Immunoglobin G/total antibody testing for SARS-CoV-2: A prospective cohort study of ambulatory patients and health care workers in two Belgian oncology units comparing three commercial tests

Abstract

Background Coronavirus disease (COVID-19) is interfering heavily with the screening, diagnosis and treatment of cancer patients. Better knowledge of the seroprevalence and immune response after Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection in this population is important to manage them safely during the pandemic. Methods 922 cancer patients, 100 non-cancer patients and 94 healthcare workers (HCW) attending the Multidisciplinary Oncology Unit of Antwerp University Hospital from 24 th of March 2020 till 31 st of May 2020, and in the Oncology Unit of AZ Maria Middelares Hospital Gent from 13 th of April 2020 till 31 st of May 2020 participated. The Alinity® (A; Abbott) and Liaison® (D; Diasorin) commercially available assays were used to measure SARS-CoV-2 IgG, while total SARS-CoV-2 Ig was measured by Elecsys® (R; Roche) Results In the overall study population IgG/total SARS-CoV-2 antibodies were found in respectively 32/998 (3.2%), 68/1020(6.7%), 37/1010 (3.7%) and of individuals using the A, D or R test. Forty six out of 618 (7.4%) persons had a positive SARS-CoV-2 polymerase chain reaction (RT-PCR) test. Seroprevalence in cancer patients (A:2.2%, D:6.2%, R:3.0%), did not significantly differ from that in non-cancer patients (A:1.1%, D:5.6%, R:0.0%), but was lower than the HCW (A:13%, D:12%, R:12%; respectively Fisher’s exact test p=0.00001, p=0.046, p=0.0004). A positive SARS-CoV-2 RT-PCR was found in 6.8% of the cancer patients, 2.3% of the non-cancer patients and 28.1% of the HCW (Fisher’s exact test p=0.0004). Correlation between absolute value of the different Ig tests was poor in the cancer population. Dichotomizing a positive versus negative test result, the A and R test correlated well (kappa 0.82 p McNemar test=0.344), while A and D, and R and D did not (respectively kappa 0.49 and 0.57; result significantly different p McNemar test=<0.0001 for both). The rate of seroconversion (>75%) and median absolute antibody levels (A: 7.0 vs 4.7; D 74.0 vs 26.6, R: 16.34 vs 7.32; all > P Mann Whitney test=0.28) in cancer patients and HCW with a positive RT-PCR at least 7 days earlier did not show any differences. However, none (N=0/4) of the patients with hematological tumors had seroconversion and absolute antibody levels remained much lower compared to patients with solid tumors (R: 0.1 vs 37.6, p 0.003; D 4.1 vs 158, p 0.008) or HCW (all p<0.0001). Conclusion HCW were at high risk to be infected by SARS-CoV-2 during the first wave of the pandemic. Seroprevalence in cancer patients was low in the study period. Although Ig immune response in cancer patients with solid tumors does not differ from healthy volunteers, patients with hematological tumors have a very poor humoral immune response. This has to be taken into account in future vaccination programs in this population. SARS-C...

Reduced humoral immune response after BNT162b2 coronavirus disease 2019 messenger RNA vaccination in cancer patients under antineoplastic treatment

“… 10 , 11 , 12 , 13 In addition, low or even absent antibody response after SARS-CoV-2 infection has been reported, particularly in patients with advanced cancer and B-cell hematological malignancies. 7 , 8 Emerging evidence shows that SARS-CoV-2 vaccination efficacy might be lower in elderly and immunocompromised. 22 , 23 Our prospective interventional trial demonstrated an acceptable safety profile of the BNT162b2 mRNA COVID-19 vaccine with a reduced and delayed antibody response in both solid and hematological cancer patients receiving anti-neoplastic treatment.…”

“…Recently, it was shown that SARS-CoV-2 exposed patients with hematological malignancies display heterogeneous humoral immune response, an exhausted T-cell phenotype and a high prevalence of prolonged viral shedding. 5 , 6 , 7 , 8 Although patients with solid tumors often develop immune response signatures similar to those of non-cancer patients 9 , they remain at increased risk of severe COVID-19. 10 , 11 , 12 , 13 Hence, according to various oncological associations, high priority for vaccination should be given to these patients, regardless of age.…”

COVID-19 in immunocompromised populations: implications for prognosis and repurposing of immunotherapies

“…Vaccination is encouraged in these immunosuppressed patient groups, although it is possible that the immune responses will be less robust, as has been seen in response to natural infection. 152 153 Indeed, early studies are showing comparable safety, but reduced immunogenicity has been observed for these populations, including patients with HM, 154–156 SOTRs, 157 and those with rheumatological diseases. 158 159 To achieve comparable vaccine efficacy, further strategies employing altered vaccine schedules, doses, or adjustment to immunosuppression during vaccination might be needed, and should be accomplished only in the context of a clinical trial.…”

COVID‐19 elicits an impaired antibody response against SARS‐CoV‐2 in patients with haematological malignancies

“…Sensitivity and specificity of these tests was at least 98% in a head-to-head comparison study, 12 with some divergent results in seroprevalence studies on cancer patients. 13 Continuous variables are expressed as median, minimum, and maximum values. Categorical variables are presented as frequencies and percentages.…”