Experience at Department of Laboratory Medicine during the COVID-19 Outbreak in Daegu / 대한임상미생물학회지

The first case of coronavirus disease 2019 (COVID-19) in Korea was reported in January 2020.As the secondary transmissions accelerated within the country, the government revised the outbreak alert for COVID-19 from attention to caution. Mid-February, when a massive outbreak was reported from a church in Daegu, our institution initiated testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). More than 300 laboratory tests were performed within the first 2 months, before the number of cases began to decline. Here, we describe our experience of 4 months at the department of Laboratory Medicine, Keimyung University Dongsan Hospital, located in Daegu, where a massive COVID-19 outbreak occurred.

Experience at Department of Laboratory Medicine during the COVID-19 Outbreak in Daegu / 대한임상미생물학회지

The first case of coronavirus disease 2019 (COVID-19) in Korea was reported in January 2020.As the secondary transmissions accelerated within the country, the government revised the outbreak alert for COVID-19 from attention to caution. Mid-February, when a massive outbreak was reported from a church in Daegu, our institution initiated testing for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). More than 300 laboratory tests were performed within the first 2 months, before the number of cases began to decline. Here, we describe our experience of 4 months at the department of Laboratory Medicine, Keimyung University Dongsan Hospital, located in Daegu, where a massive COVID-19 outbreak occurred.

Amino Acid-Based Formula in Premature Infants with Feeding Intolerance: Comparison of Fecal Calprotectin Level / 대한소아소화기영양학회지

PURPOSE: We investigated fecal calprotectin (FC) levels in preterm infants with and without feeding intolerance (FI), and compared the FC levels according to the type of feeding. METHODS: The medical records of 67 premature infants were reviewed retrospectively. The fully enteral-fed infants were classified into two groups; the FI group (29 infants) and the control group (31 infants). Seven infants with necrotizing enterocolitis, sepsis, and perinatal asphyxia were excluded. If breast milk (BM) or preterm formula (PF) could not be tolerated by infants with FI, amino acid-based formula (AAF) was tried temporarily. Once FI improved, AAF was discontinued, and BM or PF was resumed. We investigated the FC levels according to the type of feeding. RESULTS: Significant differences were found in gestational age, birth weight, age when full enteral feeding was achieved, and hospital stay between the FI and control group (p 0.05). CONCLUSION: The FC levels in AAF-fed infants with FI showed significantly lower than those in the BM- or PF-fed infants with FI. The mitigation of gut inflammation through the decrease of FC levels in AAF-fed infants with FI could be presumed.

The relationship between anti-C-reactive protein and disease activity in patients with systemic lupus erythematosus

BACKGROUND/AIMS: Anti-C-reactive protein (CRP) antibody has been introduced as a potential biologic marker in Systemic lupus erythematosus (SLE). The aim of study is to evaluate the level of anti-CRP antibody in patients with SLE. METHODS: This study investigated the relationship between levels of anti-CRP antibodies and disease activity markers, such as complement, anti-double-stranded DNA antibody, and SLE disease activity index in 34 patients with SLE. RESULTS: The serum anti-CRP antibody levels of the patients with SLE were significantly higher than those of the healthy controls (11.3 ± 5.6 µg/mL vs. 9.1 ± 2.8 µg/mL). The percentages of the positive anti-CRP antibody were 52.9% in SLE and 27.8% in controls. Disease duration of SLE showed significant correlation with the anti-CRP antibody (r = 0.234, p = 0.026). However no significant relationship was observed between the levels of anti-CRP antibodies and disease activity markers. CONCLUSIONS: These data show that the anti-CRP antibody levels of the patients with SLE were significantly higher than those of healthy controls. We observed that the presence of the anti-CRP anti-CRP antibody was not associated with disease activity of SLE.

A Case of Partial Trisomy 15q25.3-qter / 대한진단검사의학회지

A 15q25-qter partial trisomy characterized by pre or postnatal overgrowth, tall stature, macrocephaly and craniosynostosis has rarely been reported. The cause of overgrowth has been thought to be the triplication of the insulin-like growth factor 1 receptor (IGF1R) gene located on the 15q26.3. We report a patient with partial trisomy 15q25.3-qter showing mental retardation, developmental delay, macrocephaly, long narrow face, ptosis, high palate arch, scoliosis, clinodactyly and overgrowth. Additional material located on terminal 2q was found in karyotyping analysis. In bacterial artificial chromosome (BAC) clone-based-array comparative genomic hybridization (aCGH) analysis, a gain of 31 clones on 15q25.3-qter and a loss of 2 clones on 2q37.3 were observed. An extra copy of IGF1R gene was observed on derivative chromosome 2 in FISH analysis. In conclusion, the patient was diagnosed to have de novo 46,XX,der(2)t(2;15)(q37.3;q25.3) chromosome complement. Adequate genetic counseling and regular follow-ups would be needed for the patient.

A Case of Atypical CML with Micro BCR/ABL Rearrangement

Microtype BCR/ABL rearrangement is extremely rare and has been known to be associated with neutrophilic chronic myeloid leukemia (N-CML). However, there is more to be understood regarding this phenotype. We report a case of atypical CML that exhibited micro BCR/ABL rearrangement with predominant thrombocytosis. Our patient showed thrombocytosis (1,464x10(9)/L) and megakaryocytosis in the peripheral blood and bone marrow. However, neither leukocytosis nor neutrophilia was observed (white blood cells (WBC), 5.02x10(9)/L neutrophils, 45%). Bone marrow aspirate revealed increased cellularity: 12% basophils, 6% eosinophils, and 9% blasts. The 46,XX,t(9;22)(q34;q11.2),i(17q) chromosome complement was observed in 4 of 20 metaphase cells, and standard BCR/ABL fusion signals were observed in 10% of interphase cells on fluorescence in situ-hybridization (FISH) analysis. Reverse transcriptase- polymerase chain reaction (RT-PCR) was used to acquire the BCR/ABL fusion transcript, the identity of which was confirmed via sequence analysis. Hematologic remission was achieved 2 months after imatinib therapy initiation, and molecular remission was achieved 2 months after hematologic remission. The patient is currently undergoing regular follow-up visits and is in good health. However, further long-term follow up is warranted. The incorporation of imatinib into therapeutic strategies may be further established through the study of more cases of micro BCR/ABL.

GATA1 Mutation in Transient Myeloproliferative Disorder of Down Syndrome

Children with Down syndrome (DS) have a higher risk of developing leukemia than do healthy children, and they especially have a higher risk for developing transient myeloproliferative disorder (TMD) or acute megakaryocytic leukemia (AMKL). In recent studies, it has been reported that most of these patients have acquired mutation of the GATA1 gene, which encodes the erythroid/megakaryocytic transcription factor GATA1. GATA1 mutations have not been found in AMKL patients who did not have DS and other hematologic malignancies in DS. Most of the GATA1 mutations in DS-TMD/AMKL are nonsense mutations that are mainly located in exon 2. We observed a nonsense mutation in exon 2 of GATA1 [c.189_190delCA (Tyr63X)] in one case of DS-TMD. The GATA1 mutation has been thought to be an early event in the leukemogenesis of DS-TMD/AMKL and it could be used as a stable molecular marker to assess the treatment response or to monitor for the recurrence of DS-TMD/AMKL.

Measurement of the Residual Leukocyte Count by Flow Cytometry in Leukocyte-reduced Blood Components / 대한수혈학회지

BACKGROUND: Counting methods for residual leukocytes in leukocyte-reduced blood components include the manual assay using a Nageotte hemocytometer, flow cytometry (FCM) and polymerase chain reaction (PCR). The Nageotte hemocytometer is the most widely used technique in Korea, but it is time consuming and dependent upon the skill of the examiner. We examined residual leukocytes count using a hemocytometer and FCM and compared the accuracy of the use of both methods. METHODS: Twenty units of RBC concentrates (RCs) were collected in quadruple top-to-bottom collection bags of the Green Cross (Green Cross, Eumsung, Korea) and from BD (Becton Dickinson Korea, Gumi, Korea). Thirty-five units of single donor platelets (SDPs) collected by Amicus (Baxter, Deerfield, IL USA), MCS+ (Haemonetics, Braintree, MA, USA) and Trima (Gambro BCT, Lakewood, CO, USA) were used to measure residual leukocytes using a hemocytometer and FCM using the LeucoCOUNT system (BD Bioscience, San Jose, CA USA). RESULTS: Linearity of the LeucoCOUNT system was well maintained (R2=0.9998). Reproducibility was CV of 5.08% for 53.01/microlitermicroliter and 8.54% for 4.97/microliter. The hemocytometer measured lower leukocyte counts in all RCs and SDPs than the LeucoCOUNT system. The mean residual leukocyte counts in RCs measured by the hemocytometer were 0.075x10(6)/unit with the Green Cross collection bags and 0.067x10(6)/unit with the BD collection bags, but were 2.301x10(6)/unit and 1.943x10(6)/unit, respectively, when measured with use of the LeucoCOUNT system. The mean residual leukocyte count in the SDPs collected by Amicus, MCS+ and Trima, as measured by the hemocytometer, were 0.037x10(6)/unit, 0.046x10(6)/unit and 0.043x10(6)/unit, respectively. The mean residual leukocyte count in the SDPs collected by Amicus, MCS+ and Trima, as measured by the LeucoCOUNT system, were 0.061x10(6)/unit, 0.161x10(6)/unit and 0.045x10(6)/unit, respectively. CONCLUSION: The use of the flow cytometric method is moresensitive and produces an accurate leukocyte count in leukocyte-reduced blood components than the use of themanual method.

A RhD Negative Patient Failed to Produce Detectable Anti-D after Transfusion of 35 Units of RhD Positive Red Blood Cells / 대한진단검사의학회지

In the present day, pretransfusion tests include ABO and RhD grouping, antibody screening, antibody identification, and cross matching. Although error rates for these tests have decreased compared to those in the past, clerical errors still occur. When exposed to RhD positive RBCs, a RhD negative person can produce anti-D that causes a severe hemolytic disease of the fetus and the newborn in addition to hemolytic transfusion reactions. Therefore, administration of RhD positive RBCs to a RhD negative person should be avoided. We experienced a RhD negative patient who had been misidentified as positive and transfused 35 units of RhD positive RBCs eight years ago, but did not have detectable anti-D in present. The red cells of the patient showed no agglutination with the anti-D reagent and a negative result in the standard weak D test. The multiplex PCR with sequence-specific priming revealed that the patient was RhD negative.

mRNA Expression and RNA Editing (2451 C-to-U) of IL-12 Receptor beta2 in Adult Atopic Patients

Interleukin (IL)-12 activates T helper (Th) 1 cells to produce interferon (IFN)-gamma which inhibits atopic inflammation. IL-12 acts through interaction with its receptor, especially beta2 subunit. In several studies, the low production of IFN-gamma in peripheral mononuclear cells of atopic patients on response to IL-12 stimulation has been reported. Therefore we investigated the IL-12 receptor beta2 (IL-12R beta2) mRNA expression and RNA editing, nucleotide 2451 C-to-U conversion, to find the cause of low responsiveness to IL-12 in atopy. Quantitative real time PCR for mRNA expression and sequence analysis for RNA editing were performed in 80 atopic patients and 54 healthy controls. The expression of IL-12R beta2 mRNA was significantly lower in atopic patients than healthy controls (p<0.05). In sequence analysis, RNA editing on nucleotide 2451 was not found from either atopic patients or healthy controls. In additional evaluation, there was no relationship between expression of IL-12R beta2 mRNA and serum total IgE or blood eosinophil count. Reduced IL-12R beta2 mRNA expression in atopic patients indicate the reduced capacity to respond to IL-12 which induce IFN-gamma production and this may contribute to Th2-skewed immune response in atopy.

A case of Corynebacterium xerosis Infection in Cerebrospinal Fluid and Ventriculoperitoneal Shunt / 대한임상미생물학회지

Corynebacterium xerosis is a normal flora of the skin, mucous membrane and gastrointestinal tract. Although not usually considered to be a pathogen, it occasionally causes serious infections in immunocompromised hosts. We report a case of a shunt infection by C.xerosis developed in a 58-year-old woman following the insertion of a ventriculoperitoneal shunt. The organism was also isolated from the cerebrospinal fluid and blood. The isolate was resistant to most of the antibiotics tested except for vancomycin. However, in spite of treatment with vancomycin, the patient was expired after 5 months.

A Case of Skin and Soft Tissue Infection by Mycobacterium abscessus / 대한임상미생물학회지

A 36-year-old female who initially presented with a small erythematous and swollen abscess on her left anterior tibial area was found out to have a cutaneous Mycobacterium abscessus infection. She was first treated with incision and drainage, dressing, and antibiotics. The lesion began to be aggravated and dispersed. Neither aerobic nor anaerobic bacteria was grown on blood agar plate. After a few weeks, Mycobacterium grew on Ogawa media after 6 days, and was identified as M. abscessus by PCR-restriction fragment length polymorphism. She was then treated with clarithromycin, levofloxacin, and amikacin, and the skin lesion was resolved without further recurrence.