Single-Nucleotide Polymorphism in Genes Encoding G Protein Subunits GNB3 and GNAQ Increase the Risk of Cardiovascular Morbidity among Patients Undergoing Renal Replacement Therapy.

Single-nucleotide polymorphisms in G protein subunits are linked to an increased risk of cardiovascular events among the general population. We assessed the effects of GNB3 c.825C > T, GNAQ -695/-694GC > TT, and GNAS c.393C > T polymorphisms on the risk of cardiovascular events among 454 patients undergoing renal replacement therapy. The patients were followed up for a median of 4.5 years after the initiation of dialysis. Carriers of the TT/TT genotype of GNAQ required stenting because of coronary artery stenosis (p = 0.0009) and developed cardiovascular events involving more than one organ system (p = 0.03) significantly earlier and more frequently than did the GC/TT or GC/GC genotypes. Multivariate analysis found that the TT/TT genotype of GNAQ was an independent risk factor for coronary artery stenosis requiring stent (hazard ratio, 4.5; p = 0.001), cardiovascular events (hazard ratio, 1.93; p = 0.04) and cardiovascular events affecting multiple organs (hazard ratio, 4.9; p = 0.03). In the subgroup of male patients left ventricular dilatation with abnormally increased LVEDD values occurred significantly more frequently in TT genotypes of GNB3 than in CT/CC genotypes (p = 0.007). Our findings suggest that male dialysis patients carrying the TT genotype of GNB3 are at higher risk of left ventricular dilatation and that dialysis patients carrying the TT/TT genotype of GNAQ are prone to coronary artery stenosis and severe cardiovascular events.

GNB3 c.825C>T (rs5443) Polymorphism and Risk of Acute Cardiovascular Events after Renal Allograft Transplant

The c.825C>T single-nucleotide polymorphism (rs5443) of the guanine nucleotide-binding protein subunit ß3 (GNB3) results in increased intracellular signal transduction via G-proteins. The present study investigated the effect of the GNB3 c.825C>T polymorphism on cardiovascular events among renal allograft recipients posttransplant. Our retrospective study involved 436 renal allograft recipients who were followed up for up to 8 years after transplant. The GNB3 c.825C>T polymorphism was detected with restriction fragment length polymorphism (RFLP) polymerase chain reaction (PCR). The GNB3 TT genotype was detected in 43 (10%) of 436 recipients. Death due to an acute cardiovascular event occurred more frequently among recipients with the TT genotype (4 [9%]) than among those with the CC/CT genotypes (7 [2%]; p = 0.003). The rates of myocardial infarction (MI)−free survival (p = 0.003) and acute peripheral artery occlusive disease (PAOD)−free survival (p = 0.004) were significantly lower among T-homozygous patients. A multivariate analysis showed that homozygous GNB3 c.825C>T polymorphism exerted only a mild effect for the occurrence of myocardial infarction (relative risk, 2.2; p = 0.065) or acute PAOD (relative risk, 2.4; p = 0.05) after renal transplant. Our results suggest that the homozygous GNB3 T allele exerts noticeable effects on the risk of MI and acute PAOD only in the presence of additional nonheritable risk factors.

NAT2 polymorphisms as a cause of metamizole-induced agranulocytosis.

Metamizole is a widely prescribed NSAID with excellent analgesic and antipyretic properties. Although very effective, it is banned in some countries because of the risk for severe agranulocytosis. We here describe three patients with metamizole-associated agranulocytosis. Patient #1 suffered from agranulocytosis and tonsillitis followed by severe sepsis by Streptococcus pneumoniae and Epstein-Barr virus reactivation. Her dizygotic twin sister (patient #2) also suffered from agranulocytosis after a surgical intervention. Patient #3 initially had a tonsillitis and also developed neutropenia after metamizole intake. For all patients, pharmacogenetic diagnostic for the genes CYP2C9, CYP2C19 and NAT2, which are involved in metamizole metabolism and degradation of toxic metabolites, was initiated. Pharmacogenetic analysis revealed NAT2 slow acetylator phenotype in all three patients. Additionally, patient #2 is an intermediate metabolizer for CYP2C19 and patient #3 is a poor metabolizer for CYP2C9. Impairment of these enzymes causes a reduced degradation of toxic metabolites, for example, 4-methylaminoantipyrine (4-MAA) or 4-aminoantipyrine. The metabolite 4-MAA can complex with hemin, which is an early breakdown product during hemolysis. Hemolysis is often observed during invasive infections or after surgical procedures. It is known that the 4-MAA/hemin complex can induce cytotoxicity in the bone marrow and interrupt granulocyte maturation. In conclusion, metamizole-induced agranulocytosis most likely was a consequence of the underlying genetical predisposition, that is, polymorphisms in the genes NAT2, CYP2C9 and CYP2C19. Hemolysis may have increased the toxicity of metamizole metabolites.

ACE2 polymorphism and susceptibility for SARS-CoV-2 infection and severity of COVID-19.

OBJECTIVES: The RNA virus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for coronavirus disease 2019 (COVID-19). Cell entry is mediated by the human angiotensin-converting enzyme II (ACE2). ACE2 and its close homolog angiotensin-converting enzyme I (ACE) are currently discussed candidate genes, in which single-nucleotide polymorphisms (SNPs) could alter binding or entry of SARS-CoV-2 and enhance tissue damage in the lung or other organs. This could increase the susceptibility for SARS-CoV-2 infection and the severity of COVID-19. PATIENTS AND METHODS: We performed genotyping of SNPs in the genes ACE2 and ACE in 297 SARS-CoV-2-positive and 253 SARS-CoV-2-negative tested patients. We analyzed the association of the SNPs with susceptibility for SARS-CoV-2 infection and the severity of COVID-19. RESULTS: SARS-CoV-2-positive and SARS-CoV-2-negative patients did not differ regarding demographics and clinical characteristics. For ACE2 rs2285666, the GG genotype or G-allele was significantly associated with an almost two-fold increased SARS-CoV-2 infection risk and a three-fold increased risk to develop serious disease or COVID-19 fatality. In contrast, the ACE polymorphism was not related to infection risk or severity of disease. In a multivariable analysis, the ACE2 rs2285666 G-allele remained as an independent risk factor for serious disease besides the known risk factors male gender and cardiovascular disease. CONCLUSIONS: In summary, our report appears to be the first showing that a common ACE2 polymorphism impacts the risk for SARS-CoV-2 infection and the course of COVID-19 independently from previously described risk factors.

The influence of IFITM3 polymorphisms on susceptibility to SARS-CoV-2 infection and severity of COVID-19.

BACKGROUND AND AIMS: The interferon-induced transmembrane protein 3 (IFITM3) plays an important role in the adaptive and innate immune response by inhibiting viral membrane hemifusion between the host and viral cell cytoplasm. Single nucleotide polymorphisms (SNPs) in the gene IFITM3 have been associated with susceptibility and severity of influenza or other viral infections. We aimed to analyze the role of SNPs in the gene IFITM3 in SARS-CoV-2 infection. METHODS: We performed genotyping of the SNPs rs12252 and rs34481144 in the gene IFITM3 in 239 SARS-CoV-2-positive and 253 SARS-CoV-2-negative patients. We analyzed the association of the SNPs with susceptibility to SARS-CoV-2 infection and severity of COVID-19. RESULTS: SARS-CoV-2-positive and SARS-CoV-2-negative patients did not differ regarding demographics. Neither IFITM3 rs12252 nor rs34481144 polymorphisms were related to SARS-CoV-2 infection risk or severity of COVID-19. Interestingly, we observed the putative deleterious rs12252 CC genotype only in SARS-CoV-2-positive patients (N = 2). Also, we found a non-significant higher frequency of rs34481144 A-allele carriers in the patients with 'serious' COVID-19. CONCLUSIONS: In summary, we could not confirm the recently reported influence of polymorphisms in the gene IFITM3 on SARS-CoV-2 infection risk or severity of COVID-19 in a German cohort. Additional studies are needed to clarify the influence of the rs12252 CC genotype on SARS-CoV-2 infection risk and the rs34481144 A-allele on course of COVID-19.

BRAFV600E mutation: A promising target in colorectal neuroendocrine carcinoma.

To determine the role of BRAFV600E mutation and MAPK signaling as well as the effects of BRAF and MEK directed therapy in gastroenteropancreatic neuroendocrine neoplasia (GEP-NEN), with a focus on highly aggressive gastroenteropancreatic neuroendocrine carcinoma (GEP-NEC). Using Sanger sequencing of BRAF exon 15 we determined the frequency of BRAFV600E mutations in 71 primary GEP-NENs. MEK phosphorylation was examined by immunohistochemistry in corresponding tissue samples. To evaluate the biological relevance of BRAFV600E mutation and MAPK signaling in GEP-NECs, effects of a pharmacological BRAF and MEK inhibition were analyzed in NEC cell lines both in vitro and in vivo. BRAFV600E mutation was detected in 9.9% of all GEP-NENs. Interestingly, only NECs of the colon harbored BRAFV600E mutations, leading to a mutation frequency of 46.7% in this subgroup of patients. In addition, a BRAFV600E mutation was significantly associated with high levels of MEK phosphorylation (pMEK) and advanced tumor stages. Pharmacological inhibition of BRAF and MEK abrogated NEC cell growth, inducing G1 cell cycle arrest and apoptosis only in BRAFV600E mutated cells. BRAF inhibitor dabrafenib and MEK inhibitor trametinib prevented growth of BRAFV600E positive NEC xenografts. High frequencies of BRAFV600E mutation and elevated expression levels of pMEK were detected in biologically aggressive and highly proliferative colorectal NECs. We provide evidence that targeting BRAF oncogene may represent a therapeutic strategy for patients with BRAF mutant colorectal NECs.

Diagnostic pathology of early systemic cancer: ERBB2 gene amplification in single disseminated cancer cells determines patient survival in operable esophageal cancer.

Early metastatic dissemination and evolution of disseminated cancer cells (DCCs) outside the primary tumor is one reason for the failure of adjuvant therapies because it generates molecular genotypes and phenotypes different from primary tumors, which still underlie therapy decisions. Since ERBB2 amplification in esophageal DCCs but not in primary tumor cells predict outcome, we aimed to establish an assay with diagnostic reliability for single DCCs or circulating tumor cells. For this, we evaluated copy number alterations of more than 600 single DCCs from multiple cancer types to define reference regions suitable for quantification of target regions, such as ERBB2. We then compared ERBB2 quantitative PCR (qPCR) measurements with fluorescent in situ hybridization (FISH) data of various breast cancer cell lines and identified the aberration-calling threshold. The method was applied to two independent cohorts of esophageal cancer patients from Hamburg (n = 59) and Düsseldorf (n = 53). We found a high correlation between the single cell qPCR assay and the standard FISH assay (R = 0.98) and significant associations between amplification and survival for both patient cohorts (Hamburg (HH), p = 0.033; Düsseldorf (D), p = 0.052; pooled HH + D, p = 0.002) when applied to DCCs of esophageal cancer patients. Detection of a single ERBB2-amplified DCC was the most important risk factor for death from esophageal cancer (relative risk = 4.22; 95% CI = 1.91-9.32; p < 0.001). In our study, we detected ERBB2-amplified cells in 7% of patients. These patients could benefit from anti-ERBB2 targeting therapies.

Establishment and Characterization of a Novel Cell Line Derived from a Small Cell Neuroendocrine Carcinoma of the Anal Canal.

BACKGROUND: Gastroenteropancreatic neuroendocrine carcinomas (GEP-NECs) are biologically aggressive tumors, associated with a very poor survival. Due to their rarity, our knowledge on GEP-NEC biology is very limited. The aim of this study was to establish a GEP-NEC cell line model that might contribute to a better understanding of this rare malignant disease to further develop novel therapeutic approaches in preclinical studies. METHODS: Small cell neuroendocrine cancer cell line NEC-DUE3 was derived from a lymph node metastasis of a neuroendocrine carcinoma (NEC) located at the anal canal. Morphological characteristics and the expression of neuroendocrine markers were comprehensively investigated. For genetic profiling, NEC-DUE3 cells were analyzed by DNA fingerprinting. Chromosomal aberrations were mapped by array comparative genomic hybridization. NEC-DUE3 cell tumorigenicity was evaluated in vivo and the sensitivity to chemotherapeutic agents was assessed in vitro. RESULTS: NEC-DUE3 cells were characterized by the expression of molecular markers that are commonly observed in GEP-NECs, were sensitive to treatment with cisplatin, and able to form tumors in immunodeficient mice. CONCLUSION: We established and characterized the first small cell GEP-NEC cell line that may serve as a valuable tool to create a better understanding of the biology of these rare tumors and to develop novel treatment strategies.

Disseminated tumour cells with highly aberrant genomes are linked to poor prognosis in operable oesophageal adenocarcinoma.

BACKGROUND: Chromosomal instability (CIN) has repeatedly been identified as a prognostic marker. Here we evaluated the percentage of aberrant genome per cell (PAG) as a measure of CIN in single disseminated tumour cells (DTC) isolated from patients with operable oesophageal adenocarcinoma (EAC), to assess the impact of CINhigh DTCs on prognosis. METHODS: We isolated CK18positive DTCs from bone marrow (BM) or lymph node (LN) preparations of operable EAC patients. After whole-genome amplification, single DTCs were analysed for chromosomal gains and losses using metaphase-based comparative genomic hybridisation (mCGH). We calculated the PAG for each DTC and determined the critical threshold value that identifies high-risk patients by STEPP (Subpopulation Treatment Effect Pattern Plot) analysis in two independent EAC patient cohorts (cohort #1, n=44; cohort #2; n=29). RESULTS: The most common chromosomal alterations observed among the DTCs were typical for EAC, but the DTCs showed a varying PAG between individual patients. Generally, LNDTCs displayed a significantly higher PAG than BMDTCs. STEPP analysis revealed an increasing PAG of DTCs to be correlated with an increased risk for short survival in two independent EAC cohorts as well as in the corresponding pooled analysis. In all three data sets (cohort #1, cohort #2 and pooled cohort), PAGhigh DTCs conferred an independent risk for a significantly decreased survival. CONCLUSIONS: The analysis of PAG/CIN in solitary marker-positive DTCs identifies operable EAC patients with poor prognosis, indicating a more aggressive minimal residual disease.

Peritoneal sarcomatosis: site of origin for the establishment of an in vitro and in vivo cell line model to study therapeutic resistance in dedifferentiated liposarcoma.

Approximately 50-70 % of patients with retroperitoneal or intraabdominal sarcoma develop a relapse after surgical therapy, including peritoneal sarcomatosis, an extremely rare site of metastatic disease which is associated with an extremely poor prognosis. Accordingly, the establishment of a permanent cell line derived from peritoneal sarcomatosis might provide a helpful tool to understand the biological behavior and to develop new therapeutic strategies. Thus, we established and characterized a liposarcoma cell line (Lipo-DUE1) from a peritoneal sarcomatosis that was permanently cultured without showing any morphological changes. Lipo-DUE1 cells exhibited a spindle-shaped morphology and positive staining for S100. Tumorigenicity was demonstrated in vitro by invasion and migration assays and in vivo by using a subcutaneous xenograft mouse model. In addition, aCGH analysis revealed concordant copy number variations on chromosome 12q in the primary tumor, peritoneal sarcomatosis, and Lipo-DUE1 cells that are commonly observed in liposarcoma. Chemotherapeutic sensitivity assays revealed a pronounced drug-resistant phenotype of Lipo-DUE1 cells to conventionally used chemotherapeutic agents. In conclusion, we describe for the first time the establishment and characterization of a liposarcoma cell line derived from a peritoneal sarcomatosis. Hence, in the future, the newly established cell line Lipo-DUE1 might serve as a useful in vitro and in vivo model to investigate the biological behavior of liposarcoma and to assess novel targeted therapies.

Serum microRNA profiles as prognostic/predictive markers in the multimodality therapy of locally advanced adenocarcinomas of the gastroesophageal junction.

Neoadjuvant multimodality treatment is frequently applied to improve the poor prognosis of locally advanced adenocarcinomas of the gastroesophageal junction. This study aimed to asses if serum microRNA profiles are useable as response indicators in this therapeutic setting. Fifty patients with locally advanced adenocarcinomas of the gastroesophageal junction were included in the study. All patients received neoadjuvant therapy and subsequently underwent surgical resection. Histomorphologic regression was defined as major histopathological response when resected specimens contained less than 10% vital residual tumor cells. Circulating RNA was isolated from pretherapeutic/post-neoadjuvant blood serum samples. RNA from nine patients was applied to PCR microarray analyses Based on these findings possible predictive miRNA markers were validated by quantitative RT-PCR analyses. Depending on the histomorphologic regression, a differential serum microRNA profile was identified by microarray analyses. Based on the divergent miRNA pattern, miR-21, miR-192, miR-222, miR-302c, miR-381 and miR-549 were selected for further validation. During neoadjuvant therapy, there was a significant increase of miR 222 and miR-549. Although on an expanded patient cohort, the six microRNAs could not be validated as markers for therapy response, there was a significant correlation between a high miR-192 and miR-222 expression with a high T-category as well as miR-302c and miR-222 expression significantly correlated with overall survival. Comprehensive miRNA profiling showed a differential microRNA expression pattern depending on the histomorphologic regression in the multimodality therapy of locally advanced adenocarcinomas of the gastroesophageal junction. Moreover, using single RT-PCR analyses a prognostic impact of miR-222 and miR-302c was detected.

Genomic high-resolution profiling of single CKpos/CD45neg flow-sorting purified circulating tumor cells from patients with metastatic breast cancer.

BACKGROUND: Circulating tumor cells (CTCs) are promising surrogate markers for systemic disease, and their molecular characterization might be relevant to guide more individualized cancer therapies. To enable fast and efficient purification of individual CTCs, we developed a work flow from CellSearch(TM) cartridges enabling high-resolution genomic profiling on the single-cell level. METHODS: Single CTCs were sorted from 40 CellSearch samples from patients with metastatic breast cancer using a MoFlo XDP cell sorter. Genomes of sorted single cells were amplified using an adapter-linker PCR. Amplification products were analyzed by array-based comparative genomic hybridization, a gene-specific quantitative PCR (qPCR) assay for cyclin D1 (CCND1) locus amplification, and genomic sequencing to screen for mutations in exons 1, 9, and 20 of the phosphatidylinositol-4,5-bisphosphate 3-kinase, catalytic subunit alpha (PIK3CA) gene and exons 5, 7, and 8 of the tumor protein p53 (TP53) gene. RESULTS: One common flow-sorting protocol was appropriate for 90% of the analyzed CellSearch cartridges, and the detected CTC numbers correlated positively with those originally detected with the CellSearch system (R(2) = 0.9257). Whole genome amplification was successful in 72.9% of the sorted single CTCs. Over 95% of the cells displayed chromosomal aberrations typical for metastatic breast cancers, and amplifications at the CCND1 locus were validated by qPCR. Aberrant CTCs from 2 patients harbored mutations in exon 20 of the PIK3CA gene. CONCLUSIONS: This work flow enabled effective CTC isolation and provided insights into genomic alterations of CTCs in metastatic breast cancer. This approach might facilitate further molecular characterization of rare CTCs to increase understanding of their biology and as a basis for their molecular screening in the clinical setting.

The single nucleotide polymorphism rs4986790 (c.896A>G) in the gene TLR4 as a protective factor in corona virus disease 2019 (COVID-19).

Background and aims: Several factors, such as hypertension and diabetes mellitus, are known to influence the course of coronavirus disease 2019 (COVID-19). However, there is currently little information on genetic markers that influence the severity of COVID-19. In this study, we specifically investigated the single nucleotide polymorphism (SNP) rs4986790 in the TLR4 gene to identify a universal marker for preclinical prediction of COVID-19 disease progression. Methods: We analyzed the influence of demographics, pre-existing conditions, inflammatory parameters at the time of hospitalization, and TLR4 rs4986790 genotype on the outcome of COVID-19 in a comprehensive cohort (N = 1570). We performed multivariable analysis to investigate the impact of each factor. Results: We confirmed that younger patient age and absence of pre-existing conditions were protective factors against disease progression. Furthermore, when comparing patients with mild SARS-CoV-2 infection with patients who required hospitalization or intensive care or even died due to COVID-19, the AG/GG genotype of TLR4 rs4986790 was found to be a protective factor against COVID-19 disease progression (OR: 0.51, 95% CI: 0.34 - 0.77, p = 0.001). In addition, we demonstrated that low levels of interleukin-6 (IL-6) and procalcitonin (PCT) had a favorable effect on COVID-19 disease severity. In the subsequent multivariable analysis, we confirmed the absence of cardiovascular disease, low levels of IL-6 and PCT, and TLR4 rs4986790 AG/GG genotypes as independent predictors of potential hospitalization and reduction of severe or fatal disease course. Conclusion: In this study, we identified an additional genetic factor that may serve as an invariant predictor of COVID-19 outcome. The TLR4 rs4986790 AG/GG genotype reduced by half the risk of COVID-19 patients requiring hospitalization, intensive care or to have a fatal outcome. In addition, we were able to confirm the influence of previously known factors such as pre-existing conditions and inflammatory markers upon the onset of disease on the course of COVID-19. Based on these observations, we hereby provide another prognostic biomarker that could be used in routine diagnostics as a predictive factor for the severity of COVID-19 prior to SARS-CoV-2 infection.

Early CYP3A5 Genotype-Based Adjustment of Tacrolimus Dosage Reduces Risk of De Novo Donor-Specific HLA Antibodies and Rejection among CYP3A5-Expressing Renal Transplant Patients.

BACKGROUND/OBJECTIVES: Our previous retrospective single-center cohort study found, at 3-year follow-up, a trend toward low tacrolimus trough levels and an increased risk of de novo donor-specific anti-HLA antibodies (DSAs) and of antibody-mediated rejection (ABMR) in CYP3A5-expressing patients. Determining CYP3A5-expression status immediately after renal transplant would allow early genotype-based dosage adjustment of tacrolimus and might prevent the occurrence of de novo DSAs and ABMR, improving transplant outcome. METHODS: 160 renal allograft recipients who underwent renal transplant at the University Hospital Essen between May 2019 and May 2022 were genotyped for the CYP3A5 rs776746 polymorphism within the first two weeks after transplant, and genotype-based dose adjustment of tacrolimus was performed for the follow-up of 2 years. RESULTS: CYP3A5 expression was detected in 33 (21%) of the 160 patients. Tacrolimus trough levels were similar in CYP3A5 expressers and nonexpressers over the entire 2-year follow-up period. However, we observed a trend toward slightly higher tacrolimus trough levels in CYP3A5 expressers, who, as expected, required tacrolimus dosages twice as high as did nonexpressers during follow-up. Calcineurin inhibitor (CNI) nephrotoxicity-free survival rates were comparable between CYP3A5 expressers and nonexpressers (p = 0.49). Rejection-free survival rates (p = 0.89), de novo anti-HLA antibody-free survival rates (p = 0.57) and de novo DSA-free survival rates (p = 0.61) did not differ between the two groups. CONCLUSIONS: Early detection of CYP3A5-expression status and resultant genotype-based adjustment of tacrolimus dosage after renal transplant protected patients from transplant rejection and de novo DSA formation and was not associated with increased incidence of CNI toxicity among CYP3A5 expressers.

Characteristics and Long-Term Outcome of 535 Patients with Autoimmune Hepatitis-The 20-Year Experience of a High-Volume Tertiary Center.

Background and aims: Autoimmune hepatitis (AIH) is a complex and progressive inflammatory liver disease characterized by immune-mediated destruction of the liver parenchyma, hypergammaglobulinemia, the presence of circulating autoantibodies, and good response to immunosuppressive therapy. Since the prevalence of AIH is relatively rare, data on the clinical course and the long-term outcome are scarce. Patients and methods: We retrospectively analyzed the data of 535 well-documented AIH patients treated at the University Hospital Essen between 2000 and 2020. Results: The majority of patients were middle-aged females (75% women, mean age 45 years) with AIH type 1 (97%). Approximately 32% of patients were diagnosed with cirrhosis due to AIH, 29% had concomitant autoimmune (predominantly autoimmune thyroiditis), and 10% had psychiatric diseases, respectively. Skin tumors were the most common malignant diseases (47% of all tumors), while hepatocellular carcinoma rarely occurred (only six cases). Overall long-term mortality and liver-associated mortality were 9.16% and 4.67%, respectively. However, long-term survival was strongly associated with disease remission. Conclusions: Although AIH is a silent disease and cirrhosis is present in many cases, a favorable long-term prognosis can be achieved by consequent immunosuppressive therapy. The incidence of (liver-associated) complications seems to be lower in comparison to other etiologies, such as viral hepatitis or NASH, and mainly depends on the long-term side effects of immunosuppressive therapy.

Durability of Immune Response after Application of a Third Dose of SARS-CoV-2 Vaccination in Liver Transplant Recipients.

Immunogenicity after SARS-CoV-2 vaccination is known to be impaired in liver transplant (LT) recipients, but the results after the application of a third dose show significant improvement in seroconversion rates. In the general population, the antibody response wanes over the course of time after two doses of the vaccination, but seems to be more robust after the application of three doses. Still, the durability of the antibody response in LT recipients who receive a third dose of SARS-CoV-2 vaccination has not been analyzed yet. We therefore assessed antibody responses in a total of 300 LT recipients and observed antibody titers for six months each after patients had received the second and the third doses of the vaccination, explicitly excluding all patients who had suffered from SARS-CoV-2 infection. The initial antibody response was compared to a control group of 122 healthcare workers. After the application of two doses of the vaccination, 74% of LT recipients (158 out of 213) developed antibodies against SARS-CoV-2; this result depended significantly on whether the patients were taking the medication mycophenolate mofetil, and on the age of the patients. Antibody titers declined significantly within six months from 407 BAU/mL (IQR: 0-1865) to 105 BAU/mL (IQR: 0-145) (p ≤ 0.001), but increased after the application of the third vaccine dose in 92% of patients (105 out of 114), showing an antibody response (p ≤ 0.001). After a further six-month period, despite showing a decline from 2055 BAU/mL (IQR: 500 to >2080) to 1805 BAU/mL (IQR: 517 to >2080), the waning of antibody titers was not significant (p = 0.706), and antibody durability appeared to be more robust than that after the second dose. In conclusion, our study confirms the high efficacy of the application of a third dose of SARS-CoV-2 vaccination in LT recipients, and a reasonably sustained humoral response with superior durability in comparison to antibody kinetics after the application of the second dose of the vaccination.

Influence of the Single Nucleotide Polymorphisms rs12252 and rs34481144 in IFITM3 on the Antibody Response after Vaccination against COVID-19.

The COVID-19 mRNA vaccine is the first mRNA vaccine approved for human administration by both the U.S. Food and Drug Administration and the European Medicines Agency. Studies have shown that the immune response and the decay of immunity after vaccination with the COVID-19 vaccines are variable within a population. Host genetic factors probably contribute to this variability. In this study, we investigated the effect of the single-nucleotide polymorphisms rs12252 and rs34481144 in the interferon-induced transmembrane protein (IFITM) 3 gene on the humoral immune response after vaccination against COVID-19 with mRNA vaccines. Blood samples were collected from 1893 healthcare workers and medical students at multiple time points post-vaccination and antibody titers against the SARS-CoV-2 S1 protein receptor binding domain were determined at all time points. All participants were genotyped for the rs34481144 and rs12252 polymorphisms in the IFITM3 gene. After the second and third vaccinations, antibody titer levels increased at one month and decreased at six months (p < 0.0001) and were higher after the booster vaccination than after the basic immunization (p < 0.0001). Participants vaccinated with mRNA-1273 had a higher humoral immune response than participants vaccinated with BNT162b2. rs12252 had no effect on the antibody response. In contrast, carriers of the GG genotype in rs34481144 vaccinated with BNT162b2 had a lower humoral immune response compared to A allele carriers, which reached statistical significance on the day of the second vaccination (p = 0.03) and one month after the second vaccination (p = 0.04). Further studies on the influence of rs12252 and rs34481144 on the humoral immune response after vaccination against COVID-19 are needed.

Antibody responses elicited by mRNA vaccination in firefighters persist six months and correlate inversely with age and directly with BMI.

Knowledge regarding the sustainability of immune responses after COVID-19 vaccination is important, e.g., to decide whom and when to booster. Thus, we analyzed antibody titers in firefighters six months after vaccination with the mRNA-based vaccine Comirnaty. SARS-CoV-2 spike-binding antibodies (bAb) were quantified and compared to peak responses determined in healthcare workers (HCW). For the firefighters, neutralizing antibodies (nAb) were also analyzed. Six months after the second vaccine dose, all analyzed firefighters had detectable bAb, and 91% exhibited nAb titers above 1:16. However, actual titers six months after vaccination were over 12-fold lower than in the HCW control group four weeks after vaccination. bAb and nAb responses showed a significant correlation, and age correlated inversely with antibody responses. Unexpectedly, participants with a body mass index over 25 had higher neutralization titers after six months. All participants with very low neutralization titers were offered booster vaccination. The booster vaccination improved the extent and sustainability of antibody responses.

GNB3 c.825c>T polymorphism influences T-cell but not antibody response following vaccination with the mRNA-1273 vaccine.

Background: Immune responses following vaccination against COVID-19 with different vaccines and the waning of immunity vary within the population. Genetic host factors are likely to contribute to this variability. However, to the best of our knowledge, no study on G protein polymorphisms and vaccination responses against COVID-19 has been published so far. Methods: Antibodies against the SARS-CoV-2 spike protein and T-cell responses against a peptide pool of SARS-CoV-2 S1 proteins were measured 1 and 6 months after the second vaccination with mRNA-1273 in the main study group of 204 participants. Additionally, antibodies against the SARS-CoV-2 spike protein were measured in a group of 597 participants 1 month after the second vaccination with mRNA-1273. Genotypes of GNB3 c.825C>T were determined in all participants. Results: The median antibody titer against the SARS-CoV-2 spike protein and median values of spots increment in the SARS-CoV-2 IFN-γ ELISpot assay against the S1-peptide pool were significantly decreased from months 1 to 6 (p < 0.0001). Genotypes of GNB3 c.825C>T had no influence on the humoral immune response. At month 1, CC genotype carriers had significantly increased T-cell responses compared to CT (p = 0.005) or TT (p = 0.02) genotypes. CC genotype carriers had an almost 6-fold increased probability compared to TT genotype carriers and an almost 3-fold increased probability compared to T-allele carriers to mount a SARS-CoV-2-specific T-cell response above the median value. Conclusion: CC genotype carriers of the GNB3 c.825C>T polymorphism have an increased T-cell immune response to SARS-CoV-2, which may indicate better T-cell-mediated protection against COVID-19 after vaccination with mRNA-1273.

CC Genotype of GNAS c.393C>T (rs7121) Polymorphism Has a Protective Effect against Development of BK Viremia and BKV-Associated Nephropathy after Renal Transplant

The GNAS gene encodes the alpha-subunit of the stimulatory G-protein (Gαs) in humans and mice. The single-nucleotide polymorphism of GNAS, c.393C>T, is associated with an elevated production of Gαs and an increased formation of cyclic adenosine monophosphate (cAMP). In the present study, we analyzed the effect of this GNAS polymorphism on a renal allograft outcome. We screened a cohort of 436 renal allograft recipients, who were retrospectively followed up for up to 5 years after transplant. GNAS genotypes were determined with polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assays. The 393T allele was detected in 319 (73%) recipients (113 recipients with TT and 206 with CT genotype) and the CC genotype in 117 (27%). The CC genotype was associated with a significantly lower frequency of BK viremia (CC, 17 recipients (15%); T 84 (26%)); p = 0.01; TT, 27 vs. CC, 17, p = 0.07; TT, 27 vs. CT, 57, p = 0. 46; CT, 57 vs. CC, 17, p = 0.01) and BKV-associated nephropathy (CC, 3 recipients (3%); T, 27 (8%); p = 0.03; TT,10 vs. CC, 3, p = 0.04; TT, 10 vs. CT,17, p = 0.85; CT, 17 vs. CC,3, p = 0.04) after transplant. BKV-associated nephropathy-free survival was significantly better among CC genotype carriers than among T allele carriers (p = 0.043; TT vs. CC, p = 0.03; CT vs. CC, p = 0.04; TT vs. CT, p = 0.83). Multivariate analysis indicated an independent protective effect of the CC genotype against the development of both BK viremia (relative risk. 0.54; p = 0.04) and BKV-associated nephropathy after renal transplant (relative risk. 0.27; p = 0.036). The GNAS 393 CC genotype seems to protect renal allograft recipients against the development of BK viremia and BKV-associated nephropathy.