Theel, Elitza S.

Abstract Background Cytomegalovirus (CMV) causes significant morbidity in solid organ transplant recipients (SOTR). As a lack of immunity predisposes to infection, a laboratory test that measures CMV-specific cell-mediated immunity (CMV CMI) may help guide antiviral prophylaxis, predict relapses and correlate with outcomes. We assessed CMV CMI in CMV D+/R- patients during valganciclovir primary prophylaxis and in CMV viremic SOTRs during antiviral treatment, and correlated the results with post-prophylaxis CMV infection and post-treatment relapse, respectively. Methods CMV CMI was assessed in two groups of SOTRs using the QuantiFERON© CMV interferon-gamma release assay (IGRA), with level >0.2 IU/mL suggestive of immunity. The first group included CMV D+/R- SOTRs who underwent monthly CMV CMI testing during 6 months of valganciclovir prophylaxis. These patients were prospectively followed for CMV episodes for 1 year post transplant. The second group included SOTRs with CMV viremia or disease, who underwent CMV CMI testing at time of CMV diagnosis and at various time points during antiviral treatment. These patients were prospectively followed for CMV relapse for 1 year post-primary CMV episode. Standard definitions were used to define CMV infection and disease. Results In the primary prophylaxis cohort, 24 CMV mismatched (D+/R-) SOTRs were enrolled. Only 1 patient (4.2%) demonstrated a CMV CMI >0.2 IU/mL by the end of prophylaxis; this patient did not develop CMV disease. Four (16.6%) patients developed post-prophylaxis CMV infection, none of which had CMV CMI >0.2 IU/ml. In the post-treatment cohort, 20 CMV viremic SOTRs were enrolled, including 12 D+/R- (60%). Eighteen (90%) had CMV CMI levels >0.2 IU/mL by end of treatment and none developed CMV relapse. In contrast, the single patient who relapsed after treatment had a CMV CMI response < 0.2 IU/ml (p=0.05). Conclusion CMV D+/R- SOTRs are unlikely to develop CMV CMI during valganciclovir prophylaxis. Thus, the utility of CMV CMI for risk stratification of post-prophylaxis CMV infection in CMV D+/R- SOTRs is questionable. Conversely, CMV CMI testing may potentially be a useful marker of CMV relapse risk after treatment and guide the role of secondary antiviral prophylaxis. Disclosures Elitza Theel, PhD, D(ABMM), Euroimmun US: Advisor/Consultant|Oxford Immunotech: Advisor/Consultant|Roche Diagnostics: Advisor/Consultant|Serimmune Inc: Advisor/Consultant Raymund R. Razonable, MD, American Society of Transplantation: Board Member|gilead: Grant/Research Support|novartis: DSMB|regeneron: Grant/Research Support|Roche: Grant/Research Support.

The detection of antibodies against Histoplasma capsulatum remains a frequently relied-on approach to diagnose histoplasmosis. We retrospectively assessed the performances of complement fixation (CF) and immunodiffusion (ID) assays for anti- Histoplasma antibody detection in patients with culture-confirmed histoplasmosis at Mayo Clinic (Rochester, MN) over a 10-year period (2011 to 2020).

COVID-19 convalescent plasma (CCP) was one of the first therapeutic options available for the treatment of SARS-CoV-2 infections and continues to be used selectively for immunosuppressed patients. Given the emergence of novel SARS-CoV-2 variants which are resistant to treatment with available monoclonal antibody (MAb) therapy, CCP remains an important therapeutic consideration.

AbstractIntroductionTo assess the risk for COVID‐19 of police officers, we are studying the seroprevalence in a cohort. The baseline cross‐sectional investigation was performed before a vaccination campaign in January/February 2021, and demonstrated a seroprevalence of 12.9%. Here, we demonstrate serosurveillance results after a vaccination campaign.MethodsThe cohort consists of 1022 study participants. The 3‐ and 6‐month follow‐up visits were performed in April/May and September 2021. Data on infection and vaccination rates were obtained via measuring antibodies to the nucleocapsid protein and spike protein and online questionnaires.ResultsThe mean age of the population was 41 (SD 8.8) years, 72% were male and 76% had no comorbidity. Seroconversion was identified in 1.05% of the study population at the 3‐month visit and in 0.73% at the 6‐month visit, resulting in an infection rate of 1.8% over a time period of 6 months. In comparison, the infection rate in the general population over the same time period was higher (3.18%, p = .018). At the 6‐month visit, 77.8% of participants reported being vaccinated once and 70.5% twice; 81% had an anti‐S antibody titer of >250 U/ml and 87.1% of ≥2 U/ml. No significant association between infection and job role within the department, working region, or years of experience in the job was found. Anti‐spike antibody titers of vaccinated study participants showed a calculated decreasing trend 150–200 days after the second vaccine dose.ConclusionThese data confirm the value of the vaccination campaign in an exposed group other than healthcare professionals.

Modified two-tiered testing (MTTT) algorithms for Lyme disease (LD), which involve the sequential use of orthogonal enzyme immunoassays (EIAs) without immunoblotting, are acceptable alternatives to standard two-tiered testing (STTT; EIA followed by immunoblots) provided the EIAs have been FDA-cleared for this intended use. We evaluated four Zeus Scientific LD EIAs used in two distinct MTTT algorithms for FDA review.