Detection of infliximab, adalimumab, and anti-drug antibodies: Development and validation of new monotest, automated assays on multiparametric instrument

Objective

To convert manual ELISA kits to fully automated immunoassays that quantify serum drug levels and anti-drug antibodies levels of infliximab and adalimumab (CHORUS Promonitor kits).

Desing and methods

CHORUS Promonitor INFLIXIMAB, CHORUS Promonitor ADALIMUMAB, CHORUS Promonitor ANTI-INFLIXIMAB, and CHORUS Promonitor ANTI-ADALIMUMAB kits were compared with the corresponding Promonitor kits to determine sensitivity and specificity of the assays. For the automated assays, the entire procedure -from samples dilution to final readouts-was performed by CHORUS TRIO instrument (DIESSE, Italy). Residual human serum samples from clinical laboratory investigations and samples resulting from the addition of specific drugs (IFX or ADL) or anti-drug antibodies (anti-IFX or anti-ADL) were used for the characterization and validation of the tests.

Results

CHORUS Promonitor kits showed an excellent agreement (Cohen's coefficient = 1) with the Promonitor kits and were linear within predefined ranges. All assays were accurate and repeatable, as an acceptable variability were observed within runs, between runs, lots, and instruments. No difference in detecting the reference drug or biosimilars emerged.

Conclusion

During preclinical development, these kits resulted as sensitive, specific, accurate, and able to quantify either the reference drug or the corresponding biosimilars. All these features support their use in clinical practice for therapeutic drug monitoring of patients with inflammatory diseases under treatment with IFX or ADL.

Validation, performance, and reliability of two automated tests for vitamin B12 and folate assay

Background

Deficiency of Vitamin B12 and folate may determine hematological, neurological, and metabolic alterations; therefore, an accurate quantification of their serum levels is required, especially in the presence of symptoms that might suggest a deficiency. CHORUS VIT B12 and CHORUS FOLATE are two automated immunoassays, developed to quantify vitamin B12 and folate, respectively, in human serum.

Design and methods

This single-center, non-pharmacological, diagnostic study described the validation and characterization of CHORUS VIT B12 and CHORUS FOLATE, with a specific focus on performance, precision, and reliability. For each assay, 500 serum samples were analyzed. A comparison between CHORUS assays and commercially available kit was also performed.

Results

For CHORUS VIT B12 the lower limit of quantification (LLoQ) was 165.0 pg/mL and the upper LoQ (ULoQ) was 1846.8 pg/mL. The assay was linear within the calibration range (150-2000 pg/mL) and the accuracy was described with the International Standard Vitamin B12, Serum Folate, HOLO TC (NIBSC code: 03/178), with a mean recovery on two lots of 111%. For CHORUS FOLATE (calibration range of 2.0-20.0 ng/mL), LLoQ was 2.0 ng/mL and ULoQ 19.6 ng/mL. The linearity was demonstrated from 2.4 to 20.0 ng/mL; the accuracy was described with the International Standard mentioned above, achieving a mean recovery on three lots of 92%. The lowest and highest values of both CHORUS and COBAS kits were similar and the median values did not significantly vary.

Conclusion

CHORUS VIT B12 and CHORUS FOLATE performed well, accurately, and reliably in quantifying vitamin B12 and folate in human serum.

A quantitative assay for detection of SARS-CoV-2 neutralizing antibodies

OBJECTIVES

Serological assays for SARS-CoV-2 have a critical role not only in diagnosis of COVID-19, but also in assessing the degree and duration of response of specific antibodies against the virus obtained through infection or vaccination. We present the results obtained with a competitive immunoenzymatic method (Chorus SARS-CoV-2 "Neutralizing" Ab) for quantitative determination of total neutralizing anti-S1 SARS-CoV-2 antibodies (IgG, IgM, and IgA) in human serum obtained on a disposable device with the Chorus TRIO instrument using a recombinant strong neutralizing antibody as tracer.

METHODS

A total of 694 sera were evaluated for SARS-CoV-2 neutralizing antibodies: 407 uninfected, 201 symptomatic subjects, 37 post-infection patients, and 49 vaccinated. Sixty-eight of the previous sera were used to compare the Chorus SARS-CoV-2 "Neutralizing" Ab results with those obtained with micro-neutralization of the Alpha and original variants. A set of 74 positive sera for other respiratory infections were analyzed to evaluate the possible cross reaction to SARS-CoV-2 virus.

RESULTS

Of the 694 samples, only 3 had discordant results between micro-neutralization and values measured by Chorus SARS-CoV-2 "Neutralizing" Ab: 1 false negative and 2 false positives. Values of sensitivity and specificity were very high: percent positive agreement (sensitivity) 99.6% (95% CI: 97.7 - 99.9) and percent negative agreement (specificity) 99.6% (95% CI: 98.0 -99.9). Concordance was high with a Gwet's Ac1 of 0.992. No significant differences were observed between the alpha and original variants.

CONCLUSIONS

The Chorus SARS-CoV-2 "Neutralizing" Ab test was highly sensitive and specific, and varies from most other currently available tests since it analyzes only antibodies with viral-neutralizing capacity.

Large scale production and characterization of SARS-CoV-2 whole antigen for serological test development

BACKGROUND

The rapid spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has generated a pandemic with alarming rates of fatality worldwide. This situation has had a major impact on clinical laboratories that have attempted to answer the urgent need for diagnostic tools, since the identification of coronavirus disease 2019 (COVID-19). Development of a reliable serological diagnostic immunoassay, with high levels of sensitivity and specificity to detect SARS-CoV-2 antibodies with improved differential diagnosis from other circulating viruses, is mandatory.

METHODS

An enzyme-linked immunosorbent assay (ELISA) using whole inactivated virus cultured in vitro, was developed to detect viral antigens. WB and ELISA investigations were carried out with sera of convalescent patients and negative sera samples. Both analyses were concurrently performed with recombinant MABs to verify the findings.

RESULTS

Preliminary data from 10 sera (5 patients with COVID-19, and 5 healthy controls) using this immunoassay are very promising, successfully identifying all of the confirmed SARS-CoV-2-positive individuals.

CONCLUSION

This ELISA appears to be a specific and reliable method for detecting COVID-19 antibodies (IgG, IgM, and IgA), and a useful tool for identifying individuals which have developed immunity to the virus.

Risk factors for distant metastases from carcinoma of the parotid gland

BACKGROUND

Distant metastases (DM) have become an increasingly common cause of death in cancer patients because of the increasing therapeutic control of locoregional disease. However, little data exist regarding the role of clinical factors in predicting the likelihood of DM in patients with carcinoma of the parotid gland.

METHODS

To analyze the incidence of DM and the factors involved in developing DM, the authors retrospectively studied clinical and survival data from 124 consecutive patients with parotid gland carcinoma who were surgically treated at the Institute of Otolaryngology of the University of Florence.

RESULTS

DM occurred in 33 of 124 patients (26.6%). Patients with high grade carcinoma had a higher occurrence of DM than those with low grade disease (30.6% vs. 17.9%; P = 0.033). The presence or absence of tumor positive cervical lymph nodes in dissection specimens significantly influenced the occurrence of DM (68.2% vs. 23.7%) (P = 0.007), as well as the number of histologically positive cervical lymph nodes (P = 0.014). Clinical signs of local tumor extension, particularly facial nerve impairment, were found to be associated with a higher rate of DM (P = 0.008). Moreover, tumor size (P = 0.0216) and clinical stage (P = 0.010) were prognostically significant in predicting the incidence of DM. Interestingly, locoregional tumor failure (P = 0.096) did not affect the risk of DM. Multivariate Cox proportional hazards analysis showed that clinical stage and facial nerve infiltration were the most important factors in predicting the risk of DMs (P = 0.010; hazard ratio [HR]: 3.75; 95% confidence interval [CI]: 1.14-13.05 and P = 0.041; HR: 2.75; 95% CI: 1.04-7.30, respectively).

CONCLUSIONS

Tumor stage and local aggressiveness were found to be the major prognostic factors in predicting the risk of distant failure in patients with carcinoma of the parotid gland.

Mt. Cimone Observatory: baseline station for the measurement of gaseous substances and radioactive tracers in the atmosphere

An extensive research program to record atmospheric physicochemical parameters and to track climatological trends was established at a remote Alpine station at Mt. Cimone Observatory in Italy. The main features of the study are outlined briefly and the results thus far collected, including surface ozone, carbon dioxide, stratospheric NO2 and O3, and airborne radioactivity are provided.

Value of combined assessment of physical health and functional status in community-dwelling aged: a prospective study in Florence, Italy

A survey of the health and social conditions of a representative sample of 967 persons aged 60 years and older from the city of Florence, Italy, was undertaken in 1980. In 1987, a follow-up survey of this cohort was performed. There were 391 documented deaths, 408 survivors, and 168 individuals who could not be located. Functional ability at baseline was assessed using a World Health Organization 14-item scale. Indicators of physical health status included chronic disease status, number of drugs, physician visits, and days of hospitalization. After adjustment for age and sex, both functional ability and indicators of physical health status were found to be independent, statistically significant predictors of mortality. The results of this study further support the view that biomedical and functional assessment are both necessary for a comprehensive evaluation of the older population.

[Our experience with antibiotic therapy in children hospitalized between 1979 and 1981]

The use of antibiotics in the Children Hospital of Florence has been studied considering the whole hospital for 1979 and only one department for 1980-81. 7832 clinical records of children admitted to the Hospital have been analyzed in order to get more informations about the quality of antibiotic treatment and to understand the causes of use and misuse of this kind of drugs in pediatric practice.

Amino acid composition of the diet in a region of Southern Tunisia

As part of a study of the effects of lysine supplementation of wheat products in Southern Tunisia one qualitative and four quantitative surveys of food consumption were carried out. The average diet provided 7.1 MJ (1,670 kcal), 42 g of protein and 1,280 mg of lysine per person per day. The overall dietary protein thus supplied only 31 mg of lysine/g of protein, or about 56% of the level recommended by the FAO/WHO Expert Committee on Protein Requirements. Addition of lysine to all wheat products to a final effective concentration of 0.2% would raise the dietary lysine level to 45 mg/g protein, or 82% of the FAO/WHO recommended level, at which time threonine would become limiting. Irrespective of whether the FAO/WHO pattern of 1973, breast milk, cow's milk, whole egg or a modification of the FAO pattern of 1957 was used to assess the quality of the protein in the diet, lysine was the first, and threonine the second limiting amino acid (except in comparison with breast milk, which showed tryptophan as the second limiting amino acid). In no case did there appear to be any problem with the sulfur-containing amino acids.

Nutritional correlates of child development in southern Tunisia. IV. The relation of deciduous dental eruption to somatic development

Deciduous dental eruption in a group of 658 children below 3 years of age in Southern Tunisia was found to be correlated with the general somatic development. On the other hand, this association was less close than that among the different components of somatic growth, suggesting that dental eruption is less affected by the factors which delay somatic growth in that area. Attempts were made to obtain methods of estimating the ages of children using the number of erupted deciduous teeth, both by means of regression equations and by a table of the median age of children with different numbers of pairs of teeth. In both cases the estimates obtainable are not accurate enough to do more than divide the children into coarse age groups. It is concluded that in anthropometric work there is no substitute for accurately known chronological ages.

Pentafluorophenyl-Metal Chemistry I

Pentafluorphenyl-zinn-Verbindungen können aus Organo-zinn-halogeniden, R4-nSnXn, und der Pentafluorphenyl - Grignard- Verbindung gewonnen werden. Bei der Verwendung eines hochsiedenden Lösungsmittels werden gute Ausbeuten erzielt, dennoch ist es zweckmäßig, Pentafluorphenyl-magnesiumbromid zunächst in Äthyl-äther darzustellen.

Die Zinn-Verbindungen sind an der Luft beständig und werden durch Wasser oder Äthanol nicht hydrolysiert. Starke Lewis - Säuren bewirken Spaltung: Bei der Einwirkung von Bortribromid auf Bis- (pentafluorphenyl) -di-n-butyl-zinn wurden Pentafluorphenyl-bordibromid und n-Butyl-bordibromid isoliert. Im Gegensatz dazu bleibt Tetrakis- (pentafluorphenyl) -zinn unter vergleichbaren Bedingungen unverändert.

Die Eigenschaften der beschriebenen Pentafluorphenyl-zinn-Verbindungen zeigen keine wesentlichen Abweichungen von denen der entsprechenden Phenyl-zinn-Verbindungen. Charakteristische Daten, einschließlich einiger Infrarot-Frequenzen, sind in einer Tabelle zusammengefaßt.