American journal of clinical pathology最新文献

Objectives: Acute infectious diseases are some of the most common reasons for receiving medical care, and analysis of the host immune response is an attractive approach for their diagnosis. The present study aimed to evaluate the potential usefulness of CD169 expression on peripheral monocytes (mCD169) as a marker of viral-associated host immune response.

Methods: In a large mono-institutional cohort of 4,025 patients evaluated for SARS-CoV-2 (CoV2) and other viral infections, mCD169 analysis was performed by rapid flow cytometry assay.

Results: Increased mCD169 values (median, 17.50; IQR, 8.40-25.72) were found in 1,631 patients with CoV2+ acute infection compared to 2,394 in CoV2- patients (median, 2.35; IQR, 2.0-3.25) (odds ratio [OR], 21.84; 95% CI ,17.53-27.21; P < .001). Among CoV2- patients, 1,484 (62.0%) were assessed for other viral infections, and viral etiology was laboratory confirmed in 428 patients (CoV2- Vir+), with RNA viruses most frequently detected (94.6%). Higher levels of mCD169 were also confirmed in CoV2- Vir+ compared to CoV2- Vir- patients (OR, 10.05; 95% CI, 7.35-13.74; P < .001).

Conclusions: mCD169 analysis by rapid flow cytometry assay may be a sensitive broad marker useful for the rapid triage of patients with suspected acute viral infections and could potentially be directly applied to eventual new emergent viral outbreaks.

Objectives: We sought to assess the performance of 3 laboratory tests on blood specimens for direct detection of Anaplasma phagocytophilum, the cause of human granulocytic anaplasmosis (HGA), in patients tested at a single medical institution in New York State.

Methods: Direct tests included microscopic blood smear examination for intragranulocytic inclusions, polymerase chain reaction (PCR), and culture using the HL-60 cell line. The HGA cases testing positive by only 1 direct test were not included, unless HGA was confirmed by acute or convalescent serology using an indirect immunofluorescent assay.

Results: From 1997 to 2009, 71 patients with HGA were diagnosed by at least 1 of the 3 direct test methods. For the subgroup of 55 patients who were tested using all 3 methods, culture was positive for 90.9% (50/55) vs 81.8% (45/55) for PCR vs 63.6% (35/55) for blood smear (P =.002). Most cultures (79.3%) were detected as positive within 1 week of incubation.

Conclusions: Although using culture to detect A phagocytophilum is likely not amenable for implementation in most hospital laboratories, in our experience, culture had the highest yield among the direct tests evaluated.

Objectives: Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare and aggressive hematologic neoplasm that can show clinical, morphologic, and immunophenotypic overlap with acute myeloid leukemia. Myeloid cell nuclear differentiation antigen (MNDA) is a nuclear protein expressed by myelomonocytic cells previously reported to be reliably absent in BPDCN and proposed as a useful adjunct for the distinction of BPDCN and acute myeloid leukemia. We encountered a case of BPDCN that showed strong nuclear expression of MNDA in bone marrow and breast samples and weak to absent expression in skin samples, prompting us to reevaluate the expression of MNDA in BPDCN.

Methods: We collected all available BPDCN cases from the Stanford University archives collected in the past 10 years and subjected them to MNDA immunohistochemistry. In select cases, molecular profiling by next-generation sequencing was performed.

Results: We found 4 cases (of 8 total examined [50%]) with convincing site-discordant MNDA expression. This expression was seen in 3 of 6 (50%) bone marrow samples, 1 of 2 (50%) breast soft tissue samples, and 3 of 14 (up to 21%) skin samples and was not obviously predicted by age, sex, history of myeloid neoplasm, or treatment history. In 2 cases, MNDA was strongly expressed in 2 distinct sites (breast/bone marrow, skin/bone marrow) and negative in subsequent samples.

Conclusions: Our findings suggest that MNDA expression in BPDCN is anatomic site dependent and transient, with noncutaneous infiltrates showing more frequent expression than cutaneous infiltrates. These results caution against the use of MNDA to exclude BPDCN when considering the differential diagnosis of a blastic extramedullary infiltrate.

Objectives: ROS-1 immunohistochemistry (IHC) is a common method for screening ROS1 fusion in the clinical management of non-small cell lung cancer. The interpretation criteria for ROS-1 SP384 IHC, however, remain unestablished.

Methods: Sixty-five non-small cell lung cancer cases underwent AmoyDx ROS1 fusion real-time polymerase chain reaction (PCR) study and ROS-1 SP384 IHC tests, which were retrieved for analysis. ROS-1 IHC tests were interpreted based on the established classifiers as well as the presence of diffuse homogeneous immunoreactivity. The diagnostic accuracies of these ROS-1 IHC interpretation methods were evaluated by comparing them with the ROS1 real-time PCR results.

Results: Previous ROS-1 IHC classifiers demonstrated high sensitivity for positive ROS1 real-time PCR results (100%), but they showed low specificities (25%-50%) and overall accuracies (58%-72%). In contrast, the diffuse homogeneous ROS-1 immunoreactivity predicted positive ROS1 real-time PCR results with much higher specificity (94%) and overall accuracy (95%), albeit with a slightly lower sensitivity (97%). Some cases that showed discrepancy between diffuse homogeneous ROS-1 immunoreactivity and real-time PCR results involved rare ROS1::LDLR fusion and suboptimal IHC staining.

Conclusions: A 3-tier reporting system for ROS-1 SP384 IHC testing combining previous interpretation criteria and diffuse and homogeneous immunoreactivity may better predict ROS1 fusion status without decreasing specificity.