted (re-LTX). CASE PRESENTATION: A SARS-CoV-2 infection occurred in a 2-dose vaccinated patient with LTx with a history of second unilateral lung transplantation performed after an end-stage bronchiolitis obliterans syndrome. The first symptoms started with a flu-like syndrome, and the patient's clinical condition worsened with nonsevere acute respiratory failure requiring conventional oxygen therapy. Treatment consisted in administrating specific anti-SARS-CoV-2 monoclonal antibodies along with probabilistic antibiotherapy, anticoagulation, and steroids. On day 7, the patient was discharged from hospital. We aimed to assess this atypical unilateral pneumonia based on different explorations. A ventilation scintigraphy showed a severe ventilation decrease owing to end-stage bronchiolitis obliterans syndrome within the left first allograft, which may be associated with asymmetrical virus diffusion between the 2 lungs. We did not identify any other relevant differences with respect to the 2 donors' clinical characteristics. Using specific immunohistochemistry staining against angiotensin converting enzyme-2 receptor, the main known receptor for SARS-CoV-2 binding on airway epithelial cells, no staining difference was observed between the 2 lung biopsies that were collected at re-LTx from each lung. CONCLUSIONS: With the present case report, we aimed to highlight how this kind of unusual presentation may be caused by the difference of ventilation between the 2 lungs.

Case Report: Evolution of Humoral and Cellular Immunity in Two COVID-19 Breakthrough Infections After BNT162b2 Vaccine.

Background: SARS-CoV-2 breakthrough infections after complete vaccination are increasing whereas their determinants remain uncharacterized. Methods: We analyzed two cases of post-vaccination SARS-CoV-2 infections by α and ß variants, respectively. For each participant both humoral (binding and neutralizing antibodies) and cellular (activation markers and cytokine expression) immune responses were characterized longitudinally. Results: The first participant (P1) was infected by an α variant and displayed an extended and short period of viral excretion and symptom. Analysis of cellular and humoral response 72 h post-symptom onset revealed that P1 failed at developing neutralizing antibodies and a potent CD4 memory response (lack of SARS-CoV-2 specific CD4+IL-2+ cells) and CD8 effector response (CD8+IFNγ+ cells). The second participant (P2) developed post-vaccination SARS-CoV-2 infection by a ß variant, associated with a short period of viral excretion and symptoms. Despite displaying initially high levels and polyfunctional T cell responses, P2 lacked initial ß-directed neutralizing antibodies. Both participants developed and/or increased their neutralization activity and cellular responses against all variants, namely, ß and δ variants that lasts up to 3 months after breakthrough infection. Conclusions: An analysis of cellular and humoral response suggests two possible mechanisms of breakthrough infection: a poor immune response to vaccine and viral evasion to neutralizing antibodies.

Combining predictive markers for severe COVID-19: Torquetenovirus DNA load and SARS-CoV-2 RNAemia.

RATIONALE/OBJECTIVES: SARS-CoV-2 is the cause of worldwide COVID-19, which severity has been linked to the immune and inflammatory response. Here, we investigate Torquetenovirus (TTV) DNA load - a marker reflecting the intensity of the overall immune response - as well as SARS-CoV-2 RNAemia and IgM/IgG antibodies in COVID-19-positive patients. METHODS: Two hundred and fifteen COVID-19-positive patients were enrolled, including 87 severe cases and 128 mild-moderate cases. SARS-CoV-2 RNAemia and IgM/IgG antibodies, as well as TTV DNA loads, were measured on longitudinal plasma samples. RESULTS: The rate of severe cases was higher in patients with low TTV DNA load in plasma considering a threshold of 700 copies/mL. In severe patients, SARS-CoV-2 RNAemia positivity rates were higher than those in mild-moderate cases at any timepoint. When combined, TTV DNA load and SARS-CoV-2 RNAemia allowed to predict the outcome of COVID-19 infection, with a higher risk (HR=12.4) of ICU admission in patients with low TTV DNA load and positive SARS-CoV-2 RNAemia. CONCLUSIONS: TTV DNA load and SARS-CoV-2 RNAemia may be effective, non-invasive markers reflecting disease severity and poor outcome that could be conveniently measured in a clinical laboratory setting, as soon as COVID-19 diagnosis is made.

Infection or a third dose of mRNA vaccine elicits neutralizing antibody responses against SARS-CoV-2 in kidney transplant recipients.

Transplant recipients, who receive therapeutic immunosuppression to prevent graft rejection, are characterized by high coronavirus disease 2019 (COVID-19)-related mortality and defective response to vaccines. We observed that previous infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), but not the standard two-dose regimen of vaccination, provided protection against symptomatic COVID-19 in kidney transplant recipients. We therefore compared the cellular and humoral immune responses of these two groups of patients. Neutralizing anti-receptor-binding domain (RBD) immunoglobulin G (IgG) antibodies were identified as the primary correlate of protection for transplant recipients. Analysis of virus-specific B and T cell responses suggested that the generation of neutralizing anti-RBD IgG may have depended on cognate T-B cell interactions that took place in germinal center, potentially acting as a limiting checkpoint. High-dose mycophenolate mofetil, an immunosuppressive drug, was associated with fewer antigen-specific B and T follicular helper (TFH) cells after vaccination; this was not observed in patients recently infected with SARS-CoV-2. Last, we observed that, in two independent prospective cohorts, administration of a third dose of SARS-CoV-2 mRNA vaccine restored neutralizing titers of anti-RBD IgG in about 40% of individuals who had not previously responded to two doses of vaccine. Together, these findings suggest that a third dose of SARS-CoV-2 mRNA vaccine improves the RBD-specific responses of transplant patients treated with immunosuppressive drugs.

COVID-19 exposure in SARS-CoV-2-seropositive hospital staff members during the first pandemic wave at Strasbourg University Hospital, France.

OBJECTIVES: Strasbourg University Hospital faced an important COVID-19 first wave from early March 2020. We performed a longitudinal prospective cohort study to describe clinical and virological data, exposure history to COVID-19, and adherence to strict hygiene standards during the first pandemic wave in 1497 workers undergoing a SARS-CoV-2 serological test at our hospital, with a follow up of serology result three months later. PATIENTS AND METHODS: A total of 1497 patients were enrolled from April 6 to May 7, 2020. Antibody response to SARS-CoV-2 was measured, and COVID-19 exposure routes were analyzed according to SARS-CoV-2 serological status. RESULTS: A total of 515 patients (34.4%) were seropositive, mainly medical students (13.2%) and assistant nurses (12.0%). A history of COVID-19 exposure in a professional and/or private setting was mentioned by 83.1% of seropositive subjects (P<0.05; odds ratio [OR]: 2.5; 95% confidence interval [CI]: 1.8-3.4). COVID-19 exposure factors associated with seropositive status were non-professional exposure (OR: 1.9, 95% CI: 1.3-2.7), especially outside the immediate family circle (OR: 2.2, 95% CI: 1.2-3.9) and contact with a COVID-19 patient (OR: 1.6; 95% CI: 1.1-2.2). Among professionally exposed workers, systematic adherence to strict hygiene standards was well observed, except for the use of a surgical mask (P<0.05, OR: 1.9, 95% CI: 1.3-2.8). Of those who reported occasionally or never wearing a surgical mask, nurses (25.7%), assistant nurses (16.2%), and medical students (11.7%) were predominant. CONCLUSION: Infection of staff members during the first pandemic wave in our hospital occurred after both professional and private COVID-19 exposure, underlining the importance of continuous training in strict hygiene standards.

Evolution of antibody responses up to 13 months after SARS-CoV-2 infection and risk of reinfection.

BACKGROUND: Assessment of the kinetics of SARS-CoV-2 antibodies is essential in predicting risk of reinfection and durability of vaccine protection. METHODS: This is a prospective, monocentric, longitudinal, cohort clinical study. Healthcare workers (HCW) from Strasbourg University Hospital were enrolled between April 6th and May 7th, 2020 and followed up to 422 days. Serial serum samples were tested for antibodies against the Receptor Binding Domain (RBD) of the spike protein and nucleocapsid protein (N) to characterize the kinetics of SARS-CoV-2 antibodies and the incidence of reinfection. Live-neutralization assays were performed for a subset of samples before and after vaccination to analyze sensitivity to SARS-CoV-2 variants. FINDINGS: A total of 4290 samples from 393 convalescent COVID-19 and 916 COVID-19 negative individuals were analyzed. In convalescent individuals, SARS-CoV-2 antibodies followed a triphasic kinetic model with half-lives at month (M) 11-13 of 283 days (95% CI 231-349) for anti-N and 725 days (95% CI 623-921) for anti-RBD IgG, which stabilized at a median of 1.54 log BAU/mL (95% CI 1.42-1.67). The incidence of SARS-CoV-2 infections was 12.22 and 0.40 per 100 person-years in COVID-19-negative and COVID-19-positive HCW, respectively, indicating a relative reduction in the incidence of SARS-CoV-2 reinfection of 96.7%. Live-virus neutralization assay revealed that after one year, variants D614G and B.1.1.7, but less so B.1.351, were sensitive to anti-RBD antibodies at 1.4 log BAU/mL, while IgG ≥ 2.0 log BAU/mL strongly neutralized all three variants. These latter anti-RBD IgG titers were reached by all vaccinated HCW regardless of pre-vaccination IgG levels and type of vaccine. INTERPRETATION: Our study demonstrates a long-term persistence of anti-RBD antibodies that may reduce risk of reinfection. By significantly increasing cross-neutralizing antibody titers, a single-dose vaccination strengthens protection against variants. FUN1DING: None.

Refining "Long-COVID" by a Prospective Multimodal Evaluation of Patients with Long-Term Symptoms Attributed to SARS-CoV-2 Infection.

INTRODUCTION: COVID-19 long-haulers, also decribed as having "long-COVID" or post-acute COVID-19 syndrome, represent 10% of COVID-19 patients and remain understudied. METHODS: In this prospective study, we recruited 30 consecutive patients seeking medical help for persistent symptoms (> 30 days) attributed to COVID-19. All reported a viral illness compatible with COVID-19. The patients underwent a multi-modal evaluation, including clinical, psychologic, virologic and specific immunologic assays and were followed longitudinally. A group of 17 convalescent COVID-19 individuals without persistent symptoms were included as a comparison group. RESULTS: The median age was 40 [interquartile range: 35-54] years and 18 (60%) were female. At a median time of 152 [102-164] days after symptom onset, fever, cough and dyspnea were less frequently reported compared with the initial presentation, but paresthesia and burning pain emerged in 18 (60%) and 13 (43%) patients, respectively. The clinical examination was unremarkable in all patients, although the median fatigue and pain visual analog scales were 7 [5-8] and 5 [2-6], respectively. Extensive biologic studies were unremarkable, and multiplex cytokines and ultra-sensitive interferon-α2 measurements were similar between long-haulers and convalescent COVID-19 individuals without persistent symptoms. Using SARS-CoV-2 serology and IFN-γ ELISPOT, we found evidence of a previous SARS-CoV-2 infection in 50% (15/30) of patients, with evidence of a lack of immune response, or a waning immune response, in two patients. Finally, psychiatric evaluation showed that 11 (36.7%), 13 (43.3%) and 9 (30%) patients had a positive screening for anxiety, depression and post-traumatic stress disorder, respectively. CONCLUSIONS: Half of patients seeking medical help for post-acute COVID-19 syndrome lack SARS-CoV-2 immunity. The presence of SARS-CoV-2 immunity, or not, had no consequence on the clinical or biologic characteristics of post-acute COVID-19 syndrome patients, all of whom reported severe fatigue, altered quality of life and psychologic distress.

Reduced sensitivity of SARS-CoV-2 variant Delta to antibody neutralization.

The SARS-CoV-2 B.1.617 lineage was identified in October 2020 in India1-5. Since then, it has become dominant in some regions of India and in the UK, and has spread to many other countries6. The lineage includes three main subtypes (B1.617.1, B.1.617.2 and B.1.617.3), which contain diverse mutations in the N-terminal domain (NTD) and the receptor-binding domain (RBD) of the SARS-CoV-2 spike protein that may increase the immune evasion potential of these variants. B.1.617.2-also termed the Delta variant-is believed to spread faster than other variants. Here we isolated an infectious strain of the Delta variant from an individual with COVID-19 who had returned to France from India. We examined the sensitivity of this strain to monoclonal antibodies and to antibodies present in sera from individuals who had recovered from COVID-19 (hereafter referred to as convalescent individuals) or who had received a COVID-19 vaccine, and then compared this strain with other strains of SARS-CoV-2. The Delta variant was resistant to neutralization by some anti-NTD and anti-RBD monoclonal antibodies, including bamlanivimab, and these antibodies showed impaired binding to the spike protein. Sera collected from convalescent individuals up to 12 months after the onset of symptoms were fourfold less potent against the Delta variant relative to the Alpha variant (B.1.1.7). Sera from individuals who had received one dose of the Pfizer or the AstraZeneca vaccine had a barely discernible inhibitory effect on the Delta variant. Administration of two doses of the vaccine generated a neutralizing response in 95% of individuals, with titres three- to fivefold lower against the Delta variant than against the Alpha variant. Thus, the spread of the Delta variant is associated with an escape from antibodies that target non-RBD and RBD epitopes of the spike protein.

Sex Differences in the Evolution of Neutralizing Antibodies to Severe Acute Respiratory Syndrome Coronavirus 2.

We measured anti-spike (S), nucleoprotein (N), and neutralizing antibodies in sera from 308 healthcare workers with a positive reverse-transcription quantitative polymerase chain reaction result for severe acute respiratory syndrome coronavirus 2 and with mild disease, collected at 2 timepoints up to 6 months after symptom onset. At month 1, anti-S and -N antibody levels were higher in male participants aged >50 years and participants with a body mass index (BMI) >25 kg/m2. At months 3-6, anti-S and anti-N antibodies were detected in 99% and 59% of individuals, respectively. Anti-S antibodies and neutralizing antibodies declined faster in men than in women, independent of age and BMI, suggesting an association of sex with evolution of the humoral response.

Intravenous immunoglobulin as a preventive strategy against BK virus viremia and BKV-associated nephropathy in kidney transplant recipients-Results from a proof-of-concept study.

BK virus (BKV) replication occurs frequently in kidney transplant recipients (KTR), potentially leading to BKV-associated nephropathy (BKVAN) and graft loss. Patients with high titers of BKV-neutralizing antibodies (NAbs) are protected against BKV replication, and intravenous immunoglobulin (IVIg) infusion can increase NAb titers. We investigated whether early IVIg administration prevents BKV replication in patients with low NAb titers (<4 log10 against the BKV-specific genotype). Based on NAb titers on the day of transplantation, KTR followed in the Strasbourg University Hospital (n = 174) were retrospectively divided into the following 3 risk categories for BKV replication: (1) patients with low NAb titers ("high-risk") who received IVIg for the first 3 posttransplant months (n = 44), (2) patients with low NAb titers ("high-risk") who did not undergo IVIg treatment (n = 41), and (3) patients with high NAb titers ("low-risk") who did not receive IVIg (n = 89). At 12 posttransplant months, the incidence of BKV viremia in the high-risk group treated with IVIg (6.8%) was similar to that observed in the low-risk group (10.1%) and markedly lower than that of the untreated high-risk group (36.6%; P < .001). Similar results were observed with regard to BKVAN. We conclude that IVIg may be a valuable strategy for preventing BKV replication.

Intrafamilial Exposure to SARS-CoV-2 Associated with Cellular Immune Response without Seroconversion, France.

We investigated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibodies and T-cell responses against SARS-CoV-2 and human coronavirus (HCoV) 229E and OC43 in 11 SARS-CoV-2 serodiscordant couples in Strausbourg, France, in which 1 partner had evidence of mild coronavirus disease (COVID-19) and in 10 unexposed healthy controls. Patients with confirmed COVID-19 were considered index patients and their partners close contacts. All index patients displayed positive SARS-CoV-2-specific antibody and T-cell responses that lasted up to 102 days after symptom onset. All contacts remained seronegative for SARS-CoV-2; however, 6 reported COVID-19 symptoms within a median of 7 days after their partners, and 4 of those showed a positive SARS-CoV-2-specific T-cell response against 3 or 4 SARS-CoV-2 antigens that lasted up to 93 days after symptom onset. The 11 couples and controls displayed positive T-cell responses against HCoV-229E or HCoV-OC43. These data suggest that exposure to SARS-CoV-2 can induce virus-specific T-cell responses without seroconversion.

Inadequate Immune Humoral Response against JC Virus in Progressive Multifocal Leukoencephalopathy Non-Survivors.

JC virus (JCV) causes progressive multifocal leukoencephalopathy (PML) in immunosuppressed patients. There is currently no effective specific antiviral treatment and PML management relies on immune restoration. Prognosis markers are crucially needed in this disease because of its high mortality rate. In this work, we investigated the compartmentalization of JCV strains as well as the humoral neutralizing response in various matrices to further understand the pathophysiology of PML and define markers of survival. Four patients were included, of which three died in the few months following PML onset. Cerebrospinal fluid (CSF) viral loads were the highest, with plasma samples having lower viral loads and urine samples being mostly negative. Whether at PML onset or during follow-up, neutralizing antibody (NAb) titers directed against the same autologous strain (genotype or mutant) were the highest in plasma, with CSF titers being on average 430-fold lower and urine titers 500-fold lower at the same timepoint. Plasma NAb titers against autologous genotype or mutant were lower in non-survivor patients, though no neutralization "blind spot" was observed. The surviving patient was followed up until nine months after PML onset and presented, at that time, an increase in neutralizing titers, from 38-fold against the autologous genotype to around 200-fold against PML mutants. Our results suggest that patients' humoral neutralizing response against their autologous strain may play a role in PML outcome, with survivors developing high NAb titers in both plasma and CSF.