The relationship between Lewis/Secretor genotypes and serum carbohydrate antigen 19-9 levels in a Korean population

A hepatic sparganosis misdiagnosed as intrahepatic mass-forming cholangiocarcinoma: a case report and literature review

Hepatic sparganosis (HS) is extremely rare and has not been previously reported in Eastern China. We report the diagnosis and treatment of a patient with HS from Xuzhou City, Jiangsu Province, China. The patient was admitted due to an acute biliary tract infection, and the symptoms improved after treatment at the Gastroenterology Department. During an ultrasound examination on admission, an abnormal echo was incidentally discovered at the junction of the left and right lobes of the liver. Thereafter, upper abdominal computed tomography (CT) and magnetic resonance imaging (MRI) non-contrast and contrast-enhanced examinations, and serum tumor biomarker examination were completed. After a multidisciplinary treatment (MDT) discussion at the Department of Hepatobiliary Surgery, the patient was diagnosed with intrahepatic mass-type cholangiocarcinoma (IMCC) and surgery was recommended. The patient underwent surgical treatment, and postoperative pathology revealed HS. No signs of intrahepatic recurrence were observed during the 1-year follow-up period.

Relationship Between Rotavirus P[6] Infection in Korean Neonates and Histo-Blood Group Antigen: a Single-Center Study

Background

Rotaviruses are a major cause of pediatric gastroenteritis. The rotavirus P[6] genotype is the most prevalent genotype isolated from Korean neonates but has rarely been reported in other countries. Histo-blood group antigen (HBGA) is known to play an important role in rotavirus infection. We investigated the relationship between rotavirus genotype and HBGA-Lewis blood type in Korean children and explored the reasons for the predominance of rotavirus P[6] strain in Korean neonates.

Methods

Blood and stool samples were collected from 16 rotavirus-infected patients. Rotavirus G (VP7) and P (VP4) genotyping was performed using reverse transcription-PCR and sequencing. Lewis antigen phenotypes (Le^a/Le^b) were tested, and HBGA-Lewis genotype was determined by sequencing the secretor (FUT2) and Lewis (FUT3) genes. Deduced amino acid sequences and three-dimensional structures of the VP8* portion of the rotavirus VP4 protein were analyzed.

Results

All P[6] rotaviruses were isolated from neonates under one month of age, who were negative or weakly positive for the Le^b antigen. However, 10 of the 11 non-P[6] rotaviruses were isolated from older children who were Le^b antigen-positive. The VP8* amino acid sequences differed among P[6], P[4], and P[8] genotypes. Korean P[6] strains showed a unique VP8* sequence with amino acid substitutions, including Y169 > L169, which differed from the sequences of P[6] strains from other countries.

Conclusions

The predominance of the rotavirus P[6] genotype in Korean neonates may be related to the interaction between HBGA-Lewis antigen and the VP8* portion of the VP4 protein, and this information will be helpful in future neonatal vaccine development.

Neutrophil-to-lymphocyte ratio and carbohydrate antigen 19-9 as prognostic markers for advanced pancreatic cancer patients receiving first-line chemotherapy

BACKGROUND

A decline in serum carbohydrate antigen 19-9 (CA19-9) levels during systemic chemotherapy is considered as a prognostic marker for patients with advanced pancreatic cancer. Neutrophil-to-lymphocyte ratio (NLR) has been extensively studied as a simple and useful indicator of prognosis in various cancers including pancreatic cancer.

AIM

To assess the prognostic significance of NLR and CA19-9 in patients with advanced pancreatic adenocarcinoma received first-line chemotherapy according to CA19-9 positivity.

METHODS

We retrospectively analyzed patients diagnosed with advanced pancreatic cancer who received first-line chemotherapy between January 2010 and July 2017 at the Catholic University of Seoul St. Mary’s Hospital. Patients were divided according to CA19-9 positivity (CA19-9-positive vs -negative groups) and pre-and post-treatment NLR levels. To determine cut-off value of NLR and CA19-9 reduction, time-dependent receiver operating characteristic curve was applied. We evaluated overall survival (OS) and progression-free survival (PFS) for each group using Kaplan-Meier method, and we performed multivariate analyses on the entire cohort.

RESULTS

We included 271 patients in this study. Cut-off value of NLR and CA19-9 reduction was determined as 2.62 and 18%. Multivariate analysis showed that post-treatment NLR < 2.62 and reduction of ≥ 18% of baseline CA19-9 were significantly associated with OS and PFS. Post-treatment NLR ≥ 2.62 showed hazard ratio (HR) of 2.47 [95% confidence interval (CI): 1.84-3.32, P < 0.001] and CA19-9 decline (≥ 18%) showed HR of 0.51 (95%CI: 0.39-0.67, P < 0.001) for OS. When CA19-9-positive patients were divided into groups according to CA19-9 response (responder vs non-responder) and post-treatment NLR (< 2.62 vs ≥ 2.62), CA19-9 responder and post-treatment NLR < 2.62 group showed better survival than CA19-9 non-responder and post-treatment NLR ≥ 2.62 group (OS 11.0 mo vs 3.9 mo, P < 0.001; PFS 6.3 mo vs 2.0 mo, P < 0.001). The combination of CA19-9 decline and post-treatment NLR showed a significant correlation with clinical response in CA 19-9 positive group. Within the CA19-9-negative group, the post-treatment NLR < 2.62 group showed better survival than the post-treatment NLR ≥ 2.62 group (OS 12.7 mo vs 7.7 mo, P < 0.001; PFS 6.7 mo vs 2.1 mo, P < 0.001), and post-treatment NLR showed correlation with clinical response.

CONCLUSION

In advanced pancreatic cancer patients positive for CA19-9 and treated with systemic chemotherapy, the combination of post-treatment NLR < 2.62 and 18% decline of CA19-9 at the first response evaluation is a good prognostic marker. Post-treatment NLR < 2.62 alone could be used as a prognostic marker and an adjunctive tool for response evaluation in CA19-9-negative patients.

Gene Variants That Affect Levels of Circulating Tumor Markers Increase Identification of Patients With Pancreatic Cancer

BACKGROUND & AIMS

Levels of carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and cancer antigen 125 (CA-125) in blood are used as markers to determine the response of patients with cancer to therapy, but are not used to identify patients with pancreatic cancer.

METHODS

We obtained blood samples from 504 patients undergoing pancreatic surveillance from 2002 through 2018 who did not develop pancreatic cancer and measured levels of the tumor markers CA19-9, CEA, CA-125, and thrombospondin-2. Single-nucleotide polymorphisms (SNPs) in FUT3, FUT2, ABO, and GAL3ST2 that have been associated with levels of tumor markers were used to establish SNP-defined ranges for each tumor marker. We also tested the association between additional SNPs (in FUT6, MUC16, B3GNT3, FAM3B, and THBS2) with levels of tumor markers. To calculate the diagnostic specificity of each SNP-defined range, we assigned the patients under surveillance into training and validation sets. After determining the SNP-defined ranges, we determined the sensitivity of SNP-adjusted tests for the tumor markers, measuring levels in blood samples from 245 patients who underwent resection for pancreatic ductal adenocarcinoma (PDAC) from 2010 through 2017.

RESULTS

A level of CA19-9 that identified patients with PDAC with 99% specificity had 52.7% sensitivity. When we set the cut-off levels of CA19-9 based on each SNP, the test for CA19-9 identified patients with PDAC with 60.8% sensitivity and 98.8% specificity. Among patients with FUT3 alleles that encode a functional protein, levels of CA19-9 greater than the SNP-determined cut-off values identified 66.4% of patients with PDAC, with 99.3% specificity. In the validation set, levels of CEA varied among patients with vs without SNP in FUT2, by blood group, and among smokers vs nonsmokers; levels of CA-125 varied among patients with vs without the SNP in GAL3ST2. The use of the SNPs to define the ranges of CEA and CA-125 did not significantly increase the diagnostic accuracy of the assays for these proteins. Combining data on levels of CA19-9 and CEA, CA19-9 and CA-125, or CA19-9 and thrombospondin-2 increased the sensitivity of detection of PDAC, but slightly reduced specificity.

CONCLUSIONS

Including information on SNPs associated with levels of CA19-9, CEA, and CA-125 can improve the diagnostic accuracy of assays for these tumor markers in the identification of patients with PDAC. Clinicaltrials.gov no: NCT02000089.

Systematic sequence analysis of the FUT3 gene identifies 11 novel alleles in the Sindhi and Punjabi populations from Pakistan

The FUT3 (Lewis) gene is responsible for the expression of Lewis fucosyltransferase, which is required for the synthesis of the structural determinants of both Lewis^a and Lewis^b specificity. These factors play an important role not only in clinical but also in medico-legal investigations. The gene sequence is highly polymorphic and ethnically specific. In the current study, we performed systematic sequence analysis of the coding region of FUT3 by DNA sequencing to investigate the genetic variations of FUT3 and the molecular basis of the Lewis phenotype in the Sindhi and Punjabi populations of Pakistan. Twenty-three point mutations were observed, including 7 unreported mutations, among which two missense mutations (490 G > A and 959 T > C) were predicted to be deleterious to enzyme activity by software assessment. In total, we observed 24 Lewis alleles, including 11 novel ones. However, all unreported missense mutations were present in Lewis-negative alleles confirmed previously. According to genotypic data, the Lewis-negative phenotypic frequencies were 11.5% and 22.93% in the Sindhi and Punjabi ethnic groups, respectively. Moreover, we found that le^202,314 and le^59,1067 were predominant among Lewis-negative alleles, while the frequency of le^59,1067 in the Punjabi population was significantly higher than that in the Sindhi population. In summary, our study revealed that there is a relatively high degree of sequence variation of the Lewis gene in Pakistani populations and provided the first genetic data on FUT3 in these two ethnic groups from Pakistan. The allele types and their frequencies showed that these ethnic groups exhibit more Caucasian components.

Distribution of Lewis and Secretor polymorphisms and corresponding CA19-9 antigen expression in a Chinese population

The Lewis (FUT3) and Secretor (FUT2) genes, corresponding to secretion of Lewis ABO (H) histo‐blood group antigen CA19‐9, are highly polymorphic with differences between populations. In this study, the FUT3 and FUT2 genes in 316 Chinese participants were sequenced to detect polymorphisms, and the associated CA19‐9 antigen secretion was also measured. In total, 14 genotypes of FUT3 and 10 genotypes of FUT2 were verified. Le/Le, Le/le^59,508 and Le/le⁵⁹ were the main genotypes of FUT3 with frequencies of 53.2%, 10.7% and 3.5%, respectively. Se/Se, Se/se³⁸⁵ and se³⁸⁵/se³⁸⁵ were the main genotypes of FUT2, with frequencies of 21.4%, 18.6% and 16.2%, respectively. The alleles le¹⁰⁶⁷ and le⁵⁰⁸ were found extensively in the Chinese population, and the frequency of allele se³⁸⁵ was shown to be higher than previously reported. Phenotype analysis revealed that 9.8% of individuals were the Lewis‐negative type and 22.5% were the secretor‐negative type. Combined phenotypes showed that 3.2% of participants were of ‘double‐negative’ phenotype (le, se) and 19.3% were of single dominant non‐secretor phenotype (Le, se). Serum Lewis antigen CA19‐9 levels were significantly different between subgroups and consistent with the defined phenotype. Our study revealed the unique distribution of Lewis and Secretor polymorphisms in a large Chinese population, and decoded the combined genotypes of the two CA19‐9‐related genes.

Investigation of unexpected serum CA19-9 elevation in Lewis-negative cancer patients

BACKGROUND

Cancer patients with a Lewis (a-b-) phenotype have no carbohydrate antigen 19-9 (CA19-9) in their serum. However, we found a small but distinct elevation in the serum CA19-9 level in three cancer patients with the Lewis-negative phenotype. Here, we investigated the reason of such phenomena.

METHODS

Six cancer patients with a Lewis-negative phenotype were selected by very low CA19-9 concentrations: three showed a small elevation (Group A) and the other three showed no elevation (Group B) in the serum CA19-9. We investigated the difference by analyzing the Lewis/Secretor genotypes.

RESULTS

All of the six patients with a Le (a-b-) phenotype were genuine Le-negative genotypes: four individuals were homozygous for le1 (le(59,508)), one patient was compound heterozygous for le1 (le(59,508)) and le2 (le(59,1067)) and one patient was compound heterozygous for le1 and le(202,314). As for the Secretor gene, the three patients in Group B were homozygous for Se2 (one patient) or compound heterozygous for Se2 and sej (two patients), while the patients in Group A were all homozygous for sej genotypes.

CONCLUSIONS

Even genuinely Le-negative patients, who genetically lack the Le enzyme and theoretically never produce CA19-9, occasionally show a slight increase in serum CA19-9 level when they are homozygous for Se-negative genotypes and suffer from advanced cancer with overproduction of glycans as precursors of CA19-9. Although such cases are not frequent, we should be acquainted with the correlation between serum CA19-9 values and genotypes of Lewis and Secretor genes.