Absolute Lymphocyte Count After COVID-19 Vaccination Is Associated with Vaccine-Induced Hypermetabolic Lymph Nodes on ¹⁸F-FDG PET/CT: A Focus in Breast Cancer Care

Abstract

Rationale: We aimed to predict the presence of vaccine-induced hypermetabolic lymph nodes (v-HLN) on 18 F-FDG PET/CT after Coronavirus disease 2019 (COVID-19) vaccination and determine their association with lymphocyte counts. Methods: In this retrospective single-center study, we included consecutive patients who underwent 18 F-FDG PET/CT imaging after mRNA-or viral vector-based COVID-19 vaccination between early March and late April 2021. Demographic, clinical parameters and absolute lymphocyte count (ALC) were collected and their association with the presence of v-HLN in the draining territory was studied by logistic regression.Results: Two hundred and sixty patients were eligible, including 209 (80%) women and 145 (56%) with breast cancer. The median age was 50 years (range, 23-96). Two hundred thirty-three patients (90%) received the mRNA vaccine. Ninety (35%) patients had v-HLN with a median SUVmax of 3.7 [range, 2.0-26.3] and 74 (44%) displayed lymphopenia with a median ALC of 1.4 G/L [range, 0.3-18.3]. Age ≤ 50 years (odds ratio [OR] 2.2, 95%CI 1.0-4.5), the absence of lymphopenia (OR 2.2, 95%CI 1.1-4.3) and the delay from the last vaccine injection to the date of 18 F-FDG PET/CT, if < 30 days (OR 2.6, 95%CI 1.3-5.6), were independent factors for v-HLN in multivariate analysis. In breast cancer patients, the absence of lymphopenia was the only independent factor significantly associated with v-HLN (OR 2.9, 95%CI 1.2-7.4).Conclusions: Patients with normal values of ALC after COVID-19 vaccine were more likely to have v-HLN on 18 F-FDG PET/CT, which might both be associated to a stronger immune response to vaccination. KEYWORDS 18 F-FDG PET/CT; COVID-19 vaccination; absolute lymphocyte count; hypermetabolic lymph nodes; immune response. KEY-POINTSQUESTION: Could we use lymphocyte count lymphocyte for predicting the presence of vaccineinduced hypermetabolic lymph node(s) in the drainage territory on 18 F-FDG PET/CT following COVID-19 vaccination?PERTINENT FINDINGS: This retrospective and monocentric study included 260 vaccinated patients who underwent 18 F-FDG PET/CT following mRNA based-or viral vector based-COVID-19 vaccination. Patients' absolute lymphocyte count (>lower limit of normal), along with patients' age (≤ 50 years) and the timing of last injection dose (< 30 days), significantly correlated with vaccine-induced hypermetabolic lymph node(s).IMPLICATIONS FOR PATIENT CARE: Patients displaying normal count of lymphocytes after COVID-19 vaccination are more likely to present vaccine-induced hypermetabolic lymph node(s) on 18 F-FDG PET/CT and could subsequently have higher seropositivity likelihood and antibody titers.

Ipsilateral Malignant Axillary Lymphadenopathy and Contralateral Reactive Lymph Nodes in a COVID-19 Vaccine Recipient With Breast Cancer

“…Moderna vaccines have shown to have slightly higher likelihood of nodal reactivity compared to Pfizer vaccine [ 1 ]. A recent retrospective study suggested that lymphopenia maybe associated with lower incidence of nodal reactivity, further supporting the link between nodal reactivity and vaccine immunogenicity [ 11 ].…”

Improved Survival and Quality of Life Through an Integrative, Multidisciplinary Oncological Approach: Pathophysiological Analysis of Four Clinical Cancer Cases and Review of the Literature

“…The most widely used vaccines were based on messenger ribonucleic acid (mRNA) molecules, which stimulate host cells to synthesize the Spike surface protein of Coronavirus. A large body of data has demonstrated the safety of such vaccines ( Faermann et al, 2021 ; Seban et al, 2021 ). Our patient received the two doses of Pfizer-BioNTech (COMIRNATY) BNT162b2 mRNA between March and April 2021, at the correct 3-weeks interval.…”

“…In this case, AC combined with the mRNA Covid-19 vaccine induced a prolonged phase of neutropenia that was probably due to the immune reaction to lymphocyte populations concentrating at peripheral drainage sites. This phenomenon may reflect the relative reduction in peripheral blood and the atypical figures found especially in BC patients following Covid-19 vaccination ( Faermann et al, 2021 ; Seban et al, 2021 ).…”

Misdiagnosis of Reactive Lymphadenopathy Remotely After COVID-19 Vaccination: A Case Report and Literature Review

“…In this case, accompanying manifestations interfered with the diagnosis, including transient fever, decreased white cell and lymphocyte counts, increased inflammatory markers (ESR, PCT, and SF), and abnormal coagulation function. A previous study reported a decrease in lymphocytes after COVID-19 vaccination (26), and elevated PCT and CRP were independent risk factors for death in patients with COVID-19 (47). As all tests for specific infections were negative, and the patient fully recovered without medical intervention, we retrospectively supposed that these manifestations were also vaccine reactions.…”

“…Concerning imaging-detected reactive lymphadenopathy after COVID-19 vaccination, the majority of cases were identified on PET scans, mainly during cancer surveillance. This condition normally involved transient 18-fluorinefluorodeoxyglucose ( 18 F-FDG) uptake in ipsilateral lymph nodes, ranging from intense to gradually regressed after administration (13,19,22,(24)(25)(26). However, the maximal standardized uptake value (SUVmax) should not be solely used to differentiate between benign and malignant lymph nodes (14).…”