ABSTRACT
BK virus (BKV) is associated with kidney and bladder disease after hematopoietic cell transplantation (HCT) but less is known about the seroprevalence of pre-transplant antibodies to BKV in children. We measured BKV IgG antibody titers in 36 children before HCT. BKV IgG antibodies were detected in all 36 patients, with 28/36 (77.8%) developing BK viremia in the first 100 days. Pre-HCT BKV IgG antibody titers >1:40,960 were protective against later BK viremia ≥10,000 copies/ml. The seroprevalence of antibodies to BKV is high in children undergoing HCT and post-transplant BK viremia, which is associated with bladder and kidney injury, is common.
Subject(s)
Antibodies, Viral/blood , BK Virus/immunology , Hematopoietic Stem Cell Transplantation , Polyomavirus Infections/immunology , Tumor Virus Infections/immunology , Virus Activation , Adolescent , BK Virus/isolation & purification , BK Virus/physiology , Child , Cystitis/etiology , Cystitis/virology , Disease Susceptibility , Female , Hematopoietic Stem Cell Transplantation/adverse effects , Hematuria/etiology , Hematuria/virology , Humans , Male , Polyomavirus Infections/blood , Polyomavirus Infections/epidemiology , Risk , Seroepidemiologic Studies , Transplantation Conditioning/adverse effects , Tumor Virus Infections/blood , Tumor Virus Infections/epidemiology , Viral Load , Viremia/epidemiology , Viremia/etiologyABSTRACT
Hematopoietic stem cell transplant (HSCT) recipients are at significant risk for BK virus (BKV) reactivation, hemorrhagic cystitis (HC), and renal dysfunction. We prospectively monitored 98 patients who had received HSCT by serial BKV PCR in the urine through day (D) +100 to analyze the relationship between BK viruria and HC, serum creatinine (Cr), and creatinine clearance (CrCl) through D +180 or death. Patients, median age 52 years (range, 20 to 73), received T cell-depleted (50%) or cord blood allografts (21%). Median pre-HSCT BKV IgG titers were 1:10,240. Incremental increase in BKV IgG titers correlated with developing BK viruria ≥ 10(7) copies/mL. By D +100, 53 (54%) patients had BK viruria. BKV load in the urine increased at engraftment and persisted throughout D +100. HC developed in 10 patients (10%); 7 of 10 with BK viruria. In competing risk analyses, BK viruria ≥ 10(7) copies/mL, older age, cytomegalovirus reactivation, and foscarnet use were risk factors for HC. Cr and CrCl at 2, 3, and 6 months after HSCT were similar between patients with and without BK viruria.
Subject(s)
BK Virus/pathogenicity , Cord Blood Stem Cell Transplantation/adverse effects , Cystitis/etiology , Adult , Aged , BK Virus/growth & development , Cohort Studies , Cystitis/urine , Female , Humans , Male , Middle Aged , Risk Factors , T-Lymphocytes/virology , Young AdultABSTRACT
This is the first report of blue autofluorescence as a useful characteristic in the microscopic detection of Toxoplasma gondii, Hammondia hammondi, Hammondia heydorni, Neospora caninum, Besnoitia darlingi, and Sarcocystis neurona oocysts or sporocysts. This autofluorescence is of sufficient intensity and duration to allow identification of these oocysts from complex microscopic sample backgrounds. As with the autofluorescence of related coccidia, the oocysts glow pale blue when illuminated with an ultraviolet (UV) light source and viewed with the correct UV excitation and emission filter set.
Subject(s)
Coccidia/isolation & purification , Fluorescence , Toxoplasma/isolation & purification , Animals , Cats , Coccidia/physiology , Dogs , Feces/parasitology , Humans , Microscopy, Fluorescence , Neospora/isolation & purification , Neospora/physiology , Oocysts/isolation & purification , Oocysts/physiology , Opossums , Sarcocystidae/isolation & purification , Sarcocystidae/physiology , Sarcocystis/isolation & purification , Sarcocystis/physiology , Toxoplasma/physiologyABSTRACT
Cyclospora cayetanensis, a coccidian parasite, with a fecal-oral life cycle, has become recognized worldwide as an emerging human pathogen. Clinical manifestations include prolonged gastroenteritis. While most cases of infection with C. cayetanensis in the United States have been associated with foodborne transmission, waterborne transmission has also been implicated. We report on the development and application of a real-time, quantitative polymerase chain reaction assay for the detection of C. cayetanensis oocysts, which is the first reported use of this technique for this organism. Both a species-specific primer set and dual fluorescent-labeled C. cayetanensis hybridization probe were designed using the inherent genetic uniqueness of the 18S ribosomal gene sequence of C. cayetanensis. The real-time polymerase chain reaction assay has been optimized to specifically detect the DNA from as few as 1 oocyst of C. cayetanensis per 5 microl reaction volume.
Subject(s)
Cyclospora/isolation & purification , Polymerase Chain Reaction/methods , Animals , Cyclospora/genetics , Cyclospora/growth & development , Cyclosporiasis/diagnosis , Feces/parasitology , Flow Cytometry/methods , Humans , Oocysts/isolation & purification , Parasitic Sensitivity TestsABSTRACT
Nitroxide-labeled nucleic acids are used as a molecular size sensor to identify as few as one genome under polymerase chain reaction (PCR) conditions by electron paramagnetic resonance (EPR) spectroscopy. DNA identification is based on differences in the EPR spectra of mononitroxide-labeled nucleic acids. The experimental data imply that rapid DNA identification can be achieved in many systems by EPR at the molecular level.
