So Young Kang

Utility of Procalcitonin as an Early Diagnostic Marker of Bacteremia in Patients with Acute Fever

Purpose Procalcitonin (PCT) is a current, frequently used marker for severe bacterial infection. The aim of this study was to assess the ability of PCT levels to differentiate bacteremic from nonbacteremic patients with fever. We assessed whether PCT level could be used to accurately rule out a diagnosis of bacteremia. Materials and Methods Serum samples and blood culture were obtained from patients with fever between August 2008 and April 2009. PCT was analyzed using a VIDAS® B.R.A.H.M.S PCT assay. We reviewed the final diagnosis and patient histories, including clinical presentation and antibiotic treatment. Results A total of 300 patients with fevers were enrolled in this study: 58 with bacteremia (positive blood culture) (group I); 137 with local infection (group II); 90 with other diseases (group III); and 15 with fevers of unknown origin (group IV). PCT levels were significantly higher in patients with bacteremia than in those with non-bacteremia (11.9 ± 25.1 and 2.5 ± 14.7 ng/mL, respectively, p < 0.001). The sensitivity and specificity were 74.2% and 70.1%, respectively, at a cut-off value of 0.5 ng/mL. A serum PCT level of < 0.4 ng/mL accurately rules out diagnosis of bacteremia. Conclusion In febrile patients, elevated PCT may help predict bacteremia; furthermore, low PCT levels were helpful for ruling out bacteremia as a diagnosis. Therefore, PCT assessment could help physicians limit the number of prescriptions for antibiotics.

FISH-negative cryptic PML–RARA rearrangement detected by long-distance polymerase chain reaction and sequencing analyses: a case study and review of the literature

Although a normal karyotype according to conventional cytogenetic analysis in association with cryptic t(15;17) has been infrequently reported in cases of acute promyelocytic leukemia (APL), a fluorescence in situ hybridization (FISH)-negative cryptic PML-RARA rearrangement is even more rare, with only 12 such APL cases of FISH-negative cryptic PML-RARA rearrangements in the literature. Reported here is an additional clinical APL case with a FISH-negative cryptic PML-RARA rearrangement, confirmed by long-distance DNA polymerase chain reaction method. Discussion includes a relevant literature review of similar cases. DNA-PCR can be a useful tool for the analysis of complex and cryptic rearrangements.

Clinical usefulness of free light chain concentration as a tumor marker in multiple myeloma.

Monoclonal immunoglobulin, as a marker for monoclonal gammopathy, is evaluated by protein electrophoresis (PEP) and immunofixation electrophoresis (IFE). However, PEP and IFE are not satisfactory in sensitivity, objectivity, and facility. Recently, a highly sensitive, automated immunoassay for measurement of free light chain (FLC) concentrations in serum and urine has been developed for the identification and monitoring of patients with monoclonal gammopathy. To explore the clinical usefulness of measurement of FLC concentrations, we measured the κ and λ FLC concentrations and calculated the κ/λ FLC ratios for three groups [multiple myeloma (MM), other diseases, and control] and compared the results of the FLC assay with the results of PEP or IFE. The concentrations of serum κ and λ FLCs and the κ/λ FLC ratios for the MM group and non-MM groups were distinct. In the MM group, some sera and urine samples had no evidence of M protein on PEP and IFE, but FLC assay showed abnormal concentrations of FLCs and abnormal κ/λ FLC ratios in most cases. As compared with the PEP, the κ/λ FLC ratio revealed higher sensitivity in all diagnostic ranges with different cutoff values. Particularly, when the cutoff value 2.0 for κ/λ FLC ratio was used, specificity and positive predictive value were largely improved than when the cutoff values 1.2 and 1.5 were used. These findings indicated that FLC assay enables to detect myeloma patients with very low M protein due to early stage or after therapy and to distinguish patients with monoclonal increase of FLC from patients with polyclonal increase of FLC due to other conditions, particularly using κ/λ FLC ratio 0.3–2.0 as a diagnostic range. Despite some technical limitations of the assay, the incorporation of κ/λ FLC ratios with FLC concentrations is useful in the detection of M protein, particularly with negative serum or urine IFE results, and differentiation of monoclonal gammopathies from patients with polyclonal increase in FLC due to other conditions.

The prevalence of "anti-HBc alone" and HBV DNA detection among anti-HBc alone in Korea.

The “anti‐HBc alone” is a frequent serological finding in clinical laboratories, making it difficult to determine whether the HBV infection has resolved. The objectives of this study were to investigate the prevalence of anti‐HBc alone and HBV DNA detection (occult HBV infection) among anti‐HBc alone, and to describe the demographic and clinical characteristics of anti‐HBc alone. A total of 17,677 sera referred from the Health Promotion Center (HPC group, 4,014 sera) as well as all the hospital clinical departments (Patient group, 13,663 sera) were tested for HBs Ag, anti‐HBc, and anti‐HBs. HBV DNA test using real‐time PCR was performed on 230 anti‐HBc alone. The prevalence of anti‐HBc alone was 8.9%, significantly higher in the Patient group than in the HPC group. The prevalence of anti‐HBc was higher in men than women and was increased with age. Very low levels of HBV DNA were found in only 4 (1.7%) out of 230 subjects with anti‐HBc alone. They were patients with conditions unrelated to chronic liver disease. Considering the high prevalence of anti‐HBc alone, the frequency of occult HBV infection among anti‐HBc alone was unexpectedly low. In addition, HBV viral load was low in these patients. Further studies are required to determine the clinical significance and infectivity of anti‐HBc alone, in conjunction with very low levels of HBV DNA and to standardize the detection methodology for both anti‐HBc alone and HBV DNA. J. Med. Virol. 82:1508–1514, 2010.

[HLA-B27 subtypes in Korean patients with ankylosing spondylitis].

BACKGROUND HLA-B27 is strongly associated with ankylosing spondylitis (AS), and its subtypes differ in their ethnic distribution. Studies worldwide have shown that B*2701, B*2702, B*2704, B*2705, B*2707, B*2708, B*2714, B*2715, and B*2719 are AS-predisposing subtypes, whereas B*2706 and B*2709 are reported to be negatively associated with AS. The aim of this study was to investigate HLA-B27 polymorphism and clinical features according to subtypes in Korean patients with AS. METHODS Two hundred thirty samples from patients with impression of AS were analyzed by polymerase chain reaction using a sequence-specific primers (PCR-SSP) method. Pel-Freez SSP Unitray HLA-B*27 kit (Dynal Biotech, USA) including 16 primers was used to define HLA-B27 subtypes from B*2701 to B*2735. RESULTS Among 230 samples from patients with impression of AS, 171 were HLA-B27 positive, and among 160 patients diagnosed as AS, 154 (96.3%) were HLA-B27 positive, while 17 patients not diagnosed as AS were HLA-B27 positive. Among 154 HLA-B27 positive patients with AS, 142 (92.2%) were typed as B*2705 and 9 (5.8%) were typed as B*2704. Three cases (1.9%) could be interpreted only variously because of their HLA-B27 homogeneous alleles. Between B*2705 and B*2704, no specific HLA-B27 subtype appeared to contribute to AS susceptibility (P=0.60). Difference in clinical features between B*2705 and B*2704 could not be found in this study (P>0.05). CONCLUSIONS This study verified that HLA-B27 (96.3%) is strongly associated with AS and identified that the major subtypes of HLA-B27 positive patients with AS in Korea are B*2705 (92.2%) and B*2704 (5.8%).

Detection of Methicillin-Resistant Staphylococcus aureus in Healthcare Workers Using Real-Time Polymerase Chain Reaction

Healthcare-associated infections caused by methicillin-resistant Staphylococcus aureus (MRSA) have recently become an important issue for healthcare facilities due to high rates of infection, mortality, and high treatment costs. We investigated the frequency of MRSA in healthcare workers (HCWs) via nasal carriage and assessed the performance of the LightCycler® MRSA Advanced test. We tested nasal swabs from the anterior nares of participating HCWs at an intensive care unit. Nasal swabs were identified as S. aureus, methicillin-sensitive or methicillin-resistant coagulase-negative staphylococci (MSCoNS or MRCoNS), or MRSA by using conventional culture and the LightCycler® MRSA Advanced test. Of the 142 HCWs who participated in this study, only 11 participants (7.8%) were MRSA-positive by conventional culture and MRSA ID, and 24 (16.9%) were positive for mecA by real time polymerase chain reaction (PCR). In terms of diagnostic performance, the LightCycler® MRSA Advanced test had a sensitivity of 100%, a specificity of 90.1%, a positive predictive value of 45.8%, and a negative predictive value of 100% compared with conventional culture method. The detection limit of the LightCycler® MRSA Advanced test was 103 colony/mL. We concluded that real-time PCR was able to rapidly and sensitively detect MRSA in HCWs. However, MRSA must be confirmed by culture due to false positivity.

Evaluation of a new rapid test kit to detect hepatitis C virus infection

This study investigated the performance characteristics and diagnostic usefulness of a new rapid device test (RDT) for HCV (SD Bioline, Korea). A total of 200 specimens were used in this study and to assess cross-reactivity, five hepatitis B surface antigen (HBsAg) positive, five anti-hepatitis B surface antibody (anti-HBs) positive, five rheumatoid factor (RF) positive, and six samples from multiple myeloma patients were tested. The early detection capability of the test was assessed using seroconversion panels. Sensitivity and specificity were calculated compared with a recombinant immunoblot assay (RIBA). Sixty-six cases were positive by the RIBA, while 52 cases were positive using the new RDT. The sensitivity and specificity of the new RDT were 78.8% (95% CI: 71.2-86.8%) and 100%, respectively. The kappa value for the agreement between the new RDT and RIBA results was 0.831 (95% CI: 0.746-0.916). The early detection capability of the new RDT and a HCV EIA were similar, with the same window period. The new RDT did not cross-react with HBsAg, anti-HBs, RF and immunoglobulins. In conclusion, the SD Bioline HCV RDT has superior sensitivity and specificity than the GENEDIA® HCV Rapid LF that is used in Korea. This assay can be used for HCV screening, especially in small hospitals, without the financial burden of expensive equipment.

Measurement of Inflammatory Cytokines in Patients with Rheumatoid Arthritis

BACKGROUND Inflammatory cytokines such as tumor necrosis factor alpha (TNFalpha) and interleukin (IL)-6 play an important role in pathophysiology of rheumatoid arthritis (RA). We investigated the possibility whether TNFalpha and IL-6 could be used as an objective marker reflecting treatment response in RA. METHODS Erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and rheumatoid factor (RF) together with TNFalpha and IL-6 were measured in 159 specimens obtained from 95 RA patients. RA patients were divided into pre-treatment, methotrexate (MTX) and non-MTX groups by treatment regimen and into inactive and active groups by disease activity. The agreement between changes in marker levels and treatment response, and the correlation between each marker were analyzed. RESULTS IL-6 was higher in active than in inactive group of patients in all three different treatment subgroups, but TNFalpha was not different between the two groups. IL-6 showed a better agreement with treatment response (MTX group, K=0.58; non-MTX group, K=0.21) than ESR or CRP, whereas TNFalpha did not show an agreement with treatment response. IL-6 was correlated with both ESR (r=0.22) and CRP (r=0.54), but TNFalpha was correlated only with ESR (r=0.21). CONCLUSIONS Unlike TNFalpha, IL-6 reflects disease activity of RA and shows a better agreement with treatment response than ESR or CRP, indicating that it has an association with clinical features of RA. Therefore IL-6 could be used as an additional marker in the evaluation of treatment response when markers like ESR or CRP show results discordant from clinical features.

Prevalence and Antibiotic Susceptibility of Mycoplasma hominis and Ureaplasma urealyticum in Pregnant Women

Mycoplasma hominis (M. hominis) and Ureaplasma urealyticum (U. urealyticum) are important opportunistic pathogens that cause urogenital infections and complicate pregnancy. The aim of this study was to investigate the prevalence, effects on pregnancy outcomes, and antimicrobial susceptibilities of M. hominis and U. urealyticum. We tested vaginal swabs obtained from 1035 pregnant women for the presence of genital mycoplasmas between June 2009 and May 2014. The laboratory and clinical aspects of genital mycoplasmas infection were reviewed retrospectively, and the identification and antimicrobial susceptibility of genital mycoplasmas were determined using the Mycoplasma IST-2 kit. A total of 571 instances of M. hominis and/or U. urealyticum were detected. Of them, M. hominis was detected in two specimens, whereas U. urealyticum was detected in 472 specimens. The remaining 97 specimens were positive for both M. hominis and U. urealyticum. Preterm deliveries were frequently observed in cases of mixed infection of M. hominis and U. urealyticum, and instances of preterm premature rupture of membrane were often found in cases of U. urealyticum. The rates of non-susceptible isolates to erythromycin, empirical agents for pregnant women, showed increasing trends. In conclusion, the prevalence of M. hominis and/or U. urealyticum infections in pregnant women is high, and the resistance rate of antimicrobial agents tends to increase. Therefore, to maintain a safe pregnancy, it is important to identify the isolates and use appropriate empirical antibiotics immediately.

Crystalloid podocytopathy with focal segmental glomerulosclerosis in PCM: a case report

BackgroundCrystalloid podocytopathy with focal segmental glomerulosclerosis in plasma cell myeloma (PCM) is rare.Case PresentationWe present a case of crystalline deposition in the bone marrow (BM) and various renal cells with only proteinuria as a symptom. As workup for proteinuria, a renal biopsy sample was obtained. EM showed multiple crystalline depositions in renal tubular cells and podocytes. Focal segmental glomerulosclerosis with crystalloid podocytopathy was diagnosed. Because monoclonal gammopathy was detected in the serum and urine, a BM study was also performed. Plasma cells with needle-shaped inclusion bodies were observed. The crystalline deposits in the plasma cells and podocytes were positive for Masson’s trichrome and kappa light-chain staining. These findings indicated that the crystalline deposits originated from paraprotein. The case showed a rare process of focal segmental glomerulosclerosis via crystalline deposition in podocytes in plasma cell myeloma.ConclusionsCrystalloid podocytopathy is a likely cause of renal damage such as FSGS in PCM, although it is an uncommon mechanism for myeloma kidney.