Colt M. McClain

Enhanced Diagnostic Yields of Bacteremia and Candidemia in Blood Specimens by PCR-Electrospray Ionization Mass Spectrometry

ABSTRACT A prospective study was performed to determine the value of direct molecular testing of whole blood for detecting the presence of culturable and unculturable bacteria and yeasts in patients with suspected bloodstream infections. A total of 464 adult and pediatric patients with positive blood cultures matched with 442 patients with negative blood cultures collected during the same period were recruited during a 10-month study. PCR amplification coupled with electrospray ionization mass spectrometry (PCR-ESI-MS) plus blood culture reached an overall agreement of 78.6% in the detection and species-level identification of bacterial and candidal pathogens. Of 33 culture-negative/PCR-ESI-MS-positive specimens, 31 (93.9%) were judged to be truly bacteremic and/or candidemic based on a medical chart review and analytical metrics. Among the 15 culture-positive specimens in which PCR-ESI-MS detected additional bacterial or yeast species, 66.7% and 20.0% of the additional positive specimens by PCR-ESI-MS were judged to be truly or possibly bacteremic and/or candidemic, respectively. Direct analysis of blood samples by PCR-ESI-MS rapidly detects bacterial and yeast pathogens in patients with bloodstream infections. When used in conjunction with blood culture, PCR-ESI-MS enhances the diagnostics of septicemia by shortening test turnaround time and improving yields.

Mdm2 and Aurora Kinase A Inhibitors Synergize to Block Melanoma Growth by Driving Apoptosis and Immune Clearance of Tumor Cells

Therapeutics that induce cancer cell senescence can block cell proliferation and promote immune rejection. However, the risk of tumor relapse due to senescence escape may remain high due to the long lifespan of senescent cells that are not cleared. Here, we show how combining a senescence-inducing inhibitor of the mitotic kinase Aurora A (AURKA) with an MDM2 antagonist activates p53 in senescent tumors harboring wild-type 53. In the model studied, this effect is accompanied by proliferation arrest, mitochondrial depolarization, apoptosis, and immune clearance of cancer cells by antitumor leukocytes in a manner reliant upon Ccl5, Ccl1, and Cxcl9. The AURKA/MDM2 combination therapy shows adequate bioavailability and low toxicity to the host. Moreover, the prominent response of patient-derived melanoma tumors to coadministered MDM2 and AURKA inhibitors offers a sound rationale for clinical evaluation. Taken together, our work provides a preclinical proof of concept for a combination treatment that leverages both senescence and immune surveillance to therapeutic ends.

Passage-dependent cancerous transformation of human mesenchymal stem cells under carcinogenic hypoxia

Bone marrow‐derived human mesenchymal stem cells (hMSCs) either promote or inhibit cancer progression, depending on factors that heretofore have been undefined. Here we have utilized extreme hypoxia (0.5% O2) and concurrent treatment with metal carcinogen (nickel) to evaluate the passage‐dependent response of hMSCs toward cancerous transformation. Effects of hypoxia and nickel treatment on hMSC proliferation, apoptosis, gene and protein expression, replicative senescence, reactive oxygen species (ROS), redox mechanisms, and in vivo tumor growth were analyzed. The behavior of late passage hMSCs in a carcinogenic hypoxia environment follows a profile similar to that of transformed cancer cells (i.e., increased expression of oncogenic proteins, decreased expression of tumor suppressor protein, increased proliferation, decreased apoptosis, and aberrant redox mechanisms), but this effect was not observed in earlier passage control cells. These events resulted in accumulated intracellular ROS in vitro and excessive proliferation in vivo. We suggest a mechanism by which carcinogenic hypoxia modulates the activity of three critical transcription factors (c‐MYC, p53, and HIF1), resulting in accumulated ROS and causing hMSCs to undergo cancer‐like behavioral changes. This is the first study to utilize carcinogenic hypoxia as an environmentally relevant experimental model for studying the age‐dependent cancerous transformation of hMSCs.— Crowder, S. W., Horton, L. W., Lee, H. H., McClain, C. M., Hawkins, O. E., Palmer, A. M. Bae, H., Richmond, A., Sung, H.‐J. Passage‐dependent cancerous transformation of human mesenchymal stem cells under carcinogenic hypoxia. FASEB J. 27, 2788‐2798 (2013). www.fasebj.org

Fibrous hamartoma of infancy: a clinicopathologic analysis of 60 cases.

Fibrous hamartoma of infancy is a benign soft tissue tumor with a characteristic triphasic organoid histologic appearance. It typically occurs within the first 2 years of life. The usual anatomic locations include the upper extremities, axilla, and upper back. Diagnostic challenges occur when this tumor arises in older children, outside of the usual anatomic sites, or when unusual histologic features are encountered. This study reports 60 cases of fibrous hamartoma of infancy from institutional and consultation files. All had a triphasic organoid histologic pattern, but half also displayed an unusual pseudoangiomatous histologic pattern. The male to female ratio was 2.0 (40 boys, 20 girls), with a mean age of 1.5 years (range, 16 d to 8 y) at diagnosis. Tumor size ranged from 0.5 to 9 cm, with a mean of 3.7 cm. Sites included the trunk (40 cases), extremities (17 cases), and head and neck (3 cases). All cases had triphasic elements of mature fibrous tissue, mature adipose tissue, and immature mesenchymal tissue in varying proportions, with the additional pseudoangiomatous pattern in 32 cases. Immunohistochemical analysis demonstrated reactivity for smooth muscle actin and CD34 in the mature fibrous tissue, S100 protein in the mature adipose tissue, and variable CD34 reactivity in immature mesenchymal and pseudoangiomatous foci. Ki-67 proliferative activity was noted in the immature mesenchymal and pseudoangiomatous foci, and Bcl-2 reactivity was restricted to mesenchymal and pseudoangiomatous foci. Follow-up information in 12 cases revealed no evidence of recurrence in 10 patients and local recurrence in 2 patients, each at 3.5 years after primary excision. This study demonstrates an expanded age range (up to 8 y) and anatomic distribution (30 cases outside of the classic locations of the upper extremities, axilla, and upper back) of fibrous hamartoma of infancy. The pseudoangiomatous morphologic variation can lead to challenges in diagnosis and may reflect a maturational phenomenon from the immature mesenchymal component.

Kikuchi-Fujimoto lymphadenitis: role of parvovirus B-19, Epstein-Barr virus, human herpesvirus 6, and human herpesvirus 8

Kikuchi-Fujimoto lymphadenitis is a self-limited disorder that typically presents in young females as painless cervical lymphadenopathy with fever, anemia, and leukopenia. The clinical manifestations and pathologic findings suggest a viral etiology, yet specific etiologic agents remain unknown. Although there are studies reporting positive associations between Kikuchi-Fujimoto lymphadenitis and parvovirus B19 and herpesviruses, other studies have failed to find an association with these viruses. To our knowledge, this current study is the largest study of Kikuchi-Fujimoto lymphadenitis in Western patients that used polymerase chain reaction testing for 4 different common viral pathogens often implicated as etiologic agents in Kikuchi-Fujimoto lymphadenitis. Archival material from 3 institutions was included, following confirmation of the diagnosis of Kikuchi-Fujimoto lymphadenitis by 2 independent pathologists. Polymerase chain reaction from the paraffin-embedded tissue sections for parvovirus B19, Epstein-Barr virus, human herpesvirus 6, and human herpesvirus 8 was performed. Eighteen cases of Kikuchi-Fujimoto lymphadenitis were analyzed, 12 of which (60%) were cervical lymph nodes. All the cases showed typical geographic necrosis with abundant apoptotic debris, although the degree of necrosis was variable. Polymerase chain reaction revealed a high prevalence of parvovirus B19 in the controls (44%); there were fewer positive cases seen in the Kikuchi-Fujimoto lymphadenitis cases (11%), but this did not reach statistical significance (P = .25).There were no significant differences between cases and controls in the prevalence of Epstein-Barr virus, human herpesvirus 6, and human herpesvirus 8 (P = .50 for all 3). Polymerase chain reaction failed to reveal a positive association between Kikuchi-Fujimoto lymphadenitis and 4 common suspected viral agents. These findings do not support a role for Epstein-Barr virus, human herpesvirus 6, human herpesvirus 8, or parvovirus B19 in the pathogenesis of Kikuchi-Fujimoto lymphadenitis.

Alveolar soft part sarcoma and granular cell tumor: an immunohistochemical comparison study

Although the histologic features of alveolar soft part sarcoma and granular cell tumor are typically distinctive, occasional cases show a significant morphologic overlap. Differentiating these entities is crucial because granular cell tumor is almost always benign and alveolar soft part sarcoma is invariably malignant. We evaluated a panel of immunohistochemical stains (S-100 protein, inhibin, SOX10, nestin, calretinin, and TFE3) in 13 alveolar soft part sarcomas and 11 granular cell tumors. Tissue sections were also stained by the periodic acid-Schiff method after diastase digestion (PAS-D) and evaluated for coarse cytoplasmic granularity or crystalline cytoplasmic inclusions. S-100 protein, inhibin, SOX10, and nestin each distinguished granular cell tumor and alveolar soft part sarcoma with 100% sensitivity and specificity. PAS-D staining also distinguished cases with 100% accuracy, as granular cell tumor consistently demonstrated coarsely granular, PAS-D-positive cytoplasm and alveolar soft part sarcoma showed only focal intracytoplasmic crystalline inclusions. Although all granular cell tumors were calretinin positive, so were 46% of alveolar soft part sarcomas. TFE3 was positive in 91% of granular cell tumors and all alveolar soft part sarcomas. Together with PAS-D, immunohistochemical stains for S-100 protein, inhibin, SOX10, and nestin accurately identify alveolar soft part sarcoma and granular cell tumor. Although TFE3 has been reported as a relatively specific marker for alveolar soft part sarcoma, it should be recalled that it is also expressed in most granular cell tumors.

Blood ordering from the operating room: turnaround time as a quality indicator

BACKGROUND: Quality indicators in transfusion medicine are necessary for patient safety and customer satisfaction. The turnaround time (TAT) of issuing red blood cells (RBCs) has emerged as a quality indicator but is not an established benchmark. We examined the TAT for issuing RBCs from the blood bank to the operating rooms (ORs) at Vanderbilt University Medical Center (VUMC) and Stanford University Medical Center (SUMC).

Localized cutaneous argyria: two case reports and clinicopathologic review.

We report 2 cases of patients who presented with blue macules clinically suspicious for blue nevi. One patient had no documented history of trauma or silver exposure, and the other reported exposure to silver over 30 years ago. Microscopic examination revealed a dermal population of brown-black globules predominantly adhering to collagen fibers. In both cases, no melanocytic proliferation was identified by immunohistochemistry. Analysis of the skin biopsies with scanning electron microscopy and energy dispersive x-ray spectroscopy demonstrated the presence of silver and selenium. These findings were diagnostic of localized cutaneous argyria. Our case reports highlight the importance of including localized cutaneous argyria in the differential diagnosis of pigmented lesions.

Coccidioides, Cryptococcus, or Blastomyces? A Diagnostic Dilemma Encountered During Frozen Section Evaluation

Intraoperative consultation via frozen section is an important part of modern day surgical pathology. Recognizing fungi in tissues on frozen and permanent sections is not always a simple task, and correctly identifying the agent can be a significant challenge, even for experienced microscopists. We present a case of a 17-year-old boy with chronic osteomyelitis involving the right proximal ulna. During an irrigation and debridement operation, a frozen section was sent to surgical pathology for evaluation. A limited patient history coupled with sparse organisms present in the frozen section led to the diagnosis of fungal osteomyelitis, favor Coccidioides. Follow-up permanent sections with special staining and successful fungal culture clarified the causal agent to be Blastomyces dermatitidis. The role of frozen sections is not to perfectly speciate the fungal pathogen but to describe the morphology and infectious process and provide a differential diagnosis of the candidate fungi. The importance of intraoperative culture in infectious cases cannot be understated, and it is the responsibility of pathologists to inform surgeons that tissue is needed for culture. A brief overview of Blastomyces, including histopathologic features and key microscopic differences from Coccidioides and Cryptococcus, is discussed.

PI3K Inhibition Reduces Mammary Tumor Growth and Facilitates Antitumor Immunity and Anti-PD1 Responses

Purpose: Metastatic breast cancers continue to elude current therapeutic strategies, including those utilizing PI3K inhibitors. Given the prominent role of PI3Kα,β in tumor growth and PI3Kγ,δ in immune cell function, we sought to determine whether PI3K inhibition altered antitumor immunity. Experimental Design: The effect of PI3K inhibition on tumor growth, metastasis, and antitumor immune response was characterized in mouse models utilizing orthotopic implants of 4T1 or PyMT mammary tumors into syngeneic or PI3Kγ-null mice, and patient-derived breast cancer xenografts in humanized mice. Tumor-infiltrating leukocytes were characterized by IHC and FACS analysis in BKM120 (30 mg/kg, every day) or vehicle-treated mice and PI3Kγnull versus PI3KγWT mice. On the basis of the finding that PI3K inhibition resulted in a more inflammatory tumor leukocyte infiltrate, the therapeutic efficacy of BKM120 (30 mg/kg, every day) and anti-PD1 (100 μg, twice weekly) was evaluated in PyMT tumor–bearing mice. Results: Our findings show that PI3K activity facilitates tumor growth and surprisingly restrains tumor immune surveillance. These activities could be partially suppressed by BKM120 or by genetic deletion of PI3Kγ in the host. The antitumor effect of PI3Kγ loss in host, but not tumor, was partially reversed by CD8+ T-cell depletion. Treatment with therapeutic doses of both BKM120 and antibody to PD-1 resulted in consistent inhibition of tumor growth compared with either agent alone. Conclusions: PI3K inhibition slows tumor growth, enhances antitumor immunity, and heightens susceptibility to immune checkpoint inhibitors. We propose that combining PI3K inhibition with anti-PD1 may be a viable therapeutic approach for triple-negative breast cancer. Clin Cancer Res; 23(13); 3371–84. ©2016 AACR.