CoVITEST: A Fast and Reliable Method to Monitor Anti-SARS-CoV-2 Specific T Cells From Whole Blood

Cellular and humoral immune responses are essential for COVID-19 recovery and protection against SARS-CoV-2 reinfection. To date, the evaluation of SARS-CoV-2 immune protection has mainly focused on antibody detection, generally disregarding the cellular response, or placing it in a secondary position. This phenomenon may be explained by the complex nature of the assays needed to analyze cellular immunity compared with the technically simple and automated detection of antibodies. Nevertheless, a large body of evidence supports the relevance of the T cell's role in protection against SARS-CoV-2, especially in vulnerable individuals with a weakened immune system (such as the population over 65 and patients with immunodeficiencies). Here we propose to use CoVITEST (Covid19 anti-Viral Immunity based on T cells for Evaluation in a Simple Test), a fast, affordable and accessible in-house assay that, together with a diagnostic matrix, allows us to determine those patients who might be protected with SARS-CoV-2-reactive T cells. The method was established using healthy SARS-CoV-2-naïve donors pre- and post-vaccination (n=30), and further validated with convalescent COVID-19 donors (n=51) in a side-by-side comparison with the gold standard IFN-γ ELISpot. We demonstrated that our CoVITEST presented reliable and comparable results to those obtained with the ELISpot technique in a considerably shorter time (less than 8 hours). In conclusion, we present a simple but reliable assay to determine cellular immunity against SARS-CoV-2 that can be used routinely during this pandemic to monitor the immune status in vulnerable patients and thereby adjust their therapeutic approaches. This method might indeed help to optimize and improve decision-making protocols for re-vaccination against SARS-CoV-2, at least for some population subsets.

What will (and should) be improved in CAR immunotherapy?

Chimeric antigen receptor (CAR) is probably one of the most successful proposals for cancer treatment, especially hematological diseases for which several Advanced Therapies Medicinal Products (ATMP) have been approved worldwide by drug agencies. But, despite this unprecedented success in the oncology and cell/gene therapy fields, there are a lot of aspects that could (and should) be improved in the multiple aspects that involve this complex therapy: from the design of the chimeric molecule to the clinical protocols of use of the engineered T-cells, including even the regulatory rules that they are currently restricting the development of these hopeful therapies. In this chapter, we will try to summarize the main aspects that can (and probably should) be improved for the expansion of immunotherapy with CAR proposals beyond onco-hematology.

Nutritional status of institutionalised elderly in Ecuador

The nutritional status of 111 elderly men and women aged 60 to 99 years in two institutions in the Ecuadorian Andes was evaluated using dietary, anthropometric and biochemical measurements. Mean daily energy intakes of men and women were 1720 and 1650 kcal, respectively (7.2 and 6.9 MJ), corresponding to 1.5 times the calculated basal metabolic rate (BMR). 6% of subjects had intakes less than 1.2 x BMR and 40% less than 1.5 x BMR. Body mass index (BMI) was below 20 kg/m2 in 21% of subjects; 45% were between 20 and 24. Only one subject had a BMI over 29. Intakes of protein, calcium, iron, riboflavin and vitamin C were satisfactory, in contrast to those of zinc, vitamin A, niacin and thiamin. Using sex- and altitude-specific cutoffs for hemoglobin, anemia was observed in 11% of subjects. Nutritional status, evaluated using biochemical indicators, was satisfactory with respect to riboflavin, vitamin A, vitamin E and copper. 14% of subjects had low serum zinc levels and 17% had serum albumin values below 35 g/L. Low physical activity was associated with low energy intake and low serum albumin levels.

UltramicroELISA for measuring tetanus antitoxin in human sera

This article describes a combination of methods--a solid-phase enzyme-linked immunosorbent assay (ELISA) combined with an ultramicroanalytical system (UMAS)--that can be used to measure tetanus antitoxin activity in human sera or plasma. The test, which is rapid and permits analysis of 78 samples of serum per reaction plate with a volume of 10 microL of diluted serum per sample, is proposed as an alternative to the traditional biologic assay in mice based on seroneutralization of a known dose of tetanus toxin. The study reported here compared these two procedures, using them both to evaluate 100 sera from the Clinical Laboratory of the General Calixto García Hospital in Havana, Cuba. The two sets of results showed a high degree of correlation (r = 0.99) when subjected to linear regression analysis (95% CI = 0.985-0.993). These and other findings indicate that the cheap and rapid ultramicroELISA method can perform certain tasks for which the slower and costlier traditional assay is not well suited, such as field evaluation of tetanus toxoid vaccines and identification of hyperimmune plasmas appropriate for use in producing specific antitetanus immunoglobulin.

[Ultramicro-ELISA for measuring tetanus antitoxin in human serum]

A solid-phase enzyme immunoassay (ELISA) for measuring tetanus antitoxin activity in human serum is described; the assay is based on a combination of the indirect method and ultramicro analysis. This rapid test, which has the capacity to analyze 78 blood samples per reagent plate (at a volume of 10 microL of diluted serum per sample), is proposed as an alternative to the traditional mouse bioassay system based on the neutralization of a known dose of tetanus toxin. Results from both tests showed a high correlation in the lineal regression analysis (r = 0.99; CI95%: 0.985 to 0.993). It is recommended that the ultramicro ELISA assay be used in the field to evaluate tetanus toxoid vaccines and to identify hyperimmune plasmas suitable for producing antitetanus immunoglobulin.