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Gregory A Storch

Publications and source records attributed to Gregory A Storch.

29 records · Page 2Linked to original sources

CMV infection of the renal allograft is much more common than the pathology indicates: a retrospective analysis of qualitative and quantitative buffy coat CMV-PCR, renal biopsy pathology and tissue CMV-PCR.

BACKGROUND: Quantitative blood polymerase chain reaction (PCR) for cytomegalovirus (CMV) is used to direct therapy in kidney transplant patients, but cytomegalic inclusions are rarely found in allograft renal biopsies even with an elevated serum creatinine and apparent CMV disease. The relationship between quantitative blood CMV and renal allograft pathology is unknown. METHODS: Thirteen biopsy samples were available for analysis from patients suspected of CMV disease, who had a buffy coat CMV-PCR drawn within 2-5 days of a renal allograft biopsy for an elevated creatinine. All were evaluated for CMV pathologically, by light microscopy, immunohistochemistry, in situ hybridization and tissue PCR. RESULTS: Qualitative and quantitative buffy coat CMV-PCR were positive in 10/13 (77%) patients. Tissue CMV-PCR was positive in five (50%) biopsies, including two with CMV inclusions and three with no inclusions. Quantitative buffy coat CMV-PCR levels did not correlate with detection of CMV inclusions in renal tissue. Paradoxically, quantitative buffy coat CMV-PCR was low (239 and 538 copies/microg of DNA) when CMV inclusions were detected. All five biopsies with acute rejection were associated with CMV viraemia and two of the five with allograft CMV inclusions. A quantitative buffy coat CMV-PCR of <100 copies/microg of DNA ruled out disease with CMV inclusions. CONCLUSIONS: CMV nephropathy is much more common than previously reported when sensitive techniques are used for detection in tissue. Acute rejection and CMV viraemia occur commonly together in patients at risk for CMV. Quantitative buffy coat CMV-PCR does not correlate with the presence of CMV inclusions. These findings have implications for management of patients who have elevated serum creatinine and are at risk for CMV disease.

Biopsy↗

Rapid diagnostic tests for influenza.

In recent years, seven rapid tests for influenza have become commercially available. These tests offer the promise of making rapid influenza diagnosis much more widely available than in the past, when rapid diagnosis could be made only by fluorescent antibody staining, a demanding technique available only in advanced laboratories. Two of the rapid tests have waived status under the Clinical Laboratory Improvements Amendments of 1988. This article describes each of the seven tests and reviews English-language publications that have evaluated the performance of these tests on specimens from children. A discussion of the implications of the tests for clinical decision-making is included.

Age Factors↗

Predominance of Ehrlichia ewingii in Missouri dogs.

To investigate the species distribution of Ehrlichia present in Missouri dogs, we tested 78 dogs suspected of having acute ehrlichiosis and 10 healthy dogs. Blood from each dog was screened with a broad-range 16S rRNA gene PCR assay that detects known pathogenic species of Ehrlichia and ANAPLASMA: The species was determined by using species-specific PCR assays and nucleotide sequencing. Ehrlichia antibody testing was performed by using an indirect immunofluorescence assay with Ehrlichia chaffeensis as the antigenic substrate. The broad-range assay detected Ehrlichia or Anaplasma DNA in 20 (26%) of the symptomatic dogs and 2 (20%) of the asymptomatic dogs. E. ewingii accounted for 20 (91%), and E. chaffeensis accounted for 1 (5%) of the positives. Anaplasma phagocytophilum DNA was detected in one dog, and the sequences of regions of the 16S rRNA gene and the groESL operon amplified from the blood of this dog matched the published sequences of this organism. Antibodies reactive with E. chaffeensis were detected in 14 (67%) of the 21 PCR-positive dogs and in 12 (19%) of the 64 PCR-negative dogs. Combining the results of PCR and serology indicated that 33 (39%) of 85 evaluable dogs had evidence of past or current Ehrlichia infection. We conclude that E. ewingii is the predominant etiologic agent of canine ehrlichiosis in the areas of Missouri included in this survey. E. canis, a widely recognized agent of canine ehrlichiosis, was not detected in any animal. The finding of E. ewingii in asymptomatic dogs suggests that dogs could be a reservoir for this Ehrlichia species.

Animals↗

Detection of Ehrlichia spp. in the blood of wild white-tailed deer in Missouri by PCR assay and serologic analysis.

Blood samples collected from wild deer in Missouri in November of 2000 and 2001 were positive by PCR assays for Ehrlichia chaffeensis (50 of 217; 23%), Ehrlichia ewingii (44 of 217; 20%), and Anaplasma species (214 of 217; 99%). Nucleotide sequences of selected amplicons from the assay for anaplasma matched sequences of the white-tailed deer agent. Serologic analysis of 112 deer sampled in 2000 showed a very high prevalence of antibodies to E. chaffeensis (97 of 112; 87%) and a low prevalence of antibodies reactive with Anaplasma phagocytophila (2 of 112; 2%).

Animal Diseases↗

Reinfection with Ehrlichia chaffeensis in a liver transplant recipient.

Human monocytic ehrlichiosis is an emerging infection caused by Ehrlichia chaffeensis, but reinfection with this agent has not been described. We report a case of reinfection with E. chaffeensis after a 2-year interval in a 56-year-old liver transplant recipient with frequent tick attachments.

Antibodies, Bacterial↗

Multiplex, quantitative, real-time PCR assay for cytomegalovirus and human DNA.

We created a multiplex, quantitative, real-time PCR assay that amplifies cytomegalovirus (CMV) and human DNA in the same reaction tube, allowing for a viral load determination that is normalized to measured human DNA. The assay targets a conserved region of the CMV DNA polymerase gene that is not affected by known drug resistance mutations. All 36 strains of CMV detected by culture or qualitative PCR in a population of lung transplant recipients were detected. The assay detected 1 to 10 copies of CMV plasmid DNA. The analytic sensitivity was not affected by the presence of DNA from 10(6) human cells but was reduced approximately 10-fold by alkaline lysates of leukocyte preparations. CMV quantitation was linear over a range of 10(1) to 10(6) copies. The intraassay and interassay coefficients of variation were 29 and 40%. Human DNA was regularly detected in patient plasma samples, and the amount was increased by storage of blood at room temperature before plasma separation and by plasma separation techniques that allowed leukocyte contamination. Applied to whole blood, the assay provides a measurement of CMV DNA in relation to cellular content without a need for cell counting procedures. Applied to plasma, the assay can reveal artifactual increases in plasma CMV levels resulting from leukocyte contamination. Further study of the utility of this assay to monitor patient populations at risk for CMV disease is warranted.

Adult↗

PCR for the diagnosis of toxoplasmosis after hematopoietic stem cell transplantation.

Toxoplasma gondii is a ubiquitous pathogen that causes significant morbidity and mortality in immunocompromised patients. Although relatively uncommon, toxoplasmosis is increasingly recognized as a severe complication of hematopoietic stem cell transplantation. Timely and accurate diagnosis of this treatable infection is critical. PCR-based testing has become the preferred method for diagnosis, occasionally replacing tissue biopsy. This article reviews the clinical, diagnostic and therapeutic aspects of toxoplasmosis in the setting of hematopoietic stem cell transplantation and the current and future role of PCR-based testing for early detection and diagnosis.

Animals↗

Detection of pathogenic Ehrlichia in ticks collected at acquisition sites of human ehrlichiosis in Missouri.

We collected 385 ticks from sites in Missouri associated with human monocytic ehrlichiosis. Using PCR, we detected E. chaffeensis or E. ewingii in 2 of 19 pools of adult Amblyomma americanum, 0 of 32 pools of Dermacentor variabilis, and 6 (18%) of 39 pools of unspeciated nymphal ticks from 3 of 6 sites associated with disease and one site not associated with disease. We also detected a variant of A. phagocytophila in one nymph pool.

Animals↗