Blood culture bottles meet the operating room: enhancing the diagnostic accuracy of infectious spondylitis through open microsurgical biopsy and intraoperative inoculation.

PURPOSE: Infectious spondylitis is caused by hematogenous seeding or adjacent soft tissue infection. No study has provided evidence that incubating biopsy specimens in blood culture bottles could enhance detection rates, nor has any study compared this method with conventional culture techniques. We aimed to assess the diagnostic yield of open microsurgical biopsies for infectious spondylitis and the efficacy of various culture media in the presence and absence of pre-biopsy antibiotic therapy. METHODS: This retrospective study, which was conducted at a university-affiliated teaching hospital in Korea, enrolled 165 adult patients with suspected infectious spondylitis between February 2014 and September 2020. The diagnostic yield of open biopsy was compared among three culture media, namely, blood culture bottles, swab culture using transport media, and tissue culture using plain tubes, while considering preoperative antibiotic exposure. RESULTS: Causative bacteria were identified in 84.2% of all cases. Blood culture bottles had the highest positivity rate (83.5%), followed by swab cultures (64.4%) and tissue cultures (44.9%). The differences in positivity rates were significant (P < 0.001). Preoperative antibiotic therapy reduced detection rates across all media, particularly in tissue cultures. CONCLUSIONS: We established the high diagnostic yield of open microsurgical biopsy using blood culture bottles, suggesting that pre-biopsy antibiotic therapy significantly affects bacterial detection, thereby underscoring the importance of culture medium selection in the diagnosis of infectious spondylitis.

Performance evaluation of STANDARD Q COVID-19 Ag home test for the diagnosis of COVID-19 during early symptom onset.

BACKGROUND: Surveillance and control of SARS-CoV-2 outbreak through gold standard detection, that is, real-time polymerase chain reaction (RT-PCR), become a great obstacle, especially in overwhelming outbreaks. In this study, we aimed to analyze the performance of rapid antigen home test (RAHT) as an alternative detection method compared with RT-PCR. METHODS: In total, 79 COVID-19-positive and 217 COVID-19-negative patients confirmed by RT-PCR were enrolled in this study. A duration from symptom onset to COVID-19 confirmation of <5 days was considered a recruiting criterion for COVID-19-positive cases. A nasal cavity specimen was collected for the RAHT, and a nasopharyngeal swab specimen was collected for RT-PCR. RESULTS: Sensitivity of the STANDARD Q COVID-19 Ag Home Test (SD Biosensor, Korea), compared with RT-PCR, was 94.94% (75/79) (95% [confidence interval] CI, 87.54%-98.60%), and specificity was 100%. Sensitivity was significantly higher in symptomatic patients (98.00%) than in asymptomatic (89.66%) patients (p-value = 0.03). There was no difference in sensitivity according to the duration of symptom onset to confirmation (100% for 0-2 days and 96.97% for 3-5 days, respectively) (p-value = 1.00). The RAHT detected all 51 COVID-19 patients whose Ct values were ≤25 (100%), whereas sensitivity was 73.33% (11/15) among patients with Ct values >25 (p-value = 0.01). CONCLUSION: The RAHT showed an excellent sensitivity for COVID-19-confirmed cases, especially for those with symptoms. There was a decrease in sensitivity when the Ct value is over 25, indicating that RAHT screening may be useful during the early phase of symptom onset, when the viral numbers are higher and it is more transmissible.

Severe Fever with Thrombocytopenia Syndrome Patients with Hemophagocytic Lymphohistiocytosis Retrospectively Identified in Korea, 2008-2013.

The incidence of severe fever with thrombocytopenia syndrome (SFTS) has increased in Korea since a first report in 2013. We investigated whether SFTS existed before 2013 using real-time reverse transcription polymerase chain reaction and stored blood samples from febrile patients with thrombocytopenia. Four cases of SFTS were identified, with the earliest occurring in 2008.

Correlation of NPM1 Type A Mutation Burden With Clinical Status and Outcomes in Acute Myeloid Leukemia Patients With Mutated NPM1 Type A.

BACKGROUND: Nucleophosmin gene (NPM1) mutation may be a good molecular marker for assessing the clinical status and predicting the outcomes in AML patients. We evaluated the applicability of NPM1 type A mutation (NPM1-mutA) quantitation for this purpose. METHODS: Twenty-seven AML patients with normal karyotype but bearing the mutated NPM1 were enrolled in the study, and real-time quantitative PCR of NPM1-mutA was performed on 93 bone marrow (BM) samples (27 samples at diagnosis and 56 at follow-up). The NPM1-mutA allele burdens (represented as the NPM1-mutA/Abelson gene (ABL) ratio) at diagnosis and at follow-up were compared. RESULTS: The median NPM1-mutA/ABL ratio was 1.3287 at diagnosis and 0.092 at 28 days after chemotherapy, corresponding to a median log10 reduction of 1.7061. Significant correlations were observed between BM blast counts and NPM1-mutA quantitation results measured at diagnosis (γ=0.5885, P=0.0012) and after chemotherapy (γ=0.5106, P=0.0065). Total 16 patients achieved morphologic complete remission at 28 days after chemotherapy, and 14 (87.5%) patients showed a >3 log10 reduction of the NPM1-mutA/ABL ratio. The NPM1-mutA allele was detected in each of five patients who had relapsed, giving a median increase of 0.91-fold of the NPM1-mutA/ABL ratio at relapse over that at diagnosis. CONCLUSIONS: The NPM1-mutA quantitation results corresponded to BM assessment results with high stability at relapse, and could predict patient outcomes. Quantitation of the NPM1-mutA burden at follow-up would be useful in the management of AML patients harboring this gene mutation.

Bone marrow findings in severe fever with thrombocytopenia syndrome: prominent haemophagocytosis and its implication in haemophagocytic lymphohistiocytosis.

AIMS: Severe fever with thrombocytopenia syndrome (SFTS) is an emerging tick-borne disease caused by the SFTS virus; primary manifestations are fever, thrombocytopenia, leukopenia and gastrointestinal symptoms. Before an aetiological diagnosis is made, SFTS patients can undergo bone marrow examination due to cytopenias. Although several studies have reported on bone marrow examination in SFTS patients, most do not provide adequate details. Bone marrow findings in SFTS patients were investigated in this study. METHODS: An observational study was conducted in SFTS patients who were hospitalised between 2013 and 2014 in two university hospitals in South Korea. Patients were included in the study if SFTS was confirmed by real-time PCR for the SFTS virus and a bone marrow examination was conducted. The morphologic findings of the bone marrow samples were reviewed. RESULTS: Three cases met the study inclusion criteria. One patient died of multiple organ failure. Haemophagocytosis was evident in the bone marrow samples of all three patients. Histiocytic hyperplasia and haemophagocytosis were more pronounced in the fatal case. One patient was diagnosed as having haemophagocytic lymphohistiocytosis. CONCLUSIONS: Haemophagocytosis in the bone marrow of SFTS patients may be common. In SFTS endemic areas, SFTS should be one of the differential diagnoses of fever of unknown origin with haemophagocytosis in the bone marrow.

Incidence, clinical features, and prognostic impact of CALR exon 9 mutations in essential thrombocythemia and primary myelofibrosis: an experience of a single tertiary hospital in Korea.

We evaluated the incidence, clinical characteristics, and prognostic impact of calreticulin (CALR) mutations in essential thrombocythemia (ET) and primary myelofibrosis (PMF) patients. In all, 48 ET and 14 PMF patients were enrolled, and the presence of CALR mutations was analyzed by direct sequencing. Patients were classified into three subgroups according to Janus kinase 2 (JAK2) V617F and CALR mutation status, and their clinical features and prognosis were compared. CALR mutations were detected in 15 (24.2%) patients, and the incidence increased to 50.0% in 30 JAK2 V617F mutation-negative cases. These included 11 patients with three known mutations (c.1092_1143del [seven cases], c.1154_1155insTTGTC [three cases], and c.1102_1135del [one case]) and 4 patients with novel mutations. ET patients carrying CALR mutation were younger, had lower white blood cell counts, and experienced less thrombosis during follow-up than those carrying JAK2 V617F mutation, while both patient groups showed similar clinical features and prognosis. In ET patients without JAK2 V617F mutation, CALR mutation did not significantly affect clinical manifestation and prognosis. In conclusion, CALR mutation analysis could be a useful diagnostic tool for ET and PMF in 50% of the cases without JAK2 V617F mutations. The prognostic impact of CALR mutations needs further investigation.

Incidence and prognostic impact of DNMT3A mutations in Korean normal karyotype acute myeloid leukemia patients.

BACKGROUND: DNA methyltransferase 3A (DNMT3A) mutation was recently introduced as a prognostic indicator in normal karyotype (NK) AML and we evaluated the incidence and prognostic impact of DNMT3A mutations in Korean NK AML patients. METHODS: Total 67 NK AML patients diagnosed during the recent 10 years were enrolled. DNMT3A mutations were analyzed by direct sequencing and categorized into nonsynonymous variations (NSV), deleterious mutations (DM), and R882 mutation based on in silico analysis results. Clinical features and prognosis were compared with respect to DNMT3A mutation status. RESULTS: Three novel (I158M, K219V, and E177V) and two known (R736H and R882H) NSVs were identified and the latter three were predicted as DMs. DNMT3A NSVs, DMs, and R882 mutation were identified in 14.9%-17.9%, 10.3%-10.4%, and 7.5% of patients, respectively. DNMT3A mutations were frequently detected in FLT3 ITD mutated patients (P=0.054, 0.071, and 0.071 in NSV, DMs, and R882 mutation, resp.) but did not affect clinical features and prognosis significantly. CONCLUSIONS: Incidences of DNMT3A NSVs, DMs, and R882 mutation are 14.9%-17.9%, 10.3%-10.4%, and 7.5%, respectively, in Korean NK AML patients. DNMT3A mutations are associated with FLT3 ITD mutations but do not affect clinical outcome significantly in Korean NK AML patients.

Clinical relevance of high-resolution single nucleotide polymorphism array in patients with relapsed acute lymphoblastic leukemia with normal karyotype: a report of three cases.

We report three patients with normal karyotype (NK) ALL, who showed genetic aberrations as determined by high-resolution single nucleotide polymorphism array (SNP-A) analysis at both diagnosis and relapse. We evaluated the clinical relevance of the SNP-A assay for the detection of subtle changes in the size of affected genetic lesions at relapse as well as the prognostic value of the assay. In our patients, application of the SNP-A assay enabled sensitive detection of cryptic changes affecting clinically important genes in NK ALL. Therefore, this assay seems to be more advantageous compared to other conventional methods such as FISH assay, HemaVision (DNA Technology, Denmark), and conventional karyotyping for the detection of an "unstable genotype" at relapse, which may be associated with microscopic clonal evolution and poor prognosis. Further comprehensive studies are required to confirm the issues presented by our case patients in this report.

The first Korean case of Sphingobacterium spiritivorum bacteremia in a patient with acute myeloid leukemia.

Sphingobacterium spiritivorum has been rarely isolated from clinical specimens of immunocompromised patients, and there have been no case reports of S. spiritivorum infection in Korea to our knowledge. We report a case of S. spiritivorum bacteremia in a 68-yr-old woman, who was diagnosed with acute myeloid leukemia and subsequently received chemotherapy. One day after chemotherapy ended, her body temperature increased to 38.3℃. A gram-negative bacillus was isolated in aerobic blood cultures and identified as S. spiritivorum by an automated biochemical system. A 16S rRNA sequencing analysis confirmed that the isolate was S. spiritivorum. The patient received antibiotic therapy for 11 days but died of septic shock. This is the first reported case of human S. spiritivorum infection in Korea. Although human infection is rare, S. spiritivorum can be a fatal opportunistic pathogen in immunocompromised patients.

A case of Streptococcus gallolyticus subsp. gallolyticus infective endocarditis with colon cancer: identification by 16S ribosomal DNA sequencing.

Although the association between Streptococcus bovis endocarditis and colon carcinoma is well known, very few cases of S. bovis infection associated with underlying malignancies have been reported in Korea. The S. bovis group has been recently reclassified and renamed as Streptococcus gallolyticus and Streptococcus infantarius subspecies under a new nomenclature system. We report a case of infective endocarditis with colon cancer caused by S. gallolyticus subsp. gallolyticus (previously named S. bovis biotype I). A 59-yr-old woman presented with a 1-month history of fever. Initial blood cultures were positive for gram-positive cocci, and echocardiography showed vegetation on mitral and aortic valves. Antibiotic treatment for infective endocarditis was started. The infecting strain was a catalase-negative and bile-esculin-positive alpha-hemolytic Streptococcus susceptible to penicillin and vancomycin. The strain was identified as S. gallolyticus subsp. gallolyticus with the use of the Vitek 2 GPI and API 20 Strep systems (bioMérieux, USA). The 16S rDNA sequences of the blood culture isolates showed 100% homology with those of S. gallolyticus subsp. gallolyticus reported in GenBank. The identification of the infecting organism, and the subsequent communication among clinical microbiologists and physicians about the changed nomenclature, led to the detection of colon cancer. The patient recovered after treatment with antibiotics, valve surgery, and operation for colon cancer. This is the first report of biochemical and genetic identification of S. gallolyticus subsp. gallolyticus causing infective endocarditis associated with underlying colon cancer in a Korean patient.

Risk factors for poor treatment outcome and central nervous system relapse in diffuse large B-cell lymphoma with bone marrow involvement.

Although several studies have described the prognostic implication of bone marrow (BM) involvement (BMI) in lymphoma, studies focused on BM-involved diffuse large B-cell lymphoma (DLBCL) are very rare and small-sized. This study was performed to examine the prognostic impact of morphologic findings of BMI by lymphoma and risk factors for central nervous system (CNS) relapse in BM-involved DLBCL. Between 1993 and 2005, 675 patients were diagnosed with DLBCL, and 88 patients who had BMI at initial diagnosis were eligible for this study. The median overall survival (OS) and failure-free survival (FFS) of 88 patients were 36.6 and 20.1 months, respectively. When three variables from BM morphologic findings (the pattern of BM infiltration, extent of BMI by lymphoma, and percentage of large cells in the infiltrate) were simultaneously included into multivariate model, the increased extent of BMI by lymphoma (> or =10%) in BM area was the only negative prognostic factor, independent of the International Prognostic Index (IPI). Patients with both lower IPI scores and less extent of BMI showed an excellent prognosis with chemotherapy alone (5-year OS and FFS rates, 80% and 69%). However, morphologic BM features were not independent predictive factors for CNS recurrences. An increased lactate dehydrogenase (LDH) level at initial diagnosis was the only independent predictive factor for CNS relapse. Further efforts should be directed toward finding optimal treatment modalities based on the IPI and the extent of BMI by lymphoma. CNS prophylaxis may be considered only in patients with initial elevated LDH levels.

[Production and characterization of anti-staphylococcal toxic shock syndrome toxin-1 monoclonal antibody].

BACKGROUND: Recently the association between the virulence factors of Staphylococcus aureus and the outcome of the patients infected with the organism appears to be the subject of active investigation. Toxic shock syndrome toxin-1 (TSST-1) is thought to be a clinically more significant virulence factor than other staphylococcal toxins. We attempted to produce and characterize monoclonal antibodies to staphylococcal TSST-1. METHODS: An important epitope of TSST-1, amino acids 1-15 region, was synthesized into a peptide antigen, and Balb/c mice were immunized by intraperitoneal injection of the synthetic antigen. Hybridomas were produced by fusing immunized murine splenocytes with immortal myeloma cells. Hybridomas were cloned through a limiting dilution method. Stable cultured hybridoma was injected into the peritoneal cavity of Balb/c mice, and peritoneal fluid containing the monoclonal antibody was produced. RESULTS: One IgG(2b) type monoclonal antibody and two IgM type monoclonal antibodies were obtained. The IgG(2b) type monoclonal antibody was able to detect 5 microg of TSST-1 with Western blot analysis and showed a strong reactivity to TSST-1 with ELISA. CONCLUSIONS: Highly immunoreactive anti-TSST-1 monoclonal antibody was produced by the use of synthesized peptide antigen. Diagnostic and protective capacity of this monoclonal antibody should be evaluated in the future.

Extramedullary relapse confirmed by fluorescence in situ hybridization study of an ear mass in acute promyelocytic leukemia.

A 40-year-old man with acute promyelocytic leukemia (APL) achieved complete remission after induction chemotherapy combined with all-trans-retinoic acid. A mass developed in the left ear 24 months later. Relapse of APL was suspected at morphologic examination of the biopsy specimen of the ear mass, but t(15;17) and PML/RAR alpha rearrangement were not detected by chromosomal, fluorescence in situ hybridization (FISH), or reverse transcription polymerase chain reaction analysis of bone marrow samples. FISH performed on the ear mass revealed t(15;17). To our knowledge, this case is the first reported case of extramedullary relapse of APL confirmed by FISH study of a biopsy specimen of extramedullary tissue.