[AIDS-related primary CNS non-Hodgkin's lymphoma in a patient with previous Epstein-Barr virus panuveitis. A clinico-pathological report]. / Linfoma no-Hodgkin primario del sistema nervioso central asociado a sida en un paciente con panuveítis por virus Epstein-Barr. Reporte clínico-patológico.

CLINICAL CASE: Patient with AIDS and Epstein-Barr virus (EBV) uveitis. The PCR of the aqueous and vitreous humor was positive for EBV, and DNA quantification was 56.602×10(6) copies/ml in the vitreous humor, 173,400 copies/ml in the peripheral blood, and negative in the cerebrospinal fluid (CSF). The patient developed a non-Hodgkin's lymphoma (NHL), diagnosed in the autopsy. CONCLUSION: The EBV is a rare cause of uveitis and it may be necessary to perform a quantitative PCR to reach the diagnosis. High amounts of EBV DNA are associated with a greater incidence of NHL.

Rapid detection of pneumococcal antigen in serum samples for diagnosing pneumococcal pneumonia.

OBJECTIVES: The aim of the study is to assess the usefulness of C polysaccharide and polysaccharide capsular antigen detection by immunochromatography (ICT) and enzyme immunoassay (EIA), respectively, in serum samples for diagnosing pneumococcal pneumonia. METHODS: Adult patients included in the study were classified in the following groups: In group 1 we studied 101 serum samples from patients with pneumonia due to Streptococcus pneumoniae. In 53 cases the pneumonia was bacteremic. The second group contained 113 serum samples from patients with no pneumococcal pneumonia. Group 3 was made up of 40 serum samples from healthy subjects with no clinical or radiological signs of pneumonia. RESULTS: Using ICT, antigen was detected in 50% of patients with pneumococcal pneumonia, in 64.3 and 40.9% of patients with bacteremic and non-bacteremic pneumococcal pneumonia, respectively. Using EIA, antigens were detected in 35.8% of patients with pneumococcal pneumonia, in 45 and 22.2% of patients with bacteremic and non-bacteremic pneumococcal pneumonia, respectively. CONCLUSIONS: In conclusion, the sensitivity of the tests is low. However, in special situations, where obtaining large volume of urine is difficult, they could be a complementary method in the rapid diagnosis of pneumococcal pneumonia.

Clinical usefulness of total hepatitis C virus core antigen quantification to monitor the response to treatment with peginterferon alpha-2a plus ribavirin*.

SUMMARY: Early virological response may predict outcome following treatment with peginterferon alpha-2a and ribavirin in patients chronically infected with hepatitis C virus (HCV). As total HCV core antigen may constitute an alternative direct marker to HCV RNA for assessing the levels of viraemia in such patients, we evaluated the correlation between HCV core antigen and HCV RNA, and whether HCV core antigen at baseline, 4 and 12 weeks after treatment could predict sustained virological response (SVR) to combined therapy, in comparison with HCV RNA. A total of 290 serum samples from 58 previously treatment naïve chronic HCV patients were examined for HCV core antigen and HCV-RNA by means of quantitative HCV RNA when receiving combination therapy for the first time. SVR was significantly associated with basal HCV core antigen but not with HCV RNA. There was a good correlation between HCV core antigen and HCV RNA (r(2) = 0.781). The negative predictive value of HCV core antigen testing in predicting nonresponse at weeks 4 and 12 were 75 and 100%, and for undetectable or a 2-log drop in HCV RNA were 69.6 and 75% respectively. HCV core antigen detection is quick, and easy to perform alternative to HCV RNA, and could be used as a marker of HCV viraemia for monitoring the progress of therapy.

Evaluation of a commercial enzyme immunoassay for HIV screening in urine.

A cross-sectional study was conducted to evaluate the utility of a commercial enzyme immunoassay (EIA) as a screening test for detecting HIV-1 antibody in urine in a population at risk for HIV infection in Catalonia, Spain. Paired urine and serum samples were collected consecutively from 99 patients who attended two drug-dependency treatment centres and 151 patients who attended a sexually transmitted diseases (STD) clinic in Barcelona. Antibodies against HIV in urine samples were detected using the Calypte HIV-1 Urine EIA (Calypte Biomedical Corporation, Berkeley, CA, USA) and confirmed by urine-based Western blot (WB) analysis. Sera were analysed using Bioelisa HIV-1+2 EIA (Biokit Laboratories, Barcelona, Spain), and the results were verified using serum-based WB analysis. Results of both urine and serum testing were available for 246 of 250 participants. For 52 individuals the results of both urine and serum testing were positive and for five the results were discordant (2 with urine-negative/serum-positive results and 3 with urine-positive/serum-negative results). The respective sensitivity and specificity values obtained for the urine EIA were 100% and 96.2% for intravenous drug users (IDUs) and 80% and 99.3% for persons attending the STD clinic. According to the 1997 UNAIDS/WHO strategy I recommendations, these values are acceptable for surveillance purposes, particularly in populations with a high prevalence of HIV infection.

Assessment of a new test to detect Legionella urinary antigen for the diagnosis of Legionnaires' Disease.

Given that the rate of mortality by Legionella pneumonia increases in incorrectly treated patients, rapid diagnosis and early antibiotic treatment are needed. We have assessed the performance of a new enzyme immunoassay (EIA) test (Bartels Inc. Trinity Biotech Company, Wicklow, Ireland) to detect Legionella pneumophila antigen in urine comparing it to Binax EIA (Binax, Portland, Maine). We also evaluated the capability of both EIAs to detect extracted soluble antigens of Legionella strains. Using nonconcentrated urine samples (NCU) the sensitivity of Bartels EIA was 74.1% (66/89) and the sensitivity of Binax EIA was 51.7% (46/89). The sensitivity of both EIA tests were 91.5% (54/59) using concentrated urine samples (CU). Specificity of both EIA tests was 100% in NCU and CU. Bartels EIA was able to detect all serogroup L. pneumophila antigens, achieving a higher sensitivity in the case of L. pneumophila serogroup 1 soluble antigen. The new EIA was found to be a useful test for the rapid diagnosis of Legionella pneumonia, being a better alternative to the Binax EIA if NCU is used.

[Pneumonias in patients with malignant hemopathies. Their etiology, response to treatment and prognostic factors in 69 patients (88 episodes)]. / Neumonías en los pacientes con hemopatías malignas. Etiología, respuesta al tratamiento y factores pronósticos en 69 pacientes (88 episodios).

BACKGROUND: To analyze the etiology, treatment response and prognostic factors in 88 episodes of pneumonia in patients with hematological malignancies diagnosed in one center during a period of 30 months. PATIENTS AND METHODS: 88 episodes of pneumonia in 69 adult patients were studied. Age, sex, hematological malignancy and its treatment, existence of neutropenia and hypogammaglobulinemia, administration of immunosuppressive agents, type (hospital or community-acquired) and localization of pneumonia, presence of respiratory failure and treatment response were reported. For etiologic diagnosis of pneumonias, cultures of blood, sputum, pleural fluid and bronchoalveolar lavage (BAL), as well as Legionella pneumophila, Aspergillus fumigatus and Streptococcus pneumoniae antigen detection in urine were performed. Univariate and multivariate analyses of prognostic factors for pneumonia evolution were carried out. RESULTS: The median age was 63 years. Acute leukemias (AL) were the predominant hematological malignancies. Microbiologic documentation was obtained in 40 (45%) of pneumonias. Fiberoptic bronchoscopy with BAL (71%) was the diagnostic procedure with highest yield followed by blood cultures (25%). Streptococcus pneumoniae (13) was the most frequent isolated pathogen, followed by Legionella pneumophila (6) and Pseudomonas aeruginosa (6). A significantly higher prevalence of Streptococcus pneumoniae was observed in community-acquired pneumonia. The overall mortality rate was 20%. Respiratory failure (p = 0.0009), existence of neutropenia (p = 0.0023), age equal or higher than 60 years (p = 0.012) and prolonged administration of immunosuppressive agents (p = 0.015) were the prognostic factors associated with unfavourable evolution of pneumonias in the multivariate analysis. CONCLUSIONS: The etiologic diagnosis of pneumonia in patients with hematological malignancies was only achieved in a half of cases. In our series, the high prevalence of Legionella pneumophila can be attributed to the special epidemiologic characteristics of our hospital. Prognostic factors of pneumonia are related to individual factors as well as to the hematological status of patients.

Evaluation of a rapid immunochromatographic assay for the detection of Legionella antigen in urine samples.

A new immunochromatographic membrane assay for detecting Legionella pneumophila serogroup 1 antigen in urine samples (Binax Now Legionella Urinary Antigen Test; Binax, USA) was evaluated. Its sensitivity, specificity and level of agreement with the Binax enzyme immunoassay were compared using nonconcentrated and concentrated urine samples. The overall agreement between the two tests was 98.1%; the specificity of both was 100%. The sensitivity of the immunochromatographic assay was 55.5% in nonconcentrated urine and 97.2% in concentrated urine in comparison with the enzyme immunoassay, using concentrated urine as the reference test. This immunochromatographic assay screens successfully for Legionella pneumophila serogroup 1 soluble antigen in concentrated urine samples.

Comparison of the Binax Legionella urinary antigen enzyme immunoassay (EIA) with the Biotest Legionella Urin antigen EIA for detection of Legionella antigen in both concentrated and nonconcentrated urine samples.

We evaluated a newly commercial enzyme immunoassay (EIA) (Biotest Legionella Urin Antigen EIA; Biotest AG, Dreieich, Germany) for detection of antigens of all Legionella pneumophila serogroups with a relatively wide spectrum of cross-reactivity as well as antigens of other Legionella spp. by comparing its sensitivity and specificity with those of an EIA for detection of L. pneumophila serogroup 1 antigen (Legionella urinary antigen EIA; Binax, Portland, Maine). Both tests were performed with both concentrated and nonconcentrated urine samples. We also evaluated the capabilities of both EIAs to detect extracted soluble antigens of American Type Culture Collection (ATCC) Legionella strains (L. pneumophila serogroups 1 to 14, L. bozemanii, and L. longbeachae). The sensitivity of the Biotest EIA was 66.66% in nonconcentrated urine and 86.66% in concentrated urine. The sensitivity of the Binax EIA was 63.76% and 88.88% in nonconcentrated and concentrated urine, respectively. The specificity was 100% in nonconcentrated and concentrated urine for both assays. The Binax EIA and Biotest EIA detected extracted soluble antigens of L. pneumophila serogroups 1 to 14 and L. bozemanii ATCC strains. The cross-reactions observed with the Binax EIA were probably due to common epitopes directly related to lipopolysaccharide. Further studies are required to determine the usefulness of the Binax EIA for detection of urinary antigens from Legionella species and serogroups other than L. pneumophila serogroup 1. The Biotest EIA proved to be as rapid, sensitive, and specific as the Binax EIA for the diagnosis of legionellosis. Concentration of antigen present in urine increased the sensitivities of both techniques with no reduction in specificity.

Detection and identification of mycobacteria by amplification of RNA and DNA in pretreated blood and bone marrow aspirates by a simple lysis method.

A sodium dodecyl (lauryl) sulfate method was evaluated for the preparation of blood specimens and bone marrow aspirates for use in two amplification procedures (Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test [AMTDT] and Roche Amplicor M. avium/M. intracellulare [MAI] Test) for the detection and identification of Mycobacterium tuberculosis and M. avium and M. intracellulare, respectively. The AMTDT is based on amplification of rRNA, whereas the Amplicor MAI Test amplifies a specific DNA region of the 16S rRNA gene. The results of amplification techniques were compared with those of standard culture and culture in BACTEC 13A and BACTEC 12B liquid media. A total of 121 blood specimens and 15 bone marrow aspirates were collected from 136 AIDS patients. Mycobacterial growth was recovered for 103 specimens; 35 yielded M. tuberculosis, 62 yielded M. avium, 5 yielded M. genavense, and 1 yielded M. kansasii. The values of sensitivity and specificity in pretreated specimens for detection of M. tuberculosis by the AMTDT were 94.3 and 100%, respectively, and those for detection of M. avium by the Amplicor MAI Test were 91.9 and 100%, respectively. The simple lysis method described in the present work allows the recovery of mycobacteria from blood specimens and bone marrow aspirates and may be used in combination with the AMTDT and the Amplicor MAI Test to detect and identify different members of the genus Mycobacterium. This method might also be applicable for the identification of mycobacteria from blood culture fluids with acridinium-ester-labeled DNA probes.