Impaired Seroconversion After Severe Acute Respiratory Syndrome Coronavirus 2 mRNA Vaccine in Patients With Thymic Epithelial Tumors

Case report: Potential role of immunotherapy in thymic malignancies: a unique case of a durable and complete response upon an immune checkpoint inhibitor

Thymic epithelial tumors are rare malignancies with an incidence of 1.7 cases per million people per year. They pose significant management challenges due to their association with autoimmune disorders. In this case report, we present the 21-year history of a patient diagnosed with advanced B2/B3 thymoma and Good's syndrome. The patient achieved a complete and durable response after receiving only two cycles of the immune checkpoint inhibitor Nivolumab. However, this positive outcome was accompanied by the development of severe immune-related myocarditis complicated by reactivation of cytomegalovirus. Moreover, the patient developed a highly uncommon subdiaphragmatic pararectal dissemination of the thymic tumor, which is a condition rarely described in the literature. Despite the success in achieving complete and durable response with immune checkpoint inhibitors, the emergence of immune-related adverse events highlights the potential challenges associated with these treatments, emphasizing the need for careful monitoring and a comprehensive understanding of the intricate interplay between cancer, immune system dysregulations and immunotherapy.

COVID-19 in patients with thymic epithelial tumors with or without Good's syndrome: a single-center retrospective study

INTRODUCTION

Thymic epithelial tumors (TETs) are rare neoplasms often associated with immune-related disorders. Patients with Good's syndrome (GS), an adult-acquired TET-related immunodeficiency, are at a high risk of mortality due to infectious diseases. This study aims to examine COVID-19 occurrence and severity in TET patients, with or without GS.

METHODS

Clinical records of TET patients referred to the Regional Coordinating Center for Rare Tumors of Campania Region were retrospectively collected. During the observation period, elapsing from March 2020 to April 2023, the following data were collected: occurrence of SARS-CoV-2 infection; COVID-19 severity, according to the National Institute of Health (NIH) illness categories; COVID-19 treatment. COVID-19 occurrence and severity were assessed in the overall population and correlated with the presence of GS and/or other immune-related dysregulations.

RESULTS

Overall, 47 TET patients were included in the study; 27 of these (57.4%) had GS. All participants had received a full cycle of mRNA vaccine for SARS-CoV2., Thirty-one patients (66.0%) experienced COVID-19, of whom 18 (58.0%) had previously received a diagnosis of GS. No significant association of GS and/or other immune-related dysregulations with SARS-CoV-2 infection occurrence was detected (Fisher's exact test p = 1 and p = 0.3587, respectively). Among patients with GS, 8 (45.0%) reported a COVID-19 severity score of ≥ 3; whereas, only 1 of the 13 patients without GS (7.7%) had a severity score of ≥ 3. The correlation between presence of GS and COVID-19 severity (score 1 or 2 vs. ≥ 3) was statistically significant (p = 0.0448). No statistically significant association between COVID-19 severity and other immune-related syndromes were found (p = 1). Of note, all the hospitalized patients for NIH 4 and 5 COVID-19 had GS.

CONCLUSIONS

Our data suggest that TET patients, especially those with GS, require a careful multidisciplinary monitoring for SARS-CoV-2 infection, in order to establish tailored treatments and prophylactic protocols.

Serum biomarkers of inflammation and vascular damage upon SARS-Cov-2 mRNA vaccine in patients with thymic epithelial tumors

OBJECTIVES

Thymic epithelial tumors (TET) patients are at high risk of autoimmune and hypoimmune complications. Limited evidence is available on the potential risk of immune-related and inflammatory reactions induced by SARS-Cov-2 vaccine in this patient population.

METHODS

In order to identify subjects at higher risk for vaccine complications, we prospectively evaluated a panel of serum biomarkers related to inflammation (TNF-α, IL-1β, -6, -10, -12, and -17A, IFN-α, β and γ, MPO, MMP-9), and vascular damage (E- and P-selectin, VEGF-A, P-ANCA and MCP-1) in 44 TET patients and in 30 healthy controls along the whole SARS-Cov-2 vaccine cycle.

RESULTS

About 50 % of subjects (either TET and controls) showed an increase of serum biochemical markers of inflammation and endothelial damage with a large heterogeneity of values. Such increase appeared early, after the first dose in control subjects and later, after the second dose in TET patients (in which we observed mainly an increase of inflammatory biomarkers). The values normalized after about 3 months and did not increase after the third, booster dose. No autoimmune or vascular complications were observed in the study subjects and no difference was observed in terms of vaccine response among subjects showing serum biomarkers increase and those who experienced no changes.

CONCLUSIONS

Our data highlight the relevance of Sars-Cov-2 vaccine in TET patients, as it resulted safe and prevented severe COVID-19. However, further studies are awaited to explore the mechanisms and the potential consequences of the observed increase of serum inflammatory and vascular damage biomarkers.

Immunocytometric analysis of patients with thymic epithelial tumors revealed that COVID-19 vaccine booster strongly enhanced the immune response

Background

Thymic epithelial tumors (TETs) are rare malignancies with heterogeneous clinical manifestations. The high frequency of autoimmune paraneoplastic disorders observed in such patients requires caution when using COVID-19 vaccines. Furthermore, TETs are often associated with severe immunodeficiency, making it difficult to predict vaccine immunization. Therefore, we aimed to evaluate immune response to COVID-19 vaccine in patients with TETs.

Methods

We conducted a prospective study enrolling patients who underwent the SARS-Cov-2 mRNA full vaccine cycle (two doses plus a booster after 6 months of BNT162b2). All patients were enrolled before receiving 1st vaccine dose and were followed over the vaccination cycle for up to 6 months after the booster dose to i) assess humoral and cellular responses, ii) define biomarkers predictive of effective immunization, and iii) evaluate the safety of the vaccine.

Results

At the end of the full vaccine cycle, 27 (61.4%) patients developed humoral and 38 (86.4%) cellular responses (IFN γ release by stimulated cells) and showed an increase in activated TH1 and TH17 cells, particularly significant after the booster dose. The number of B and T lymphocytes at baseline was predictive of humoral and cellular responses, respectively. Patients with no evidence of tumor lesions had a higher probability of achieving a humoral response than those with evidence of the disease. Furthermore, the percentage of patients with immune-related disorders (75%), particularly Good's syndrome (47.7%) and myasthenia gravis (29.5%), did not change over the entire vaccine cycle. Overall, 19 of the 44 enrolled patients (43.2%) had COVID-19 during the observation period; none required hospitalization or oxygen support, and no fatalities were observed.

Conclusion

SARS-Cov-2 mRNA vaccine determines the immune responses in patients with TET, particularly after the booster dose, and in patients with no evidence of tumor lesions. Preliminary analysis of B and T lymphocytes may help identify patients who have a lower probability of achieving effective humoral and cellular responses and thus may need passive immunization. The vaccine prevented severe COVID-19 infection and is safe.