Study flowchart.

<p>Study flowchart.</p

Characteristics of the 10 patients negative for HIV-1 blood plasma result and positive for HIV-1 seminal plasma.

<p>3TC, lamivudine; ATV, atazanavir; D4T, stavudine; DDI, didanosine; EFV, efivarenz; FTC, emtricitabine; LPV, lopinavir; RTV, ritonavir; SQV, saquinavir; TDF, tenofovir; ZDV, zidovudine.</p><p>In bold are the antiretroviral with good penetration into genital compartment.</p

Regression analysis and Bland-Altman representation of titer differences in DBS and plasma of HBsAg levels and HBV DNA levels.

<p>(A) Linear regression analysis of HBsAg levels for the 100 matched DBS-plasma pairs analyzed by immunoassay. (B) Bland-Altman analysis was used to determine the agreement between the HBsAg titer by plotting the differences between the two samples against the averages of the two techniques. (C) Linear regression analysis of HBV DNA levels for the 50 matched DBS-plasma pairs analyzed by real-time PCR quantitative assay. (D) Bland-Altman analysis of HBV DNA.</p

HBV Genotype characterization in DBS and plasma samples.

<p>HBV Genotype characterization in DBS and plasma samples.</p

Evaluation of DBS storage relative to titer in HBsAg and anti-HBs tested by immunoassay.

<p>DBS samples were tested after storage at room temperature during 1, 3, 7, and 14 days. Each line represents 5 positive samples (black symbols) and 3 negative samples (white symbols). The dotted line represents the positive cutoff value for each parameter. (A) Evaluation of DBS storage relative to titer in HBsAg (IU/mL). (B) Evaluation of DBS storage relative to titer in anti-HBs (IU/mL).</p

Study design.

<p>Quantification of HBsAg, anti-HBs, and HBV DNA, including characterization of HBV genotype on DBS using commercial kits. This study used DBS paired with plasma as a reference method.</p

S1 Data -

BackgroundIdentifying a specific threshold level of SARS-CoV-2 antibodies that confers protection in immunocompromised patients has been very challenging. The aim was to assess the threshold of 264 binding antibody units (BAU)/ml using four different SARS-CoV-2 antibody assays (Abbott, Beckman, Roche, and Siemens) and to establish a new optimal threshold of protection for each of the four antibody assays.MethodsThis study was performed on data retrieved from 69 individuals, who received at least one dose of the Pfizer/BioNTech BNT162b2 or Moderna COVID-19 vaccine (Spikevax) at the Alphabio Laboratory in Marseille, France (European Hospital, Alphabio–Biogroup). The results were compared to the percent inhibition calculated using a functional surrogate of a standardized virus neutralization test (Genscript).ResultsSamples from 69 patients were analyzed. For a reference cutoff of 264 BAU/ml, assays showed moderate to good overall concordance with Genscript: 87% concordance for Abbott, 78% for Beckman, 75% for Roche, and 88% for Siemens. Overall concordance increased consistently after applying new thresholds, i.e., 148 BAU/ml (Abbott), 48 (Beckman), 559 (Roche), and 270 (Siemens).ConclusionWe suggest specific adjusted thresholds (BAU/ml) for the four commercial antibody assays that are used to assess pre-exposure prophylaxis in immunocompromised patients.</div

Agreement between antibody binding assays and Genscript sVNT positive and negative results according to the reference cutoff (264 BAU/ml).

Agreement between antibody binding assays and Genscript sVNT positive and negative results according to the reference cutoff (264 BAU/ml).</p

Baseline characteristics.

BackgroundIdentifying a specific threshold level of SARS-CoV-2 antibodies that confers protection in immunocompromised patients has been very challenging. The aim was to assess the threshold of 264 binding antibody units (BAU)/ml using four different SARS-CoV-2 antibody assays (Abbott, Beckman, Roche, and Siemens) and to establish a new optimal threshold of protection for each of the four antibody assays.MethodsThis study was performed on data retrieved from 69 individuals, who received at least one dose of the Pfizer/BioNTech BNT162b2 or Moderna COVID-19 vaccine (Spikevax) at the Alphabio Laboratory in Marseille, France (European Hospital, Alphabio–Biogroup). The results were compared to the percent inhibition calculated using a functional surrogate of a standardized virus neutralization test (Genscript).ResultsSamples from 69 patients were analyzed. For a reference cutoff of 264 BAU/ml, assays showed moderate to good overall concordance with Genscript: 87% concordance for Abbott, 78% for Beckman, 75% for Roche, and 88% for Siemens. Overall concordance increased consistently after applying new thresholds, i.e., 148 BAU/ml (Abbott), 48 (Beckman), 559 (Roche), and 270 (Siemens).ConclusionWe suggest specific adjusted thresholds (BAU/ml) for the four commercial antibody assays that are used to assess pre-exposure prophylaxis in immunocompromised patients.</div

Threshold for DNA detection among different sampling types.

<p>Threshold for DNA detection among different sampling types.</p