Molecular Epidemiology of Adenoviral Keratoconjunctivitis in Korea
2022; 42(6): 683-687
Ann Lab Med 2018; 38(1): 32-38
Published online January 28, 2018 https://doi.org/10.3343/alm.2018.38.1.32
Copyright © Korean Society for Laboratory Medicine.
Banseok Kim, M.D.1, Seung-Tae Lee, M.D.2, Sinyoung Kim, M.D.2*, Jong Rak Choi, M.D.2, and Hyun Ok Kim, M.D.2
1Department of Laboratory Medicine, National Health Insurance Service Ilsan Hospital, Goyang, Korea.
2Department of Laboratory Medicine, Yonsei University College of Medicine, Seoul, Korea.
Correspondence to: Corresponding author: Sinyoung Kim. Department of Laboratory Medicine, Yonsei University College of Medicine, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Korea. Tel: +82-2-2228-2452, Fax: +82-2-313-0956, sykim@yuhs.ac
This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
The DEL blood type, a very weak D variant, is a major concern in the field of transfusion medicine because of its potential to cause anti-D alloimmunization. We investigated the molecular basis of serologically D-negative phenotypes, including the DEL type, and the distribution of other blood group systems in the Korean population using the recently developed multiplex ligation-dependent probe amplification (MLPA) assay.
Blood group genotyping using the MLPA assay and RhCE phenotyping were performed on randomly selected 95 D-negative red blood cell products. The MLPA results were verified by multiplex PCR for the
Out of 95 cases, total deletion of the
MLPA assay correctly determined
Keywords: Rh-Hr blood-group system, Genotype, Multiplex ligation-dependent probe amplification
The Rh blood group D antigen is highly immunogenic in the human blood group system, and anti-D alloimmunization can cause severe hemolytic transfusion reactions and hemolytic disease in the fetus and newborn [1]. DEL type is a very weak D variant that cannot be detected by routine serological tests and presents as a D-negative phenotype unless adsorption and elution studies are performed [2,3]. In addition, DEL type can cause anti-D alloimmunization despite small amounts of D antigen on red blood cell (RBC) surfaces. Several cases of anti-D alloimmunization resulting from RBC transfusion of DEL type have been reported [4,5,6,7]. Currently, about 30
Owing to the very low frequency of the D-negative phenotype (0.15%) in Korea, ‘RhD-Negative Blood Club’ was organized to assist the supply of D-negative blood products since 1973 [8,12]. However, Seo et al [12] reported that 20 individuals with DEL type (n=16, 14.5%), weak D (n=2, 1.8%), and partial D (n=2, 1.8%) were classified as D-negative among 110 RhD-Negative Blood Club members. Therefore, the accurate determination of D variant (including DEL type) is important to protect D-negative individuals from inadvertent alloimmunization to the D antigen. Several
Recently, a multiple ligation-dependent probe amplification (MLPA) assay has been developed to detect
The performance of the MLPA assay has not been validated in the East Asian population with serologically D-negative phenotype. In this study, we investigated the molecular basis of the D-negative phenotype, including the DEL type, and determined the distribution and prevalence of other blood group genotypes in the Korean population.
We investigated 95 randomly selected samples of D-negative RBC products that were supplied by the Korea Red Cross Blood Service and the Hanmaum Blood Center in Korea between August 2015 and October 2015. The D antigen status of the RBC products was confirmed by D typing using two different anti-D reagents [Bioclone (Ortho-Clinical Diagnostics, Raritan, NJ, USA) and Anti-D (RH1) IGM1 (Diagast, Loos, France) in the Korean Red Cross Blood Service; Bioclone and Bioscot (Millipore, Livingstone, UK) in the Hanmaum Blood Center], and the indirect antiglobulin technique (IAT) in each Blood Center. An adsorption-elution test was not performed routinely by blood centers.
All blood samples were serotyped for C/c and E/e antigens using monoclonal anti-C, -c, -E, and -e reagents (Ortho-Clinical Diagnostics) with the standard tube method according to the manufacturer's recommendations. This study was approved by the Institutional Review Board of Severance Hospital, Yonsei University Health System (4-2015-0882).
Genomic DNA was isolated using the QIAamp DSP DNA Blood Mini kit (Qiagen, Hilden, Germany) according to the manufacturer's protocol, and genomic DNA concentration and purity were assessed using a spectrophotometer (NanoDrop 2000, Thermo Fischer Scientific, Waltham, MA, USA).
We used commercial SALSA MLPA Probemixes P401-A1, P402-A1, and P403-A1 Blood Group Genotyping kits (MRC-Holland, Amsterdam, the Netherlands) for the MLPA assay. The three probe mixes contained a total of 129 probes, which included 104 wild type and/or mutation probes to determine the presence, absence, and copy number of the major blood group alleles and variant alleles. The other 25 reference probes included were selected from chromosomal regions supposed to be chromosomally stable in diseases. All procedures were carried out according the manufacturer's protocol. In brief, ligation was performed using 100 ng of genomic DNA in the following steps: denaturation at 98℃ for 5 minutes, hybridization with each SALSA Probemix at 60℃ for 16 hours, ligation reaction by Ligase-65 (MRC-Holland) at 54℃ for 15 minutes, and ligase inactivation by incubation at 98℃ for 5 minutes. Finally, multiplex PCR was performed using fluorescence-labeled universal primers, dNTPs, PCR buffer, and polymerase for 35 cycles (95℃ for 30 seconds, 60℃ for 30 seconds, 72℃ for 1 minute) using a C1000 thermal Cycler (BioRad, Cressier, Switzerland). The fragments were analyzed using an ABI 3130 Genetic Analyzer (Applied Biosystems, Foster, CA, USA) and GeneMarker 2.2 software (SoftGenetics, State College, PA, USA). Zygosity was determined as the signal ratio between tested samples and control samples.
Multiplex PCR was performed to confirm the
Direct sequencing of the
Three
Among the 95 total cases,
The prevalence of the other 16 blood group genotypes and expected phenotypes in the 95 RhD-negative donors are described in Table 3. For the MNS blood group, the numbers of cases with
The frequency of the D-negative phenotype varies from 0.5% in East Asians to 3-7% in Africans and 12-18% in Caucasians [20,21]. In Caucasians, the most common cause of the D-negative phenotype is a homozygous total deletion of the
In Koreans, about 75% of D-negative individuals have a total deletion of the
The DEL type is phenotypically determined by the absence of agglutination in the indirect antiglobulin test and a positive result in the adsorption/elution technique [3,22]. As the sensitivity of the indirect antiglobulin test may vary across laboratories and false-positive results in adsorption/elution technique may also occur, it is difficult to accurately define the borderline between the DEL type and a true D-negative phenotype [2]. This leads to the necessity of
DEL type arises from several molecular mechanisms, including splice site mutations, missense mutations, frame shift mutations,
Previous reports showed that the DEL type is highly associated with the RhC+ phenotype (Cc or CC) [2,12,19,28,29,30]. Among 126 DEL cases in Taiwan, Wang et al [28] reported that 107 (84.9%) cases were Cc and 19 (15.1%) cases were CC. Srijinda et al [29] also reported that 42 (84.0%) cases were Cc and eight (16.0%) cases were CC among 50 DEL cases in Thailand. This association between DEL type and RhC phenotype might be explained by the suppressive effect of C, where D antigen density is suppressed by the C antigen [19]. Recently published reports showed a similar distribution pattern in Korea, and the cc phenotype was exclusively found in D-negative individuals with total
Since numerous blood group antigens can be accurately determined by a single test, several comprehensive blood group genotyping platforms have been developed and are currently used in diverse situations [31]. The most important clinical utility of this test is to identify donors lacking high-prevalence antigens or multiple common antigens like those for rare donor programs. The frequency of the D-negative phenotype is 0.15% in Koreans, about 1/100th of the frequency in the Caucasian population [8]. Considering that the DEL type is relatively common in D-negative Koreans, the true D-negative individuals fall into the rare blood donor category. Comprehensive blood group genotyping methods could be valuable tools for accurately determining the
In this study, we further evaluated the performance of an MLPA assay in 17 blood group systems other than the
In conclusion, the MLPA assay correctly determined
No potential conflicts of interest relevant to this article were reported.
This study was supported by a faculty research grant of Yonsei University College of Medicine for 2011 (6-2011-0089).
Primers used for multiplex PCR and sequencing
Method | Genomic target | Nucleotide sequence | Product size (bp) | References |
---|---|---|---|---|
Multiplex PCR (set A) | F: CCACATGAACATGATGCACA | 127 | [18] | |
R: CAAACTGGGTATCGTTGCTG | ||||
F: TAAGCAAAAGCATCCAA | 186 | [6] | ||
R: ATGGTGAGATTCTCCT | ||||
Multiplex PCR (set B) | F: GTTGTAACCGAGTGCTGGGGATTC | 123 | [19] | |
R: TGCCGGCTCCGACGGTATC | ||||
F: TCCACTTTCCACCTCCCTGC | 256 | [19] | ||
R: GCAGCCAACTTCCCCTGTG | ||||
Multiplex PCR (internal control) | F: TGCCTTCCCAACCATTCCCTTA | 434 | [13] | |
R: CCACTCACGGATTTCTGTTGTGTTTC | ||||
Sequencing | F: AGATACTGTCGTTTTGACACACAAT | 463 | In this study | |
R: GCTGAGGACTGCAGATAGGG |
RhCE phenotype and
Type of | RhCE phenotype | No. (%) of samples | Subtotal (%) | |
---|---|---|---|---|
Total deletion | ce | 60 (63.2) | 74 (77.9) | |
cEe | 9 (9.5) | |||
Cce | 5 (5.3) | |||
Cce | 4 (4.2) | 4 (4.2) | ||
Cce | 14 (14.7) | 17 (17.9) | ||
CcEe | 3 (3.2) | |||
Total | 95 (100) |
Genotype frequency of RBC antigens in the 95 RhD-negative samples
Blood group system | Expected phenotypes | Genotype | Genotype frequency (%), n=95 |
---|---|---|---|
002 MNS | M+N−S+s− | 0 (0) | |
M+N−S+s+ | 7 (7.4) | ||
M+N−S−s+ | 21 (22.1) | ||
M+N+S+s− | 0 (0) | ||
M+N+S+s+ | 6 (6.3) | ||
M+N+S−s+ | 37 (38.9) | ||
M−N+S+s− | 0 (0) | ||
M−N+S+s+ | 0 (0) | ||
M−N+S−s+ | 24 (25.3) | ||
005 Lutheran | Lu(a+b−) | 0 (0) | |
Lu(a+b+) | 0 (0) | ||
Lu(a−b+) | 95 (100) | ||
006 Kell | K+k− | 0 (0) | |
K+k+ | 0 (0) | ||
K−k+ | 95 (100) | ||
Kp(a+b−) | 0 (0) | ||
Kp(a+b+) | 0 (0) | ||
Kp(a−b+) | 95 (100) | ||
Js(a+b−) | 0 (0) | ||
Js(a+b+) | 0 (0) | ||
Js(a−b+) | 95 (100) | ||
008 Duffy | Fy(a+b−) | 80 (84.2) | |
Fy(a+b+) | 13 (13.7) | ||
Fy(a−b+) | 2 (2.1) | ||
009 Kidd | Jk(a+b−) | 25 (26.3) | |
Jk(a+b+) | 48 (50.5) | ||
Jk(a−b+) | 22 (23.2) | ||
010 Diego | Di(a+b−) | 0 (0) | |
Di(a+b+) | 12 (12.6) | ||
Di(a−b+) | 83 (87.4) | ||
Wr(a+b−) | 0 (0) | ||
Wr(a+b+) | 0 (0) | ||
Wr(a−b+) | 95 (100) | ||
011 Yt | Yt(a+b−) | 95 (100) | |
Yt(a+b+) | 0 (0) | ||
Yt(a−b+) | 0 (0) | ||
013 Scianna | Sc:1,−2 | 95 (100) | |
Sc:1,2 | 0 (0) | ||
Sc:−1,2 | 0 (0) | ||
014 Dombrock | Do(a+b−) | 4 (4.2) | |
Do(a+b+) | 15 (15.8) | ||
Do(a−b+) | 78 (82.1) | ||
Jo(a−) | 0 (0) | ||
Gy(a−) | 0 (0) | ||
Hy(−) | 0 (0) | ||
015 Colton | Co(a+b−) | 95 (100) | |
Co(a+b+) | 0 (0) | ||
Co(a−b+) | 0 (0) | ||
016 LW | Lw(a+b−) | 95 (100) | |
Lw(a+b+) | 0 (0) | ||
Lw(a−b+) | 0 (0) | ||
020 Gerbich | Ge:2,3,4 | 95 (100) | |
Ge:−2,3,4 | 0 (0) | ||
Ge:−2,−3,4 | 0 (0) | ||
021 Cromer | Cr(a+) | 95 (100) | |
Cr(a−) | 0 (0) | ||
022 Knops | Kn(a+b−) | 95 (100) | |
Kn(a+b+) | 0 (0) | ||
Kn(a−b+) | 0 (0) | ||
023 Indian | In(a+b−) | 0 (0) | |
In(a+b+) | 0 (0) | ||
In(a−b+) | 95 (100) | ||
024 Ok | Ok(a+) | 95 (100) | |
Ok(a−) | 0 (0) |