Association between maternal coronavirus disease 2019 and transient tachypnea of the newborn: a single-center study.

BACKGROUND: Limited clinical reports have investigated the effects of maternal coronavirus disease 2019 (COVID-19) on fetuses and neonates. PURPOSE: This retrospective study aimed to assess the impact of maternal COVID-19 on neonates during the perinatal period, including neonatal clinical outcomes, versus the outcomes of neonates of mothers without COVID-19. METHODS: Neonates born to COVID-19-infected mothers at the National Health Insurance Service Ilsan Hospital between February 2021 and March 2022 were included. Those with gestational age (GA) ≥35+0 weeks who were born within 2 weeks of the maternal infection were matched 1:2 with a control group based on GA. The main outcomes were respiratory diseases, including transient tachypnea of the newborn (TTN), respiratory distress syndrome, meconium aspiration syndrome, the need for respiratory support, and length of hospital stay. Uni- and multivariate logistic regression analyses were performed and adjusted for relevant covariates, including maternal age, obstetric complications (hypertension and gestational diabetes), delivery mode, birth weight, sex, and small-for-gestational-age status. RESULTS: The case group comprised 103 neonates (mean GA, 38.5±1.3 weeks; mean birth weight, 3,121±397 g), while the control group included 206 neonates (mean GA, 38.4±1.2 weeks; mean birth weight, 3088±428 g). In the case and control groups, the proportion of cesarean sections was 91% and 40%, respectively, while the proportion of male infants was 56% and 47%, respectively. After adjusting for covariates, the case group had a higher risk of TTN (adjusted odd ratio [AOR], 3.69; 95% confidence interval [CI], 1.69-8.07), noninvasive respiratory ventilator use (AOR, 2.28; 95% CI, 1.05-4.97), and oxygen support (AOR, 4.83; 95% CI, 1.46-15.95). CONCLUSION: Newborns born to COVID-19-infected mothers are at increased risk of TTN and may require respiratory support. Close monitoring of respiratory symptoms is crucial in neonates.

Analysis of mutations in the XPD gene in a patient with brittle hair.

Trichothiodystrophy (TTD) is a rare, autosomal recessive, multisystem disorder characterized by sulfur-deficient brittle hair, growth and mental retardation, and ichthyosis. TTD is caused primarily by mutations in the xeroderma pigmentosum group D (XPD) gene, which encodes a subunit of the basal transcription factor IIH. We have identified a novel heterozygous mutation in XPD (c.1906C>T; p.R636W) resulting in mild-phenotype TTD in the proband and her mother. No identical variations were found in one hundred healthy Korean controls. In silico analysis suggested that the novel mutation was a causative mutation for TTD. This genotype-phenotype correlation provides a unique insight into the TTD inheritance pattern and could prove useful in the diagnosis of patients.

Development and diagnostic application/evaluation of pandemic (H1N1) 2009 influenza virus-specific monoclonal antibodies.

We prepared mAb specific to the H1N1 2009 virus (H1N1 2009) to facilitate development of an RDT with enhanced sensitivity and specificity. Among these antibodies, we identified two clones--hybridomas 1H7E1 and 3A3H7-that specifically bound to H1N1 2009 (non-seasonal) and were very suitable for application to a diagnostic kit. The affinity constants (K(a)) of 1H7E1 and 3A3H7 were 1.10 × 10(10) and 2.35 × 10(10), respectively. To identify the antibodies, we performed ELISA and immunoblot analyses and found that 1H7E1 recognized a conformational epitope of HA while 3A3H7 recognized a linear epitope. In clinical evaluations using specimens from 215 patients, a lateral flow rapid testing kit comprising these mAb showed a sensitivity of 81.5% (75/92) and a specificity of 96.7% (119/123). Results using the RDT kit were well correlated with conventional RT-PCR methods as commonly and commercially used. Based on our findings, we believe that use of these mAb with a rapid evaluation kit could serve as a good diagnostic tool for H1N1 2009.

Novel in-frame deletion mutation in FLCN gene in a Korean family with recurrent primary spontaneous pneumothorax.

Birt-Hogg-Dubé syndrome (BHDS) is an autosomal dominant disease presenting with skin fibrofolliculomas, pulmonary cysts, primary spontaneous pneumothorax (PSP), and renal cancer. It is caused by germline mutations in the FLCN gene, which encodes folliculin. Here we report a novel in-frame deletion mutation p.F143del (c.427_429delTTC) in exon 6 of FLCN gene in the proband and her two sisters. The proband was a 40-year-old Korean woman who presented with right-sided pneumothorax and papular lesions on the face and neck area but without renal cancer. Her father also had a history of PSP and died of renal cancer at the age of 75. Her older sisters have been treated for recurrent PSP but did not have skin lesions suspicious of fibrofolliculoma. The relative expression of FLCN was significantly reduced in the proband and one of the sibling who was confirmed to have FLCN mutation. In-frame deletions in the FLCN gene have rarely been reported but have been shown to impose significant effect on protein stability of FLCN. Identification of a novel genotype in BHDS will provide clues to the phenotype-genotype relations and may aid in explaining the molecular pathogenesis of diseases related to FLCN mutation.

A Gly1609Arg missense mutation in the vWF gene in a Korean patient with von Willebrand disease type 2A.

We describe a case of a c.4825G>A (p.Gly1609Arg [Gly846Arg]) missense mutation in the gene encoding von Willebrand factor (vWF) in a Korean patient with von Willebrand disease (vWD) type 2A. The proband is a 37-year-old female who suffers from dysmenorrhea and menorrhagia. On laboratory testing, we found a low (0.01) vWF:RCo/Ag ratio, a decrease in high and intermediate molecular weight multimers from plasma, and abnormalities in the collagen binding capacity of plasma vWF, all of which were indicative of vWD type 2. Family studies revealed that her sister, son, and daughter also had a low vWF:RCo/ Ag ratio and a decrease in high molecular weight multimers from plasma. Genetic analyses showed that she and her three family members had the same heterozygous c.4825G>A (p.Gly1609Arg [Gly846Arg]) missense mutation. To our knowledge, this is the first report of the c.4825G>A (p.Gly1609Arg [Gly846Arg]) heterozygote mutation in Korean family members with vWD type 2A.

Heterogeneous lengths of copy number mutations in human coagulopathy revealed by genome-wide high-density SNP array.

BACKGROUND: The recent advent of genome-wide molecular platforms has facilitated our understanding of the human genome and disease, particularly copy number aberrations. We performed genome-wide single nucleotide polymorphism-array in hereditary coagulopathy to delineate the extent of copy number mutations and to assess its diagnostic utility. DESIGN AND METHODS: The study subjects were 17 patients with hereditary coagulopathy from copy number mutations in coagulation genes detected by multiple ligation-dependent probe amplification. Eleven had hemophilia (7 hemophilia A and 4 hemophilia B) and 6 had thrombophilia (4 protein S deficiency and 2 antithrombin deficiency). Single nucleotide polymorphism-array experiments were performed using Affymetrix Genome-Wide Human SNP arrays 6.0. RESULTS: Copy number mutations were identified by single nucleotide polymorphism-array in 9 patients, which ranged in length from 51 Kb to 6,288 Kb harboring 2 to ~160 genes. Single nucleotide polymorphism-array showed a neutral copy number status in 8 patients including 7 with either a single-exon copy number mutation or duplication mutations of PROS1. CONCLUSIONS: This study revealed unexpectedly heterogeneous lengths of copy number mutations underlying human coagulopathy. Single nucleotide polymorphism-array had limitations in detecting copy number mutations involving a single exon or those of a gene with homologous sequences such as a pseudogene.

Development and evaluation of a rapid diagnostic test for Plasmodium falciparum, P. vivax, and mixed-species malaria antigens.

Plasmodium falciparum and P. vivax malaria are endemic to many parts of the world and humans can be co-infected with both species. Because each Plasmodium species has different biological and clinical characteristics, accurate differentiation of the infecting species is essential for effective treatment. Therefore, we produced three monoclonal antibodies that recognize the lactate dehydrogenase of P. falciparum, P. vivax, or both to develop the first P. falciparum, P. vivax, and mixed-species infections malaria antigen detection kit. The detection limits of this kit were 150 and 250 parasites/µL for P. falciparum and P. vivax, respectively, and the kit was able to detect mixed-species infections. The sensitivity and specificity of this kit was assessed with 722 clinical specimens. Our results showed that its sensitivities for P. falciparum, P. vivax, and mixed-species infection were 96.5%, 95.3%, and 85.7%, respectively. In addition, its specificity was high (99.4%).

A rare splicing mutation in the PROS1 gene of a Korean patient with type I hereditary protein S deficiency.

Hereditary protein S (PS) deficiency (Gene ID: 5627; MIM # 176880) is a notable risk factor for recurrent venous thrombosis, inherited as an autosomal-dominant trait, either homozygous or heterozygous. It may be caused by point mutations in the gene (PROS1) encoding PS, which contains 15 exons on the chromosome 3q11.2. Only a few point mutations associated with the PROS1 gene in patients with hereditary PS deficiency have been reported. A 60-year-old woman was admitted for deep vein thrombosis (DVT) of the right lower extremity. Upon coagulation examination, both the free PS antigen level and the total PS antigen level were decreased, so the DNA-PCR products of all 15 exons, including the exon-intron boundaries of the PROS1, gene were directly sequenced. A substitution from guanine to adenine at position +5 of the donor splice site of intron 10 (c.1155+5G>A) was identified. Further familial study was performed, and the patient's older sister was revealed to have the same mutation; she was already taking warfarin due to diagnosed pulmonary thromboembolism. Here we report a G to A transition at position +5 of intron 10 from the splice donor site as a rare case of a patient with type I hereditary PS deficiency in Korea.

Rapid identification of thrombocytopenia-associated multiple organ failure using red blood cell parameters and a volume/hemoglobin concentration cytogram.

Thrombocytopenia-associated multiple organ failure (TAMOF) has a high mortality rate when not treated, and early detection of TAMOF is very important diagnostically and therapeutically. We describe herein our experience of early detection of TAMOF, using an automated hematology analyzer. From 498,390 inpatients, we selected 12 patients suspected of having peripheral schistocytosis, based on the results of red blood cell (RBC) parameters and a volume/hemoglobin concentration (V/HC) cytogram. We promptly evaluated whether the individual patients had clinical manifestations and laboratory findings were consistent with TAMOF. Plasma exchanges were then performed for each patient. All 12 patients had TAMOF. The mean values of RBC parameters were significantly higher in all of the patients than with the reference range, however, 3 patients had % RBC fragments within the reference range. The mean value of ADAMTS-13 activity was slightly lower in patients compared with the reference range. Of the 12 patients, remission was obtained in 9 patients (75%) within 4 to 5 weeks using plasma exchanges. Three patients died. An increased percentage of microcytic hyperchromic cells with anisocytosis and anisochromia indicated the presence of schistocytes, making it an excellent screening marker for TAMOF. Identification of TAMOF with RBC parameters and a V/HC cytogram is a facile and rapid method along with an automated hematology analyzer already in use for routine complete blood cell counting test.

A heparin binding site Arg79Cys missense mutation in the SERPINC1 gene in a Korean patient with hereditary antithrombin deficiency.

We describe a case of heparin binding site Arg79Cys mutation in the gene encoding antithrombin, SERPINC1, in a Korean patient with hereditary antithrombin (AT) deficiency. The patient was a 34-year-old Korean man who presented with deep vein thrombosis (DVT) in his right leg without precipitating factors. On outpatient evaluation, coagulation tests without anticoagulation revealed a decreased AT III activity level at 48%, but normal AT III antigen level at 103%, indicating type II AT deficiency. Family studies revealed that his father (62 years of age) had decreased AT activity (48%) but had normal AT antigen levels (116%), indicating that the proband had a paternally inherited type II AT deficiency. Direct sequencing of the SERPINC1 gene in the patient and his father revealed a heterozygotic missense mutation, a cytosine to thymine substitution at nucleotide position 235 in exon 2 of the SERPINC1 gene (p.Arg79Cys). To our knowledge, this is the first report of Arg79Cys heterozygote mutation in family members with venous thromboembolism.

A novel mutation in the MECP2 gene in a Korean patient with Rett syndrome.

Rett syndrome (RTT) is a severe X-linked dominant neurodevelopmental disorder. Mutations in the MECP2 gene on chromosome Xq28 have been shown to be the cause of RTT. Using DNA samples from a RTT patient and her parents, we sequenced three exons and flanking intron regions of the MECP2 gene using the polymerase chain reaction. Sequencing of the MECP2 gene in the proband revealed a novel 41-base pair deletion in exon 4 (c.1152_1192del41). This mutation resulted in premature termination of the 487 amino acid protein at the 390th codon, predicting a partial loss of the C-terminal domain. We did not observe this mutation in either parent of the RTT patient, but further studies are needed to evaluate the possibility of germline mosaicism.

Evaluation of a rapid diagnostic test, NanoSign® Influenza A/B Antigen, for detection of the 2009 pandemic influenza A/H1N1 viruses.

BACKGROUND: This study evaluated the clinical accuracy and analytical sensitivity of the NanoSign® Influenza A/B antigen kit in detecting 2009 pandemic influenza A/H1N1 viruses. The kit is one of the most popular rapid diagnostic tests for detecting influenza in Republic of Korea. RESULTS: The NanoSign® Influenza A/B kit resulted in 79.4% sensitivity and 97.2% specificity compared to RT-PCR in the detection of the viruses from 1,023 specimens. In addition, the kit was able to detect two strains of novel influenza viruses, Influenza A/California/12/2009(H1N1) and clinically isolated wild-type novel influenza A/H1N1, both of which are spreading epidemically throughout the world. In addition, the correlation between NanoSign® Influenza A/B test and conventional RT-PCR was approximately 94%, indicating a high concordance rate. Analytical sensitivity of the kit was approximately 73 ± 3.65 ng/mL of the purified viral proteins and 1.13 ± 0.11 hemagglutination units for the cultured virus. CONCLUSIONS: As the NanoSign® Influenza A/B kit showed relatively high sensitivity and specificity and the good correlation with RT-PCR, it will be very useful in the early control of influenza infection and in helping physicians in making early treatment decisions.

Analysis of fluorescence in situ hybridization, mtDNA quantification, and mtDNA sequence for the detection of early bladder cancer.

We designed this study to test the sensitivities of cytology, the nuclear matrix protein 22 (NMP22) assay, and fluorescence in situ hybridization (FISH) in the early detection of urothelial carcinoma, and to identify mtDNA alterations in urinary epithelial cells. We collected 41 urine samples and 26 corresponding peripheral blood samples from patients with clinically suspected urothelial carcinoma. The FISH and NMP22 assays detected 92.1% of the cancers, and cytology detected 60.5%. In the low-grade group, NMP22 and FISH analyses were more sensitive than cytology, but in the high-grade group, all three methods showed approximately 90% sensitivity. Overall, the FISH and NMP22, or FISH and cytology assays combined detected 97.4% of cancers, while cytology with NMP22 detected 92.1%. In the low-grade group, the sensitivity of the three methods combined was above 80%, but in high-grade group, the combined sensitivity was approximately 100%. In the mtDNA control region, we detected characteristic heteroplasmic mtDNA substitution mutations in 1 patient and a mtDNA length heteroplasmic mutation in 303 polyC or 16184 poly C in 20 patients. Overall, urothelial carcinoma-specific mtDNA mutations were observed in 20 of the 26 patients (76.9%). The average mtDNA copy numbers in urine samples and corresponding peripheral blood samples (83.45 +/- 60.36 and 39.0 +/- 24.38, respectively) (mean +/- standard deviation [SD]) differed significantly (P < 0.001). The mtDNA copy numbers in the urine samples from patients with high-grade and low-grade tumors (81.83 +/- 67.78 and 86.49 +/- 46.69, respectively) did not differ significantly (P = 0.589). In conclusion, the FISH assay showed the highest sensitivity for detecting low-grade urothelial carcinoma, and mtDNA copy numbers in urine samples were higher than those in the corresponding peripheral blood samples. The frequency of mtDNA mutations in the D-loop region in patients with cancer was approximately 80% in our study. This report further supports the significance of genetic alteration in urothelial carcinoma and the clinical utility of the FISH, mtDNA quantitation polymerase chain reaction, mtDNA sequencing, and capillary electrophoresis for this purpose.

Automated detection of malaria-associated pseudoeosinophilia and abnormal WBC scattergram by the Sysmex XE-2100 hematology analyzer: a clinical study with 1,801 patients and real-time quantitative PCR analysis in vivax malaria-endemic area.

Recently, the XE-2100 hematology analyzer was investigated in a rather small patient group; pseudoeosinophilia or abnormal white blood cell (WBC) scattergrams reported by this instrument were considered as significantly valuable diagnostic parameters in detecting vivax malaria. This study was conducted not only to assess the usefulness of pseudoeosinophilia or abnormal WBC scattergram in vivax malaria-endemic areas with large patient groups (N = 1,801) but also to investigate the correlation of parasitemia and platelet count with pseudoeosinophilia and abnormal WBC scattergrams. Of the 1,801 analyzed patients, 413 (22.9%) were found to have malaria by Wright-Giemsa stained blood smears. Overall, either pseudoeosinophilia or abnormal WBC scattergram was detected in 191 of 413 malaria patients and 4 of 1,388 patients without malaria (sensitivity = 46.2%, specificity = 99.7%). We suggest that clinical hematology laboratories using the XE-2100 analyzer should be aware of such specific parameters, even with the absence of a clinical request.

Oxidative status in iron-deficiency anemia.

Oxidative stress is an imbalance between free radicals and antioxidant molecules that can play an important role in the pathogenesis of iron-deficiency anemia (IDA). The aim of this study was to investigate oxidative status in patients with IDA and alteration of oxidative status after iron treatment. Thirty-three female patients with IDA and 25 healthy controls were included in this study. Oxidant and total antioxidant capacity were determined using free oxygen radicals test and free oxygen radicals defence (Form CR 3000, Callegari, Parma, Italy). Catalase activity was measured by spectrophotometer using a commercially available kit (Bioxytech Catalase-520, OxisResearch, Portland, OR). Oxidant activity in patients with IDA was significantly higher than controls (P<0.05), while total antioxidant and catalase activity were significantly lower (P<0.05). After treatment, oxidant, antioxidant, and catalase activity reached the levels of the control group, and no significant differences were observed among groups (P>0.05). In conclusion, our data indicate that blood reactive oxygen species was lower and total antioxidant and catalase activity were higher after rather than before treatment in patients with IDA. The results of our study support the higher oxidative stress hypothesis in IDA; however, due to the limited number of cases included, more studies may be required to confirm the results.

Chronic myelomonocytic leukemia with der(9)t(1;9)(q11;q34) as a sole abnormality.

The chromosomal abnormality der(9)t(1;9)(q11;q34) is a rare occurrence in patients with hematologic malignancies. As far as we know, only 3 cases of acute myeloid leukemia, 1 case of polycythemia vera, and 1 case of multiple myeloma with this derivative chromosome have been reported in the literature. Here we report the first case of der(9)t(1;9)(q11;q34) in a patient with chronic myelomonocytic leukemia (CMML). A 45-yr-old man was brought to our hospital for evaluation of pancytopenia and monocytosis. The patient's persistent monocytosis in peripheral blood and his bone marrow findings were consistent with the diagnosis of CMML. Chromosome study results repeatedly showed 46,XY,der(9)t(1;9)(q11;q34). In addition, the BCR/ABL fluorescent in situ hybridization (FISH) pattern of the interphase cells was interpreted as: "nuc ish(ABL, BCR) x 2[292/300]," consistent with the normal signal patterns found in 97% of the nuclei examined. For further evaluation, multi-color FISH (mFISH) analysis was performed and it showed the distinct unbalanced derivative chromosome der(9)t(1;9)(q11;q34) in 5 metaphase cells analyzed. Not only does this show an extraordinary type of trisomy 1q, but it reveals a rare recurrent case of der(9)t(1;9)(q11;q34) in patients with monocytic-lineage leukemia. Further studies are needed to evaluate the prognosis, survival, and treatment response of such patients with der(9)t(1;9)(q11;q34).

JAK2 V617F/C618R mutation in a patient with polycythemia vera: a case study and review of the literature.

The acquired Janus kinase 2 (JAK2) V617F mutation shows a high frequency in diverse BCR/ABL-negative chronic myeloproliferative disorders (CMPD), and it is typically associated with polycythemia vera (PV). The frequency of JAK2 V617F mutation is about 90% in patients with PV, 50-60% in patients with essential thrombocythemia (ET), primary myelofibrosis (PMF), and less in patients with other myeloid neoplasms, while extremely rare in lymphoid malignancies. About 20 kinds of novel mutations of JAK2 other than V617F have been reported recently in the literature. Among these mutations, only one case of JAK2 V617F/C618R has been reported in a 67-year-old patient with PV. Here, we report a rare case of JAK2 V617F/C618R in a 41-year-old Korean male patient with review of the relevant literature on JAK2 mutations other than V617F. Although the frequency of JAK2 mutations other than the V617F is very low, this study emphasizes the need for assiduous analysis of the JAK2 gene to characterize new mutations, to determine their frequency, and to improve understanding of the clinical phenotypes as well as prognostic and biologic features associated with these mutations.

A novel de novo mutation in the serine-threonine kinase STK11 gene in a Korean patient with Peutz-Jeghers syndrome.

BACKGROUND: Peutz-Jeghers syndrome (PJS) is an unusual autosomal dominant disorder characterized by mucocutaneous pigmentation and multiple gastrointestinal hamartomatous polyps. Patients with PJS are at an increased risk of developing multi-organ cancer, most frequently those involving the gastrointestinal tract. Germline mutation of the STK11 gene, which encodes a serine-threonine kinase, is responsible for PJS. METHODS: Using DNA samples obtained from the patient and his family members, we sequenced nine exons and flanking intron regions of the STK11 gene using polymerase chain reaction (PCR) and direct sequencing. RESULTS: Sequencing of the STK11 gene in the proband of the family revealed a novel 1-base pair deletion of guanine (G) in exon 6 (c.826delG; Gly276AlafsX11). This mutation resulted in a premature termination at codon 286, predicting a partial loss of the kinase domain and complete loss of the C-terminal domain. We did not observe this mutation in both parents of the PJS patient. Therefore, it is considered a novel de novo mutation. CONCLUSION: The results presented herein enlarge the spectrum of mutations of the STK11 gene by identifying a novel de novo mutation in a PJS patient and further support the hypothesis that STK11 mutations are disease-causing mutations for PJS with or without a positive family history.