Correlation of a commercial platform's results with post-vaccination SARS-CoV-2 neutralizing antibody response and clinical host factors

INTRODUCTION

The objective of this study was to describe the correlation between the commercially available assay for anti-S1/RBD IgG and protective serum neutralizing antibodies (nAb) against SARS-CoV-2 in an adult population after SARS-CoV-2 vaccination, and determine if clinical variables impact this correlation.

METHODS

We measured IgG anti-S1/RBD using the IgG-II CMIA assay and nAb IC50 values against SARS-CoV-2 WA-1 in sera serially collected post-mRNA vaccination in veterans and healthcare workers of the Veterans Affairs Connecticut Healthcare System (VACHS) between December 2020 and January 2022. The correlation between IgG and IC50 was measured using Pearson correlation. Clinical variables (age, sex, race, ethnicity, prior COVID infection defined by RT-PCR, history of malignancy, estimated glomerular filtration rate (GFR calculated using CKD-EPI equation) were collected by manual chart review. The impact of these clinical variables on the IgG-nAb correlation was analyzed first with univariable regression. Variables with a significance of p < 0.15 were analyzed with forward stepwise regression analysis.

RESULTS

From 127 sera samples in 100 unique subjects (age 20-93 years; mean 63.83; SD 15.63; 29% female; 67% White), we found a robust correlation between IgG anti-S1/RBD and nAb IC50 (R2 = 0.83, R2adj = 0.70, p < 0.0001). Race, ethnicity, and a history of malignancy were not significant on univariable analysis. GFR (p < 0.05) and prior COVID infection (p < 0.001) had a significant impact on the correlation between IgG anti-S1/RBD and nAb IC50. Age (p = 0.06) and sex (p = 0.07) trended towards significance on univariable analysis, but were not significant on multivariable regression.

CONCLUSIONS

There was a strong correlation between IgG anti-S1/RBD and nAb IC50 after SARS-CoV-2 vaccination. Clinical comorbidities, such as prior COVID infection and renal function, impacted this correlation. These results may assist the prediction of post-vaccination immune protection in clinical settings using cost-effective commercial platforms.

Prevalence of and risk factors for vertebral fracture and low bone mineral density among Peruvian women aging with HIV

Osteoporosis and fracture risk among women with HIV in Latin America is understudied. In a sample of Peruvian women with and without HIV, women with HIV had lower femoral neck and total hip BMD and a higher proportion of vertebral fractures. Important treatment gaps were identified across both groups.

PURPOSE

Studies have shown that patients with HIV are at increased risk for bone loss and fracture due to a combination of host, viral, and antiretroviral therapy (ART)-related factors. We aimed to explore the prevalence of vertebral fracture (VF) and low bone mineral density (BMD) among women aging with HIV in Peru and identify risk factors for osteoporosis and fracture in this population.

METHODS

We enrolled women living with and without HIV aged ≥40 years between 2019 and 2020. Participants completed a survey and obtained dual X-ray absorptiometry (DXA) test to assess BMD at the lumbar spine (LS), femoral neck (FN), and total hip (TH). A subset of patients also obtained lateral thoracolumbar X-rays. Presence of VF was determined using the Genant semiquantitative method. Regression analyses were used to model associations between key risk factors and BMD.

RESULTS

104 women living with HIV and 212 women living without HIV were enrolled with a mean age of 52.4±8.2 and 56.4±8.8 years (p < 0.001). Among postmenopausal women (257/316, 81.3%), 26.3% of women living with HIV and 25.9% of those without HIV had osteoporosis. Among the 88 women living with HIV and 178 women living without HIV who obtained thoracolumbar X-rays, 12.5% and 6.2%, respectively, had at least one VF. Based on DXA and the FRAX score, 22/104 women living with HIV met criteria for osteoporosis treatment according to national guidelines; however, none were on treatment. Propensity score matching revealed that women living with HIV had 0.032 g/cm2 lower FN BMD (p = 0.012) and 0.034 g/cm2 lower TH BMD (p = 0.041) compared to women without HIV.

CONCLUSION

In this study, women living with HIV on long-standing ART had increased VF prevalence compared to the slightly older group of women without HIV. Age and BMI were independent predictors for BMD at the lumbar spine, hip, and femoral neck among women living with HIV, and there was a treatment gap among women who met criteria for osteoporosis treatment. Larger studies are needed in this region to identify individuals at risk for fracture and to inform prevention guidelines.

Serum Neutralizing Antibody Titers 12 Months After Coronavirus Disease 2019 Messenger RNA Vaccination: Correlation to Clinical Variables in an Adult, US Population

BACKGROUND

We studied whether comorbid conditions affect strength and duration of immune responses after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) messenger RNA vaccination in a US-based, adult population.

METHODS

Sera (before and after BNT162b2 vaccination) were tested serially up to 12 months after 2 doses of vaccine for SARS-CoV-2-anti-Spike neutralizing capacity by pseudotyping assay in 124 individuals; neutralizing titers were correlated to clinical variables with multivariate regression. Postbooster (third dose) effect was measured at 1 and 3 months in 72 and 88 subjects, respectively.

RESULTS

After completion of primary vaccine series, neutralizing antibody half maximal inhibitory concentration (IC50) values were high at 1 month (14-fold increase from prevaccination), declined at 6 months (3.3-fold increase), and increased at 1 month postbooster (41.5-fold increase). Three months postbooster, IC50 decreased in coronavirus disease (COVID)-naïve individuals (18-fold increase) and increased in prior COVID 2019 (COVID-19+) individuals (132-fold increase). Age >65 years (β = -0.94, P = .001) and malignancy (β = -0.88, P = .002) reduced strength of response at 1 month. Both neutralization strength and durability at 6 months, respectively, were negatively affected by end-stage renal disease ([β = -1.10, P = .004]; [β = -0.66, P = .014]), diabetes mellitus ([β = -0.57, P = .032]; [β = -0.44, P = .028]), and systemic steroid use ([β = -0.066, P = .032]; [β = -0.55, P = .037]). Postbooster IC50 was robust against WA-1 and B.1.617.2. Postbooster neutralization increased with prior COVID-19 (β = 2.9, P < .0001), and malignancy reduced neutralization response (β = -0.68, P = .03), regardless of infection status.

CONCLUSIONS

Multiple clinical factors affect the strength and duration of neutralization response after primary series vaccination, but not the postbooster dose strength. Malignancy was associated with lower booster-dose response regardless of prior COVID infection, suggesting a need for clinically guided vaccine regimens.

Clinical Variables Correlate with Serum Neutralizing Antibody Titers after COVID-19 mRNA Vaccination in an Adult, US-based Population

Background

We studied whether comorbid conditions impact strength and duration of immune responses after SARS-CoV-2 mRNA vaccination in a US-based, adult population.

Methods

Sera (pre-and-post-BNT162b2 vaccination) were tested serially up to 12 months after two doses of vaccine for SARS-CoV-2-anti-Spike neutralizing capacity by pseudotyping assay in 124 individuals; neutralizing titers were correlated to clinical variables with multivariate regression. Post-booster (third dose) effect was measured at 1 and 3 months in 72 and 88 subjects respectively.

Results

After completion of primary vaccine series, neutralizing antibody IC50 values were high at one month (14-fold increase from pre-vaccination), declined at six months (3.3-fold increase), and increased at one month post-booster (41.5-fold increase). Three months post-booster, IC50 decreased in COVID-naïve individuals (18-fold increase) and increased in prior COVID-19+ individuals (132-fold increase). Age >65 years (β=-0.94, p=0.001) and malignancy (β=-0.88, p=0.002) reduced strength of response at 1 month. Both strength and durability of response at 6 months, respectively, were negatively impacted by end-stage renal disease [(β=-1.10, p=0.004); (β=-0.66, p=0.014)], diabetes mellitus [(β=-0.57, p=0.032); (β=-0.44, p=0.028)], and systemic steroid use [(β=-0.066, p=0.032); (β=-0.55, p=0.037)]. Post-booster IC50 was robust against WA-1 and B.1.617.2, but the immune response decreased with malignancy (β =-0.68, p=0.03) and increased with prior COVID-19 (p-value < 0.0001).

Conclusion

Multiple clinical factors impact the strength and duration of neutralization response post-primary series vaccination, but not the post-booster dose strength. Prior COVID-19 infection enhances the booster-dose response except in individuals with malignancy, suggesting a need for clinically guiding vaccine dosing regimens.

Summary

Multiple clinical factors impact the strength and duration of neutralization response post-primary series vaccination. All subjects, irrespective of prior COVID infection, benefited from a third dose. Malignancy decreased response following third dose, suggesting the importance of clinically guided vaccine regimens.

Gomori Methenamine Silver Stain on Bronchoalveolar Lavage Fluid Is Poorly Sensitive for Diagnosis of Pneumocystis jiroveci Pneumonia in HIV-Negative Immunocompromised Patients and May Lead to Missed or Delayed Diagnoses

CONTEXT.—

Direct visualization of Pneumocystis jiroveci organisms, using Gomori methenamine silver (GMS) staining in bronchoalveolar lavage fluid (BAL), is a historical gold standard that has been widely used for the diagnosis of P jiroveci pneumonia (PJP). However, the stain may be less sensitive in human immunodeficiency virus (HIV)-negative immunocompromised patients owing to a lower burden of organisms.

OBJECTIVES.—

To assess the sensitivity of the GMS stain on BAL fluid for the diagnosis of PJP in HIV-negative immunocompromised patients as compared to HIV-positive patients.

DESIGN.—

We conducted a retrospective review from 2012 to 2018 to identify immunocompromised patients (≥18 years old) who underwent bronchoscopy with BAL GMS staining for the diagnosis of PJP. To assess for sensitivity, we sought to identify BAL GMS-positive cases and BAL GMS-negative cases of PJP. The BAL GMS-negative cases were categorized into proven and probable PJP.

RESULTS.—

We identified 45 adult immunocompromised patients with proven and probable PJP, including 24 HIV-negative (11 BAL GMS-positive and 13 BAL GMS-negative) and 21 HIV-positive cases (all were BAL GMS-positive). The sensitivity of BAL GMS for the diagnosis of PJP in HIV-negative immunocompromised patients was 11 of 24 (46%) versus 21 of 21 (100%) in HIV-positive patients (CD4: median, 10 cells/mL; range, 3-300 cells/mL). Delayed or missed diagnoses were seen in 3 cases of BAL GMS-negative PJP. Re-examination of BAL GMS slides showed rare P jiroveci cysts in 1 case.

CONCLUSIONS.—

BAL GMS has poor sensitivity for PJP in HIV-negative immunocompromised patients. Using BAL GMS as a sole method for PJP may result in missed or delayed diagnoses in this population.

2566. Diagnosis of Pneumocystis jiroveci Pneumonia in HIV-Negative Immunocompromised Patients: Is the Gomori-Methenamine Silver Stain of Bronchoalveolar Lavage Fluid the Gold Standard or Sub-Standard?

Background

Direct visualization of Pneumocystis jiroveci on bronchoalveolar lavage (BAL) fluid using the Gomori-methenamine-silver (GMS) stain historically has been the mainstay of diagnosis for P. jiroveci pneumonia (PJP), with studies from the early HIV/AIDS era reporting sensitivities of 90–95%. However, the burden of P. jiroveci organisms in BAL fluid is significantly lower in HIV-negative immunocompromised patients compared with HIV-positive patients with PJP, raising concerns that the BAL GMS stain is less sensitive in this population.

Methods

We conducted a retrospective observational study at Yale-New Haven Hospital from 2012 to 2018, using electronic medical record chart reviews, to identify patients who underwent bronchoscopy with BAL GMS stain for the diagnosis of PJP. We collected additional patient factors such as age, sex, HIV status, and immunosuppressed status. For patients with a negative BAL GMS stain, we collected data on other diagnostics, including positive GMS lung biopsies, positive PJP PCR or DFA, and elevated serum (1–3)-β-d-glucan levels. We defined BAL GMS-negative cases as proven or probable based on investigator generated criteria (see Figure 1).

Results

We identified 52 patients with PJP who received a BAL GMS stain, including 28 HIV-positive and 24 HIV-negative cases. Of 24 HIV-negative cases, 11 had BAL GMS-positive PJP and 13 had BAL GMS-negative PJP (9 proven and 4 probable). In the latter group, 6 had hematologic malignancies (HM), 2 had solid-organ transplants (SOT), 1 had hematopoietic stem cell transplant, 2 had SOT plus HM, and 2 received high-dose steroids. Proven diagnoses were made by GMS-positive lung biopsy (n = 6), DFA (n = 2), and PCR (n = 1). Elevated (1–3)-β-d-glucan was observed in 7 of 8 cases (median: >500 pg/mL; range 39 to >500). Three patients developed adverse outcomes (1 readmission due to untreated PJP and 2 treatment delays). BAL GMS sensitivity for HIV-negative patients was 11/24 (46%) vs. 28/28 (100%) in HIV-positive patients.

Conclusion

The sensitivity of BAL GMS for PJP is poor in HIV-negative immunocompromised patients. Missed cases or delayed treatment for PJP may lead to adverse outcomes. In HIV-negative patients with a clinical syndrome compatible with PJP, a negative BAL GMS does not rule out PJP and must be confirmed by supplementary diagnostics.

Disclosures

All authors: No reported disclosures.

The becoming: students' reflections on the process of professional identity formation in medical education

Professional identity formation (PIF) within medical education is the multifaceted, individualized process through which students develop new ways of being in becoming physicians. Personal backgrounds, values, expectations, interests, goals, relationships, and role models can all influence PIF and may account for diversity of both experience and the active constructive process of professional formation. Guided reflection, including reflective writing, has been used to enhance awareness and meaning making within the PIF process for both students and medical educators and to shed light on what aspects of medical education are most constructive for healthy PIF. Student voices about the PIF process now emerging in the literature are often considered and interpreted by medical educators within qualitative studies or in broad theoretical overviews of PIF.In this Commentary, the authors present a chorus of individual student voices from along the medical education trajectory. Medical students (years 1-4) and a first-year resident in pediatrics respond to a variety of questions based on prevalent PIF themes extracted from the literature to reflect on their personal experiences of PIF. Topics queried included pretending in medical education, role of relationships, impact of formal and informal curricula on PIF (valuable aspects as well as suggestions for change), and navigating and developing interprofessional relationships and identities. This work aims to vividly illustrate the diverse and personal forces at play in individual students' PIF processes and to encourage future pedagogic efforts supporting healthy, integrated PIF in medical education.