Autosomal dominant chronic mucocutaneous candidiasis (AD-CMC) is a subtype of CMC caused by gain-of-function (GOF) mutation of the signal transducer and the activator of transcription 1 (STAT1) protein. GOF mutation of STAT1 disrupts Th17 cell differentiation and causes susceptibility to candida infection in mucous membranes. Although genetic testing is crucial to diagnose AD-CMC, a simple and fast diagnostic tool is required for the management and reduction of complications associated with infection. Flow cytometry (FCM) is suggested for the measurement of intracellular phosphorylated STAT1 (pSTAT1) in a stimulated status. Here, we report the application of FCM to show the activation status of STAT signaling in a 24-year-old female patient diagnosed with AD-CMC. Compared to the controls, the patient’s T cells showed increased levels of pSTAT1 after stimulation by interferon-γ and lesser extent of inhibition caused by an inhibitor. To the best of our knowledge, this is the first evaluation of the usefulness of FCM as an alternative diagnostic and monitoring tool of GOF STAT1 in Korea.

Hu5F9-G4, an immunoglobulin 4 (IgG4) monoclonal humanized antibody targeting CD47, is under active clinical trials as a novel immunotherapeutic for hematologic and solid malignancies and can cause pretransfusion testing interference. In this study, we demonstrate our first experience of Hu5F9-G4 interference with serologic testing and mitigate this interference through multiple platelet alloadsorption. A 69-year-old woman with a history of ureter cancer presented with anemia. On routine blood group typing, the patient showed strong agglutination (4+) with anti-A, A, and B cells. Unexpectedly, antibody screening and identification showed panreactivity to all panel cells, although the autocontrol result was negative. Medical records revealed that she was enrolled in an anti-CD47 clinical trial. To eliminate interference by the drug, we attempted alloadsorption using pooled platelets that were prepared from segments of random single donor platelets. After seven alloadsorption sessions using pooled allogeneic platelets, the ABO discrepancy and panreactivity was resolved. To our knowledge, this is the first demonstration of anti-CD47 interference elimination in Korea.

Weak D and partial D result in quantitative and qualitative changes in RhD protein expression respectively. It is difficult to discriminate weak D from partial D by serological tests alone. RHD genotyping is a useful method that complements serological results. A 64-year-old woman visited our hospital for microvascular decompression surgery. Her blood type was O, D negative by manual tube test and as per auto analyzer results (QWALYS-3 system; DIAGAST, France). Weak D and partial D tests were performed by using two different monoclonal anti-D reagents (Bioscot; Merck Millipore, UK; Bioclone; Ortho Clinical Diagnostics, USA) and a panel of nine monoclonal antibodies, including anti-D IgM and IgG (D-Screen; DIAGAST, France). However, these serological tests could not confirm the subtype of partial D. Therefore, sequencing of RHD exon 1 to 10 was additionally performed for the patient and the case was revealed to be partial DVI type 3.

Emergence of new clonal chromosomal abnormality (CCA) has been reported in Philadelphia-negative cells in patients with chronic myeloid leukemia (CML) undergoing the tyrosine kinase inhibitor (TKI) treatment. However, the time of emergence and clinical significance of CCA remains to be elucidated. In this study, we report a CML patient undergoing TKI treatment who developed myelodysplastic syndrome (MDS) after 206 months since the diagnosis of CML. Results of droplet digital PCR performed with serial bone marrow samples revealed that monosomy 7 in Philadelphia-negative cells appeared at the time of MDS development that did not exist initially at the time of CML diagnosis.

Flow cytometry is a powerful tool for analysis of hematologic malignancies, that provides rapid, quantitative, and multiparametric analysis of heterogeneous cell populations, but requires standardization because of complexities in panel design and interpretation. Here, we compared the Plasma Cell Screening Tube (PCST) kit (Cytognos, Spain) in conjunction with EuroFlow antibody panels for standardization of flow cytometry to a conventional method for diagnosis of plasma cell dyscrasias. Thirty-nine bone marrow samples and one peripheral blood sample from 40 patients were tested. Thirty-three patients were diagnosed with multiple myeloma (MM), and seven were in a reactive state. In PCST implementation, eight antibodies were used for staining, including anti-CD45-Pacific Blue, anti-CD19-PECy7, anti-CD138-OC515, anti-CD38-FITC, anti-CD56-PE, anti-β2-microglobulin-PerCPCy5.5, anti-kappa-APC, and anti-lambda-APC-C750. Plasma cells were initially identified using CD38 and CD138; thereafter, CD38+, CD138+ gated cells were analyzed for CD56, CD19, CD45, cytoplasmic kappa, cytoplasmic lambda, and β2-microglobulin. Conventional flow cytometry was performed with six monoclonal antibodies, including anti-CD56-FITC, anti-kappa-FITC, anti-CD19-PE, anti-lambda-PE, anti-CD138-PECy5, and anti-CD45-PECy7 (Beckman Coulter, USA). Monoclonal plasma cells with cytoplasmic light-chain restriction were detected in 30 of 33 (90.9%) MM cases by conventional methods, and 32 of 33 (97.0%) MM cases with the PCST method. No differences were noted between PCST and the conventional method in immunophenotyping and plasma cell percentages (P=0.323). Among plasma cells, levels (%) were significantly higher by the PCST approach than those in the conventional method (97.6% vs 95.8%, P=0.010). PCST exhibited better performance for plasma cell dyscrasias diagnosis, and could improve laboratory efficiency and quality.

There are more than 10 million visits to primary care clinics annually due to pharyngitis or tonsillitis. The antibiotic prescription rate for these patients is more than 50%. An optimal diagnosis is necessary to avoid antibiotic misuse or overuse. Here, we compared the benefits and pitfalls of three currently available laboratory methods, such as throat culture, rapid antigen detection test (RADT), and molecular tests. We also reviewed the current American and Korean guidelines for bacterial pharyngitis. Although throat culture is regarded as a gold standard, it requires high technical expertise and culture facilities. In addition, the turn-around time (TAT) is 1 day-2 days causing possible inadequate prescription as well as the inconvenience of a second clinical visit to check results. The RADT does not require culture facilities and the TAT is noticeably short (5-10 min). The initial low sensitivity of the RADT has been improved these days. Though molecular tests are the most advanced, there remains a lack of clinical data. Therefore, we recommend judicious use of the RADT for diagnosing bacterial pharyngitis as well as effective antibiotic prescriptions at primary care clinics.

Background: Multiple Allergo-Sorbent Test (MAST) allows simultaneous detection of specific IgE antibodies using multiple allergens, and it is commonly used for allergy screening. Phadiatop assay (Phadia AB, Sweden), including Phadiatop test and Phadiatop Infant test, is a variant of specific IgE test that covers a mixture of common allergens. We compared the clinical utility of Phadiatop assay with that of the MAST AlloScreen (LG Life Science, Korea). Methods: A total of 218 samples classified by AlloScreen results were collected. Phadiatop test was performed on sera from 61 and 103 aeroallergen-positive and -negative subjects. Phadiatop Infant test was performed on sera from 54 and 103 food and aeroallergen-positive and -negative subjects. When the results of AlloScreen and Phadiatop assay were not identical, we confirmed them using ImmunoCAP (Phadia AB). Results: The concordance rate between AlloScreen and Phadiatop test was 93.2% (κ=0.86, P<0.001). Eleven (6.7%) of 164 specimens showed discrepant results. The results of AlloScreen did not agree with those of ImmunoCAP. The concordance rate between AlloScreen and Phadiatop Infant test was 97.4% (κ=0.945, P <0.001). Four (2.5%) specimens showed negative results in AlloScreen and positive results in Phadiatop Infant test. Three cases were confirmed as positive and one case was not confirmed through ImmunoCAP. Conclusions There was excellent agreement between AlloScreen and Phadiatop assay. Phadiatop assay accurately detected sensitization to common food and aeroallergen mixes. Therefore, Phadiatop assay is recommended as a screening test for allergic diseases.

Background: Detection of anti-human leukocyte antigen (HLA) antibodies is important during the selection of an appropriate donor prior to organ transplantation and also for monitoring the patients after transplantation. In this study, we compared antibodies detected via C3d assays, which monitors C3d complement-binding activities of HLA antibodies with those detected via single antigen bead (SAB) assays. Methods: A total of 66 serum samples were tested in parallel by SAB assays (Immucor Transplant Diagnostics, USA) and C3d assays (Immucor) for the detection of HLA class II antibodies. The relationship between these two methods was analyzed based on the types, numbers, median fluorescent intensity (MFI) values, and positivity of the antibodies using MATCH IT! Antibody (Immucor) program. Results: The number of antibodies obtained based on SAB and C3d assays was the highest with 24 samples (36.4%) in the 11–20 range and 23 (34.8%) in the 2–5 range detected via each assay. Among the SAB-positive antibodies, only 28 (6.4%) of the 440 antibodies with MFI ≤3,000 were C3d-positive, and 341 (61.3%) of the 556 antibodies with MFI ≥3,001 were C3d-positive. Whereas, among the 442 C3d-positive antibodies, SAB assays were positive except for 32 (7.2%) and 41 (9.3%) antibodies in the sections of MFI ≤500 and 1,001 ≤MFI ≤10,000, respectively. C3d-positive samples had higher maximum MFI values based on SAB assays, compared with C3d-negative samples. Conclusions MFI values of HLA class II antibodies detected through SAB assays in C3d-positive samples were higher than those in C3d-negative samples.

Background: We sought to compare the performance of three commercially available automated urine sediment analyzers that represent the current urine sediment analysis technology. Methods: A total of 232 patient samples were analyzed using manual microscopy and three automated analyzers: IRIS Iq200 (Beckman Coulter, USA), UF-1000i (Sysmex, Japan), and Cobas u701 (Roche, Switzerland). We analyzed precision, linearity, carry-over, concordance rate, and agreement between the three analyzers and manual microscopy. Results: The repeatability and within-laboratory precision showed results similar to those of previous studies. All analyzers showed excellent linearity. The carry-over rates were within 1%. The correlation coefficient (r) between the three analyzers and manual microscopy was good. Regarding red blood cell (RBC), the UF-1000i showed a better concordance rate (90.52%) with manual microscopy than the other two analyzers and the agreement was substantial for UF-1000i (κ=0.63) and IRIS Iq200 (κ=0.61). Regarding white blood cell (WBC), Cobas u701 showed the best concordance rate (96.55%) and the agreement was moderate for IRIS Iq200 (κ=0.57) and Cobas u701 (κ=0.56), and fair for UF-1000i (κ=0.47). Regarding epithelial cell (EPI), IRIS Iq200 showed the highest concordance rate (99.2%) and the agreement was moderate for IRIS Iq200 (κ=0.59) and Cobas u701 (κ=0.54), and fair for UF-1000i (κ=0.40). Conclusions IRIS Iq200 offered the best agreement with manual microscopy for WBC and EPI count, while UF-1000i showed a better agreement for RBC count. The agreement is insufficient for fully replacing the manual microscopy.