Infection with Babesia microti can cause severe illness, particularly among asplenic individuals. Blacklegged and Western blacklegged ticks (Ixodes scapularis and Ixodes pacificus, respectively) are the vector through which B microti is transmitted. The distribution of these ticks in Canada has increased over the past several years. In this article, the authors present the first case of babesiosis in Canada that was not diagnosed following travel to an area in which the disease is endemic.

Although KIT mutations are present in 20–25% of cases of t(8;21)(q22;q22) acute myeloid leukemia (AML), concurrent development of systemic mastocytosis (SM) is exceedingly rare. We examined the clinicopathologic features of SM associated with t(8;21)(q22;q22) AML in ten patients (six from our institutions and four from published literature) with t(8;21) AML and SM. In the majority of these cases, a definitive diagnosis of SM was made after chemotherapy, when the mast cell infiltrates were prominent. Deletion 9q was an additional cytogenetic abnormality in four cases. Four of the ten patients failed to achieve remission after standard chemotherapy and seven of the ten patients have died of AML. In the two patients who achieved durable remission after allogeneic hematopoietic stem cell transplant, recipient-derived neoplastic bone marrow mast cells persisted despite leukemic remission. SM associated with t(8;21) AML carries a dismal prognosis; therefore, detection of concurrent SM at diagnosis of t(8;21) AML has important prognostic implications.

No abstract

No abstract

The role of histologic examination in lymphoma diagnosis has been called into question by proponents of new technologies, such as genomics and proteomics. We review the history and salient features of morphologic evaluation in lymphoid diseases, and discuss the general and specific limitations of mature ancillary techniques, such as immunohistochemistry, flow cytometry, and molecular studies. We then speculate on the future relationship between morphology and the new genomic and proteomic technologies as they become integrated into clinical practice.

No abstract

We describe the validation of a test for the quantification of Epstein-Barr virus (EBV) DNA (viral load) using the Artus EBV TM PCR analyte-specific reagent (ASR; QIAGEN Hamburg, Hamburg, Germany). A dilution series demonstrated a limit of detection of 2.25 log(10) copies/mL (>95% positivity rate). The limit of quantification was 3.90 log(10) copies/mL based on an SD of less than 0.15. The assay was linear from 2.17 to 6.2 log(10) copies/mL. Low (3.70 log(10) copies/mL) and high (5.40 log(10) copies/mL) patient samples had coefficients of variation (CVs) of 2.0% and 1.4%, respectively. The cycle thresholds of 4 points used to generate the standard curve had CVs ranging from 0.8% to 1.6%. A comparison of 35 matched samples showed a small positive bias (0.35 log(10) copies/mL) for the Artus ASR relative to a laboratory-developed EBV viral load assay targeting the Bam H1-W region of the EBV genome.

We describe the case of a 13-year-old girl with an apparently de novo unbalanced translocation resulting in the presence of additional chromosomal material on the short arm of one X chromosome, which was detected by conventional G-banding studies. Fluorescence in situ hybridization (FISH) using the Chromoprobe Multiprobe-M protocol confirmed that the additional chromosomal material originated from chromosome 5. The karyotype of this patient is now established to be 46,X,der(X) t(X;5)(p22.3;q33), with a deletion of Xp22.3-pter and partial trisomy of 5q33-qter. The distal 5q trisomy genotype has been associated with clinical signs that include growth and mental retardation, eczema, craniofacial anomalies, and malformations of heart, lungs, abdomen, limbs, and genitalia. Our patient also has short stature, a prominent nasal bridge, a flat philtrum, a thin upper lip, dental caries, and limb and cardiac malformations, but she appears to be mildly affected compared with previously reported cases. This is the first case of distal 5q trisomy arising from a translocation with the X chromosome. Replication studies on this patient show that the derivative t(X;5) chromosome is late replicating in almost all cells examined, which indicates that this chromosome is preferentially inactivated. However, the translocated segment of chromosome 5 appears to be early replicating, which implies that the trisomic 5q segment is transcriptionally active. We cannot determine from these studies whether all or only some genes in this segment are expressed, but this patient's relatively mild clinical signs suggest that the critical region(s) that contribute to the distal 5q trisomy phenotype are at least partly suppressed. A review of other patients with X-chromosome translocations indicates that many but not all of them also have attenuated phenotypes. The mechanism of inactivation of autosomal material attached to the X chromosome is complex, with varying effects on the phenotype of the patients that depend on the nature of the autosomal chromatin. Replication studies are of limited utility in predicting expression of autosomal genes involved in X-chromosome translocations.