Purpose In leukemic CTCL (L-CTCL) malignant T cells accumulate in the blood and give rise to widespread skin inflammation. Patients have intense pruritus, increased IgE, decreased Th1 responses and most die from infection. Depleting malignant T cells while preserving normal immunity is a clinical challenge. L-CTCL has been variably described as a malignancy of regulatory, Th2 and Th17 cells. Experimental design We analyzed phenotype and cytokine production in malignant and benign L-CTCL T cells, characterized the effects of malignant T cells on healthy T cells and studied the immunomodulatory effects of treatment modalities in L-CTCL patients. Results 12/12 L-CTCL patients overproduced Th2 cytokines. Remaining benign T cells were also strongly Th2 biased, suggesting a global Th2 skewing of the T cell repertoire. Culture of benign T cells away from the malignant clone reduced Th2 and enhanced Th1 responses but separate culture had no effect on malignant T cells. Co-culture of healthy T cells with L-CTCL T cells reduced IFNγ production and neutralizing antibodies to IL-4 and IL-13 restored Th1 responses. In patients, enhanced Th1 responses were observed following a variety of treatment modalities that reduced malignant T cell burden. Conclusions A global Th2 bias exists in both benign and malignant T cells in L-CTCL and may underlie the infectious susceptibility of patients. Th2 cytokines from malignant cells strongly inhibited Th1 responses. Our results suggest therapies that inhibit Th2 cytokine activity, by virtue of their ability to improve Th1 responses, may have the potential to enhance both anti-cancer and anti-pathogen responses.

Merkel cell carcinomas (MCC) are rare but highly malignant skin cancers associated with a novel polyomavirus. MCC tumors were infiltrated by T cells, including effector, central memory and regulatory T cells. Infiltrating T cells showed markedly reduced activation as evidenced by reduced expression of CD69 and CD25. Treatment of MCC tumors in vitro with IL-2 and IL-15 led to T cell activation, proliferation, enhanced cytokine production and loss of viable tumor cells from cultures. Expanded tumor-infiltrating lymphocytes showed TCR repertoire skewing and upregulation of CD137. MCC tumors implanted into immunodeficient mice failed to grow unless human T cells in the tumor grafts were depleted with denileukin diftitox, suggesting tumor-specific T cells capable of controlling tumor growth were present in MCC. Both CD4+ and CD8+ FOXP3+ regulatory T cells were frequent in MCC. 50% of non-activated T cells in MCC expressed PD-1, a marker of T-cell exhaustion, and PD-L1 and PD-L2 were expressed by a subset of tumor dendritic cells and macrophages. In summary, we observed tumor-specific T cells with suppressed activity in MCC tumors. Agents that stimulate T cell activity, block Treg function or inhibit PD-1 signaling may be effective in the treatment of this highly malignant skin cancer.

Clinical laboratory testing routinely provides actionable results, which help direct patient care in the inpatient and outpatient settings. Since December 2019, a novel coronavirus (SARS-CoV-2) has been causing disease (COVID-19 [coronavirus disease 2019]) in patients, beginning in China and now extending worldwide. In this context of a novel viral pandemic, clinical laboratories have developed multiple novel assays for SARS-CoV-2 diagnosis and for managing patients afflicted with this illness. These include molecular and serologic-based tests, some with point-of-care testing capabilities. Herein, we present an overview of the types of testing available for managing patients with COVID-19, as well as for screening of potential plasma donors who have recovered from COVID-19.

Background Roughly, 10% of elderly patients develop postoperative cognitive dysfunction. General anesthesia impairs spatial memory in aged rats, but the mechanism is not known. Hippocampal neurogenesis affects spatial learning and memory in rats, and isoflurane affects neurogenesis in neonatal and young adult rats. We tested the hypothesis that isoflurane impairs neurogenesis and hippocampal function in aged rats. Methods Isoflurane was administered to 16-month-old rats at one minimum alveolar concentration for 4 h. FluoroJade staining was performed to assess brain cell death 16 h after isoflurane administration. Dentate gyrus progenitor proliferation was assessed by bromodeoxyuridine injection 4 days after anesthesia and quantification of bromodeoxyuridine +cells 12 h later. Neuronal differentiation was studied by determining colocalization of bromodeoxyuridine with the immature neuronal marker NeuroD 5 days after anesthesia. New neuronal survival was assessed by quantifying cells coexpressing bromodeoxyuridine and the mature neuronal marker NeuN 5 weeks after anesthesia. Four months after anesthesia, associative learning was assessed by fear conditioning. Spatial reference memory acquisition and retention was tested in the Morris Water Maze. Results Cell death was sporadic and not different between groups. We did not detect any differences in hippocampal progenitor proliferation, neuronal differentiation, new neuronal survival, or in any of the tests of long-term hippocampal function. Conclusion In aged rats, isoflurane does not affect brain cell death, hippocampal neurogenesis, or long-term neurocognitive outcome.

Objective To review cases and increase awareness in clinicians treating patients who may be taking biotin. Methods We describe the presentation and workup of a woman with secondary progressive multiple sclerosis on high dose biotin with laboratory studies suggestive of thyrotoxicosis. Results Plasma samples showed laboratory evidence of elevated thyroid hormone levels with elevated free thyroxine >7.8 ng/dl (reference interval (RI) 0.9-1.7 ng/dl) and decreased thyroid stimulating hormone <0.02 uIU/ml (RI 0.50-5.70 uIU/ml). Laboratory values normalized when biotin was withheld prior to repeat testing. Conclusions Our case report demonstrates that ingestion of high dose biotin in multiple sclerosis patients can cause interference with laboratory assessment of thyroid function. This interference causes laboratory values suggestive of thyrotoxicosis and can lead to unnecessary evaluation. Clinicians should be aware of the risk of laboratory interference in this patient demographic.

The circulating precursor cells that give rise to human resident memory T cells (T RM ) are poorly characterized. We used an in vitro differentiation system and human skin–grafted mice to study T RM generation from circulating human memory T cell subsets. In vitro T RM differentiation was associated with functional changes, including enhanced IL-17A production and FOXP3 expression in CD4 + T cells and granzyme B production in CD8 + T cells, changes that mirrored the phenotype of T cells in healthy human skin. Effector memory T cells (T EM ) had the highest conversion rate to T RM in vitro and in vivo, but central memory T cells (T CM ) persisted longer in the circulation, entered the skin in larger numbers, and generated increased numbers of T RM . In summary, T CM are highly efficient precursors of human skin T RM , a feature that may underlie their known association with effective long-term immunity.

Purpose We report a case a pediatric patient with an eyelid lesion found to be a basaloid follicular hamartoma. Observations A six-year-old female with juvenile diabetes who presented with a benign eyelid lesion harboring an aberrant eyelash. Conclusions and Importance Basaloid follicular hamartoma is a rare benign neoplasm arising from hair follicles. These lesions can resemble basal cell carcinomas and require complete excision.

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