Choi MS, et al. Ann Lab Med. 2018 Sep;38(5):466-472. https://doi.org/10.3343/alm.2018.38.5.466

Herpes simplex viruses types 1 and 2 (HSV-1 and HSV-2), and varicella-zoster virus (VZV) are common agents resulting in various forms of clinical manifestation from skin vesicle to disseminated viral infection. The aim of the present study was to develop a real-time PCR and melting curve analysis which detect and differentiate HSV-1, HSV-2, and VZV, to compare with PCR-RFLP using clinical specimens, and to introduce the 4-year experience in the clinical laboratory. Three pairs of primers for HSV-1, HSV-2, and VZV were designed. Primers for human endogenous retrovirus-3 (HERV-3), an internal control, were adopted. A hundred selected specimens and many clinical specimens were tested for methods comparison and assay validation. Increased sensitivity and specificity were obtained from real-time PCR. In review of results of clinical specimens submitted to clinical laboratory, a total of 46 of 3,513 specimens were positive in cerebrospinal fluids, blood, skin vesicles, genital swabs, aqueous humor, and ear discharge. Thus, this method could be a rapid and accurate alternative to virus culture and other molecular tests for detection and typing of HSV-1, HSV-2, and VZV.

Galactomannan (GM) is a polysaccharide cell wall component released by Aspergillus spp., and an immunoenzymatic GM assay is used for the diagnosis of invasive pulmonary aspergillosis. We evaluated the cause of strong positivity for GM in patients with no typical signs of aspergillosis. Repeat assays were performed using different instruments and reagent lots, but there were no differences in results among the assays. Patients with strongly positive GM results were investigated. Medication histories revealed that 14 of 23 patients had been administered total parenteral nutrition solution from one manufacturer and 4 patients had been administered dextrose solution from a different manufacturer before being tested. The results of GM assays conducted on samples of dextrose solution and the glucose fraction of the total parenteral nutrition solution were strongly positive, confirming the causes of the false-positive reactions. We hypothesize that a trace amount of GM was introduced into the glucose-containing solutions because glucoamylase, which is necessary for the saccharification step of glucose synthesis, was derived from Aspergillus niger. To enhance patient care and prevent unnecessary antifungal prescriptions, healthcare providers and manufacturers of healthcare products need to be aware of the possibility of false-positive reactions for GM.

Hong YJ, et al. Ann Lab Med. 2012 May;32(3):229-233. https://doi.org/10.3343/alm.2012.32.3.229

Serological weak D is a reaction of 2+ or less to anti-D reagent and includes weak D and partial D phenotypes. Although identifying the RhD subtype is important for transfusion safety, serological tests are insufficient for defining the RhD subtype, and molecular tests are needed. To analyze the molecular characteristics of D variants in Koreans to facilitate the formulation of individualized transfusion strategies, molecular tests such as RhD genotyping using real-time polymerase chain reaction (PCR) and partial-D and/or weak-D sequence-specific amplification (SSP) were performed on 105 Korean Rare Blood Program (KRBP) patients exhibiting serological weak D. In total, 58 out of 68 serologically determined weak D KRBP patients were typed as having weak D or partial D phenotypes via RhD genotyping. In detail, eight (13.8%) were typed as partial DVa or DBS, nine (15.5%) as weak D type 15, and four others (6.8%) as partial DVI, partial DVII, weak D type 2, or weak D type 41 or 45, whereas the rest (n = 37, 63.8%) was typed as having either weak D or partial D. This suggests that serological weak D Koreans who require transfusion should be treated as D-negative.