Quantitative PCR to diagnose Pneumocystis pneumonia in immunocompromised non-HIV patients.

The utility of quantitative Pneumocystis jirovecii PCR in clinical routine for diagnosing Pneumocystis pneumonia (PCP) in immunocompromised non-HIV patients is unknown. We analysed bronchoalveolar lavage fluid with real-time quantitative P. jirovecii PCR in 71 cases with definitive PCP defined by positive immunofluorescence (IF) tests and in 171 randomly selected patients with acute lung disease. In those patients, possible PCP cases were identified by using a novel standardised PCP probability algorithm and chart review. PCR performance was compared with IF testing, clinical judgment and the PCP probability algorithm. Quantitative P. jirovecii PCR values >1,450 pathogens·mL(-1) had a positive predictive value of 98.0% (95% CI 89.6-100.0%) for diagnosing definitive PCP. PCR values of between 1 and 1,450 pathogens·mL(-1) were associated with both colonisation and infection; thus, a cut-off between the two conditions could not be identified and diagnosis of PCP in this setting relied on IF and clinical assessment. Clinical PCP could be ruled out in 99.3% of 153 patients with negative PCR results. Quantitative PCR is useful for diagnosing PCP and is complementary to IF. PCR values of >1,450 pathogens·mL(-1) allow reliable diagnosis, whereas negative PCR results virtually exclude PCP. Intermediate values require additional clinical assessment and IF testing. On the basis of our data and for economic and logistical limitations, we propose a clinical algorithm in which IF remains the preferred first test in most cases, followed by PCR in those patients with a negative IF and strong clinical suspicion for PCP.

[The Advanced Breast Biopsy Instrumentation (ABBI) for evaluation of mammographically suspicious, non-palpable findings of the breast: a reliable diagnosis with minor therapeutic potential]. / Die Advanced Breast Biopsy Instrumentation (ABBI) für die Evaluation mammographisch verdächtiger, nicht-palpabler Befunde der Brustdrüse: Eine zuverlässige Diagnostik mit geringem therapeutischen Potential.

BACKGROUND: Stereotactic biopsy techniques supersede conventional hook-wire localization followed by open excision to clarify the dignity of nonpalpable mammographic lesions. The advanced breast biopsy instrumentation (ABBI) allows stereotactically guided excision of a specimen up to 20 mm in diameter on an outpatient basis under local anaesthesia. METHODS: Demographic information, mammographic and pathological findings, complications, subsequent interventions and sensitivity as well as efficiency of a series of 144 planned ABBI procedures were documented (largest published single institution series). RESULTS: The ABBI procedure was successfully performed in 93.8% (135/144); accurate diagnosis was made in 99.3% (134/135), sensitivity for malignant lesions was 96.9% (31/32) and morbidity was 1.5%. Consistent with other published series margins of the biopsy cylinder containing a malignant lesion were involved in 83.9% (26/31). CONCLUSIONS: Excisional biopsy using the ABBI system is a reliable diagnostic tool with a low incidence of morbidity. The therapeutic use is of limited potential.