ABSTRACT
It is important to constantly monitor developments in the preclinical imaging arena of infection. Firstly, novel radiopharmaceuticals with the correct characteristics must be identified to funnel into the clinic. Secondly, it must be evaluated if enough innovative research is being done and adequate resources are geared towards the development of radiopharmaceuticals that could feed into the Nuclear Medicine Clinic in the near future. It is proposed that the ideal infection imaging agent will involve PET combined with CT but more ideally MRI. The radiopharmaceuticals currently presented in preclinical literature have a wide selection of vectors and targets. Ionic formulations of PET-radionuclides such 64CuCl2 and 68GaCl2 are evaluated for bacterial infection imaging. Many small molecule based radiopharmaceuticals are being investigated with the most prominent targets being cell wall synthesis, maltodextrin transport (such as [18F]F-maltotriose), siderophores (bacterial and fungal infections), the folate synthesis pathway (such as [18F]F-PABA) and protein synthesis (radiolabelled puromycin). Mycobacterial specific antibiotics, antifungals and antiviral agents are also under investigation as infection imaging agents. Peptide based radiopharmaceuticals are developed for bacterial, fungal and viral infections. The radiopharmaceutical development could even react quickly enough on a pandemic to develop a SARS-CoV-2 imaging agent in a timely fashion ([64Cu]Cu-NOTA-EK1). New immuno-PET agents for the imaging of viruses have recently been published, specifically for HIV persistence but also for SARS-CoV2. A very promising antifungal immuno-PET agent (hJ5F) is also considered. Future technologies could include the application of aptamers and bacteriophages and even going as far as the design of theranostic infection. Another possibility would be the application of nanobodies for immuno-PET applications. Standardization and optimization of the preclinical evaluation of radiopharmaceuticals could enhance clinical translation and reduce time spent in pursuing less than optimal candidates.
ABSTRACT
Patients with cancer are presumed to be vulnerable to an increased risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and severe clinical outcomes due to the immunocompromised state mediated by their underlying malignancies and therapy. The aim of this study was to estimate the SARS-CoV-2 seroprevalence, following second to fourth waves in solid tumour patients attending the Steve Biko Academic Hospital (SBAH) for diagnosis and treatment of cancer. We used the single-prick COVID-19 IgG/IgM Rapid Test Cassettes to detect SARS-CoV-2 IgG/IgM antibodies in 760 patients with solid tumours who were asymptomatic and who had never tested positive for coronavirus disease 2019 (COVID-19). Out of the 760 patients, 277 were male (36.4%), 483 were female (63.6%), and the mean age was 55 years (range 18−92). The estimated total seroprevalence was 33.2%. The seroprevalence status of the COVID-19 IgG/IgM antibodies rose significantly from the second wave (11.3%) to the third (67.38%) and then the fourth (69.81%) waves with roughly similar counts. A significant number of the seropositive patients were asymptomatic to COVID-19 (96%). There was a higher rate of seropositivity in cancer patients with hypertension (p < 0.05). Patients with breast, gynaecologic, and prostate cancers exhibited increased SARS-CoV-2 seropositivity. Although oncology patients may be susceptible to SARS-CoV-2 infection, our data indicate that these patients remained asymptomatic throughout various waves with an overall COVID-19 IgG/IgM antibody seropositivity of 33.16%, suggesting no risk of severe or fatal cases of COVID-19.