Norgan, Andrew P.

Cytapheresis (removal of cellular blood components) has been employed for treatment of infectious diseases since the 1960s. Techniques have included thrombocytapheresis (buffy coat apheresis) for loiasis, erythrocytapheresis for malaria and babesiosis, and leukocytapheresis for pertussis‐associated lymphocytosis. Published data on these applications is largely limited to case level data and small observational studies; as such, recommendations for or against the use of cytapheresis in the treatment of infections have been extrapolated from these limited (and at times flawed) data sets. Consequently, utilization of cytapheresis in many instances is not uniform between institutions, and typically occurs at the discretion of treating medical teams. This review revisits the existing literature on the use of cytapheresis in the treatment of four infections (loasis, malaria, babesiosis, and pertussis) and examines the rationale underlying current treatment recommendations concerning its use.

A variety of arthropods, protozoa, and helminths infect the skin and subcutaneous tissues and may be identified by anatomic pathologists in standard cytology and histology preparations. The specific organisms seen vary greatly with the patient’s exposure history, including travel to or residence in endemic countries. Arthropods are the most commonly encountered parasites in the skin and subcutaneous tissues and include Sarcoptes scabei, Demodex species, Tunga penetrans, and myiasis-causing fly larvae. Protozoal parasites such as Leishmania may also be common in some settings. Helminths are less often seen, and include round worms (eg, Dirofilaria spp.), tapeworms (eg, Taenia solium, Spirometra spp.), and flukes (eg, Schistosoma spp.). This review covers the epidemiologic and histopathologic features of common parasitic infections of the skin and subcutaneous tissues.

BACKGROUND Platelet transfusion–refractoriness is a challenging and expensive clinical scenario seen most often in patients with hematologic malignancies. Although the majority of platelet transfusion–refractory cases are due to nonimmune causes, a significant minority are caused by alloimmunization against Class I human leukocyte antigens (HLAs) or human platelet antigens (HPAs). Such platelet transfusion–refractory patients can be effectively managed with appropriate antigen‐negative products. STUDY DESIGN AND METHODS Our institution has developed a diagnostic and management algorithm for the platelet transfusion–refractory patient with an early focus on identifying those cases caused by immune‐mediated factors. Using physical platelet cross‐matches to initially classify platelet transfusion–refractory patients as immune‐mediated or not, cross‐match–compatible inventory is then provided to immune‐mediated patients, whereas subsequent HLA (with or without HPA) testing is performed. RESULTS Our blood donor program performs Class I HLA typing of all repeat platelet donors to facilitate the identification of antigen‐negative platelet units (virtual cross‐matching) as well as the recruitment of HLA‐matched donors. The platelet transfusion–refractoriness algorithm realizes an initial net cost savings once two apheresis platelets are saved from use for each newly identified, immune‐mediated platelet transfusion–refractory patient. CONCLUSION An algorithm utilizing physical platelet cross‐matches, Class I HLA and HPA antibody testing, and upfront Class I HLA typing of platelet donors leads to overall resource savings and improved clinical management for platelet transfusion–refractory patients.

ABSTRACT We describe a 16-year-old neutropenic patient from the Middle East with bloodstream infection caused by two carbapenemase-producing Escherichia coli isolates that we characterized by whole-genome sequencing. While one displayed meropenem resistance and was bla NDM positive, the other demonstrated meropenem susceptibility yet harbored bla OXA181 (which encodes a bla OXA48 -like enzyme). This report highlights the challenge of laboratory detection of bla OXA48 -like enzymes and the clinical implications of genotypic resistance detection in carbapenemase-producing Enterobacteriaceae .

ABSTRACT Resistance to carbapenems in Enterobacteriaceae is a clinical problem of growing significance. Difficulty in treating multidrug-resistant Gram-negative organisms with conventional antibiotics has led to a renewed and increasing use of polymyxin compounds, such as colistin. Here, we report the isolation of carbapenem- and colistin-resistant Enterobacter cloacae from a polymicrobial lower extremity wound in an ambulatory patient. Whole-genome sequencing demonstrated the presence of chromosomal bla IMI-1 and bla AmpC , as well as numerous efflux pump genes.