Archives of pathology & laboratory medicine
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Arch. Pathol. Lab. Med. · Dec 1994
Diagnosis of histoplasmosis by antigen detection during an outbreak in Indianapolis, Ind.
In this study we examine the sensitivity of Histoplasma capsulatum var capsulatum antigen detection for the diagnosis of histoplasmosis. This was a retrospective review of the sensitivity of antigen detection in patients who were diagnosed as having self-limited, chronic pulmonary, or disseminated histoplasmosis during an outbreak in Indianapolis, Ind. All patients had clinical and laboratory evidence of histoplasmosis, and specimens of urine or serum that were obtained from the patients were tested for H capsulatum var capsulatum antigen. ⋯ Antigen was detected in 92%, 21%, and 39% of the patients with the disseminated, chronic pulmonary, and self-limited forms of histoplasmosis, respectively. Tests for the antigen are most useful in patients with clinical findings of disseminated infection. Antigen detection also may be useful in those patients with more severe pulmonary involvement, especially during the first month of illness when serologic tests for antibodies may be negative.
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Arch. Pathol. Lab. Med. · Dec 1994
Case Reports Comparative StudyTransfusion-associated human immunodeficiency virus type 1 from screened antibody-negative blood donors.
Cases of human immunodeficiency virus type 1 (HIV-1) infection acquired from transfusion of screened antibody-negative blood have been reported since 1986. Recent reports have proposed new combination antibody assays or the addition of HIV-1 p24 antigen testing to enhance the screening of blood donations further. Since antibody testing for HIV-1 began in 1985, 700,000 donor units have been screened at US Army blood donor centers. ⋯ The status of blood donors who are in the early stages of HIV-1 infection may not be detected by current screening methods. While this is a rare phenomenon, it highlights the need for technologic developments in screening methods to narrow the time between infection and detection. In addition, it emphasizes the need for more effective education and counseling to enhance the utility of self=deferral.
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Arch. Pathol. Lab. Med. · Apr 1994
ReviewEffects of transfusion on immune function. Cancer recurrence and infection.
The paradigm related to the immunologic consequences of allogeneic blood transfusions has been extended from humoral allosensitization to the effects of transfusion on cellular immune function. This includes downregulation of effector cells, activation of latent viral infection, and the prolonged circulation of donor immunocompetent cells, as seen in graft-vs-host disease. There are now extensive data showing conclusively that allogeneic transfusions are associated with increases in cancer recurrence rates (80% in colorectal cancer) and postoperative bacterial infections (as much as 200% to 1000% in some studies). ⋯ This favors presentation of antigen by "nonprofessional" antigen-presenting cells, a situation that usually leads to anergy or tolerance rather than immune activation. Two additional hypothetical mechanisms proposed for immune dysregulation after allogeneic transfusion are (1) prolonged circulation of donor cells causing subclinical graft-vs-host disease, and (2) reactivation of immunosuppressive viruses latently present in recipient white blood cells. Results of some initial interventional studies, employing autologous transfusions or removing white blood cells from allogenic donor blood suggest that relatively simple, cost-effective strategies to ameliorate these complications may be at hand.
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Arch. Pathol. Lab. Med. · Feb 1994
An investigation of the viral pathogenesis of Kikuchi-Fujimoto disease. Lack of evidence for Epstein-Barr virus or human herpesvirus type 6 as the causative agents.
Histiocytic necrotizing lymphadenitis of Kikuchi and Fujimoto is a well-defined clinicopathologic entity of unknown cause. Both the Epstein-Barr virus (EBV) and human herpesvirus type 6 (HHV-6) have been suggested as potential etiologic agents. Twenty cases of Kikuchi-Fujimoto disease were studied for the presence of EBV DNA and HHV-6 DNA by the polymerase chain reaction (PCR), and in situ hybridization in the case of EBV. ⋯ These results indicate that inconsistent results by PCR may occur with very low levels of viral genomes and that different laboratories perform DNA amplification at different efficiencies. Alternatively, laboratory contamination may give rise to false-positive results. Therefore, a positive result for EBV should be interpreted with caution and should be confirmed by repeated study (PCR) or by independent methodology (in situ hybridization).
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Arch. Pathol. Lab. Med. · Jul 1993
Performance characteristics of the HemoCue B-Glucose analyzer using whole-blood samples.
We evaluated the HemoCue B-Glucose (HemoCue Inc, Mission Viejo, Calif) analyzer for accuracy, precision, linearity, and recovery. One hundred eighteen capillary whole-blood samples were analyzed in duplicate on the HemoCue B-Glucose and the YSI 2300 STAT Glucose/L-Lactate (Yellow Springs [Ohio] Instruments) analyzers; corresponding plasma glucose levels were measured in duplicate on the Roche Cobas MIRA (Roche Diagnostic Systems, Nutley, NJ) analyzer. Plasma glucose levels were converted to whole-blood equivalent glucose levels by using a factor of 1.11. ⋯ Between-run imprecision and total imprecision using lyopholized materials with three lot numbers of cuvettes were 4.2% and 5.6% at 2.1 mmol/L (37 mg/dL) and 2.4% and 2.7% at 5.2 mmol/L (95 mg/dL), respectively. The HemoCue B-Glucose analyzer displayed linearity between 0 and 22.2 mmol/L (0 and 400 mg/dL), and the percent recovery averaged 98.7% +/- 4.5% (mean +/- SD). The HemoCue B-Glucose analyzer is a rapid, simple, and reliable method for determinations of whole-blood glucose levels.