Stromal cells control the epithelial residence of DCs and memory T cells by regulated activation of TGF-ß.

Cells of the immune system that reside in barrier epithelia provide a first line of defense against pathogens. Langerhans cells (LCs) and CD8(+) tissue-resident memory T cells (TRM cells) require active transforming growth factor-ß1 (TGF-ß) for epidermal residence. Here we found that integrins αvß6 and αvß8 were expressed in non-overlapping patterns by keratinocytes (KCs) and maintained the epidermal residence of LCs and TRM cells by activating latent TGF-ß. Similarly, the residence of dendritic cells and TRM cells in the small intestine epithelium also required αvß6. Treatment of the skin with ultraviolet irradiation decreased integrin expression on KCs and reduced the availability of active TGF-ß, which resulted in LC migration. Our data demonstrated that regulated activation of TGF-ß by stromal cells was able to directly control epithelial residence of cells of the immune system through a novel mechanism of intercellular communication.

Handling the different requirements for commercial and investigational MNC collections by apheresis.

BACKGROUND: With the success of chimeric antigen receptor T-cell (CAR-T) and similar cellular-based therapies, the demand for collection of autologous mononuclear cells by apheresis (MNC(A)) from blood by apheresis has increased. From an apheresis technical standpoint, the collection of MNC(A) is relatively straightforward, especially when compared with collection of hematopoietic progenitor cells (HPC(A)). Most of the collection for MNC(A) are performed for the commercial entities, who use the product for manufacturing cellular therapeutics. We have noticed discrepancies in the handling and apheresis processes required by different companies in obtaining essentially the same product (all companies in the study manufacture CAR-T-based products). We have analyzed the MNC collection requirements from all FDA-approved CAR-T cellular products and some investigational products collected at University of Nebraska Medical Center. We identified discrepancies in the process and suggested mitigation strategies. METHODS: Step-by-step analysis of the collection requirements. Review of the current guidelines and recommendations on this issue. RESULTS: Multiple discrepancies in the collection process have been identified, even in the products collected for the same company. Practical approach of satisfying all the requirements based on University of Nebraska Medical Center experience has been suggested. CONCLUSION: The current recommendations from multiple sources were reviewed in discussion.

Two acute psychiatric emergencies and prevalence of mental health disorders at an outpatient apheresis clinic: Implications for apheresis practitioners.

The prevalence of mental health disorders among apheresis patients is unknown. Patients with chronic conditions treated with apheresis in the outpatient setting often see their apheresis healthcare professionals more frequently than their referring physicians. In addition, many apheresis patients are on medications with psychiatric side effects such as steroids. Given the frequent interactions of apheresis practitioners with outpatients, psychiatric issues may be encountered. To highlight these issues, we report two psychiatric emergencies that occurred in an outpatient apheresis clinic. Additionally, the prevalence of mental health diagnoses in our outpatient clinic was determined to help estimate the exposure that apheresis teams have to patients with mental health diagnoses. Practical recommendations for apheresis practitioners when encountering psychiatric emergencies are summarized.

Therapeutic plasma exchange for steroid refractory idiopathic inflammatory myopathies with interstitial lung disease.

BACKGROUND: Idiopathic inflammatory myopathies (IIMs) encompass many rheumatologic diseases characterized by inflammatory muscle disease, typically unified by proximal muscle weakness. A subset of patients with IIM present with interstitial lung disease (ILD) with identifiable antibodies such as in anti-synthetase syndrome (AS) with antibodies to aminoacyl-tRNA synthetases, and clinically amyopathic dermatomyositis (CADM) with anti-melanoma differentiation-associated protein 5 (MDA5). Recent case reports demonstrate response to therapeutic plasma exchange (TPE) or column filtration plasmapheresis in IIM with ILD resistant to medical management. We present our experience with eight patients with IIM with ILD undergoing TPE at a large US-based hospital system. PATIENT CHARACTERISTICS: Eight patients with IIM with ILD were treated with TPE over the last 10 years. The therapy consisted of 5-7 one plasma volume exchanges every other day to daily. Seven of eight patients had identifiable antibodies. RESULTS: Following completion of TPE, seven of eight demonstrated improvement in pulmonary function despite lack of improvement of pulmonary function with standard therapy. CONCLUSION: In antibody-mediated, treatment refractory IIM with ILD, TPE may be a viable intervention. This is a disease for which the role of apheresis is evolving. CLINICAL TRIAL REGISTRATION: Not application.

Daratumumab interference in flow cytometric anti-granulocyte antibody testing can be overcome using non-human blocking antibodies.

BACKGROUND: Daratumumab (DARA), a human IgG1K monoclonal antibody targeting CD38, is used to treat refractory multiple myeloma patients. CD38 is expressed on many cell types (RBCs, granulocytes, lymphocytes, etc.), and thus, DARA can interfere with serological tests. Information regarding how DARA affects anti-granulocyte antibody (AGA) testing and optimal neutralization of DARA will help laboratories perform accurate testing. METHODS: Screening of AGA was performed by the granulocyte agglutination test (GAT) and the flow cytometric granulocyte immunofluorescence test (Flow-GIFT). Samples were tested from patients on DARA (n = 7), non-transfused blood donors (healthy controls, n = 7) and AGA reactive samples (positive controls, n = 5). Two neutralization experiments, CD38 removal with DTT and DARA epitope blockage with mouse anti-CD38, were evaluated. RESULTS: Positive reactivity of human IgG binding was observed in 5/7 DARA cases when tested by Flow-GIFT; however, all 7 cases had negative GAT agglutination results. Further studies by Flow-GIFT revealed DARA concentrations >0·63 µg/ml bound to granulocytes. DARA binding was negated by DTT though a reduced Flow-GIFT sensitivity was observed in positive control samples due to increased background detection of human IgG. Mouse anti-CD38 neutralized the detection of human IgG observed in DARA-treated patient serum without effecting controls. CONCLUSION: We established that DARA can interfere with AGA testing, leading to false positive Flow-GIFT results without causing GAT agglutination. DTT treatment increased background binding of secondary antibodies causing a decrease in Flow-GIFT sensitivity. In comparison, blockage of the DARA binding epitope using mouse anti-CD38 antibody was effective in neutralizing DARA interference while maintaining Flow-GIFT sensitivity.

Skin-resident murine dendritic cell subsets promote distinct and opposing antigen-specific T helper cell responses.

Skin-resident dendritic cells (DCs) are well positioned to encounter cutaneous pathogens and are required for the initiation of adaptive immune responses. There are at least three subsets of skin DC- Langerhans cells (LC), Langerin(+) dermal DCs (dDCs), and classic dDCs. Whether these subsets have distinct or redundant function in vivo is poorly understood. Using a Candida albicans skin infection model, we have shown that direct presentation of antigen by LC is necessary and sufficient for the generation of antigen-specific T helper-17 (Th17) cells but not for the generation of cytotoxic lymphocytes (CTLs). In contrast, Langerin(+) dDCs are required for the generation of antigen specific CTL and Th1 cells. Langerin(+) dDCs also inhibited the ability of LCs and classic DCs to promote Th17 cell responses. This work demonstrates that skin-resident DC subsets promote distinct and opposing antigen-specific responses.

Pheochromocytoma with Synchronous Ipsilateral Adrenal Cortical Adenoma.

BACKGROUND: Pheochromocytoma with synchronous ipsilateral adrenal cortical adenoma (PSCA) may present with mixed clinical, biochemical, and radiological features characteristic to each neoplasm subtype. METHODS: All patients with a pathological diagnosis of pheochromocytoma were evaluated for an ipsilateral cortical adenoma from 1994 through 2015. Retrospectively extracted data included indications for adrenalectomy, diagnostic workup (biochemical and radiographic), operative characteristics, pathological findings, and postoperative complications. RESULTS: Sixteen of 413 patients (4%) undergoing adrenalectomy for pheochromocytoma had a PSCA. Median patient age was 57.7 years (IQR 50.1, 63.1); 50% were male. On imaging, 75% of the adrenal neoplasms were found incidentally and only 50% were reported to have a synchronous ipsilateral neoplasm based on imaging findings. Clinically important cortical hormone secretion was diagnosed in 38% of these patients; 25% had glucocorticoid secretory autonomy; and 13% had primary aldosteronism. CONCLUSION: Physicians should be aware that adrenal neoplasms with mixed diagnostic findings may represent PSCA. Evaluation should be performed on this co-occurrence to prevent perioperative complications from resection of an unexpected secretory cortical neoplasm.

Environmental Contamination in Households of Patients with Recurrent Clostridium difficile Infection.

Recurrent Clostridium difficile infection (R-CDI) is common and difficult to treat, potentially necessitating fecal microbiota transplantation (FMT). Although C. difficilespores persist in the hospital environment and cause infection, little is known about their potential presence or importance in the household environment. Households of R-CDI subjects in the peri-FMT period and of geographically matched and age-matched controls were analyzed for the presence ofC. difficile Household environmental surfaces and fecal samples from humans and pets in the household were examined. Households of post-FMT subjects were also examined (environmental surfaces only). Participants were surveyed regarding their personal history and household cleaning habits. Species identity and molecular characteristics of presumptive C. difficile isolates from environmental and fecal samples were determined by using the Pro kit (Remel, USA), Gram staining, PCR, toxinotyping, tcdC gene sequencing, and pulsed-field gel electrophoresis (PFGE). Environmental cultures detected C. difficile on ≥1 surface in 8/8 (100%) peri-FMT households, versus 3/8 (38%) post-FMT households and 3/8 (38%) control households (P= 0.025). The most common C. difficile-positive sites were the vacuum (11/27; 41%), toilet (8/30; 27%), and bathroom sink (5/29; 17%).C. difficile was detected in 3/36 (8%) fecal samples (two R-CDI subjects and one household member). Nine (90%) of 10 households with multiple C. difficile-positive samples had a single genotype present each. In conclusion,C. difficile was found in the household environment of R-CDI patients, but whether it was found as a cause or consequence of R-CDI is unknown. If household contamination leads to R-CDI, effective decontamination may be protective.

Autocrine/paracrine TGF-ß1 inhibits Langerhans cell migration.

Langerhans cells (LCs) are skin-resident dendritic cells (DC) located in the epidermis that migrate to skin-draining lymph nodes during the steady state and in response to inflammatory stimuli. TGF-ß1 is a critical immune regulator that is highly expressed by LCs. The ability to test the functional importance of LC-derived TGF-ß1 is complicated by the requirement of TGF-ß1 for LC development and by the absence of LCs in mice with an LC-specific ablation of TGF-ß1 or its receptor. To overcome these problems, we have engineered transgenic huLangerin-CreER(T2) mice that allow for inducible LC-specific excision. Highly efficient and LC-specific expression was confirmed in mice bred onto a YFP Cre reporter strain. We next generated huLangerin-CreER(T2) × TGF-ßRII(fl) and huLangerin-CreER(T2) × TGF-ß1(fl) mice. Excision of the TGFßRII or TGFß1 genes induced mass migration of LCs to the regional lymph node. Expression of costimulatory markers and inflammatory cytokines was unaffected, consistent with homeostatic migration. In addition, levels of p-SMAD2/3 were decreased in LCs from wild-type mice before inflammation-induced migration. We conclude that TGF-ß1 acts directly on LCs in an autocrine/paracrine manner to inhibit steady-state and inflammation-induced migration. This is a readily targetable pathway with potential therapeutic implications for skin disease.

Microbiota transplantation restores normal fecal bile acid composition in recurrent Clostridium difficile infection.

Fecal microbiota transplantation (FMT) has emerged as a highly effective therapy for refractory, recurrent Clostridium difficile infection (CDI), which develops following antibiotic treatments. Intestinal microbiota play a critical role in the metabolism of bile acids in the colon, which in turn have major effects on the lifecycle of C. difficile bacteria. We hypothesized that fecal bile acid composition is altered in patients with recurrent CDI and that FMT results in its normalization. General metabolomics and targeted bile acid analyses were performed on fecal extracts from patients with recurrent CDI treated with FMT and their donors. In addition, 16S rRNA gene sequencing was used to determine the bacterial composition of pre- and post-FMT fecal samples. Taxonomic bacterial composition of fecal samples from FMT recipients showed rapid change and became similar to the donor after the procedure. Pre-FMT fecal samples contained high concentrations of primary bile acids and bile salts, while secondary bile acids were nearly undetectable. In contrast, post-FMT fecal samples contained mostly secondary bile acids, as did non-CDI donor samples. Therefore, our analysis showed that FMT resulted in normalization of fecal bacterial community structure and metabolic composition. Importantly, metabolism of bile salts and primary bile acids to secondary bile acids is disrupted in patients with recurrent CDI, and FMT corrects this abnormality. Since individual bile salts and bile acids have pro-germinant and inhibitory activities, the changes suggest that correction of bile acid metabolism is likely a major mechanism by which FMT results in a cure and prevents recurrence of CDI.

Early colon screening of adult patients with cystic fibrosis reveals high incidence of adenomatous colon polyps.

BACKGROUND AND GOALS: Cystic fibrosis (CF) is associated with increased incidence of gastrointestinal cancer. Increasing overall life expectancy of CF patients predicts emergence of colon cancer as a significant clinical problem in the adult CF population. The primary aim of this study was to estimate the incidence of adenomatous colon polyps in patients with CF during systematic screening by colonoscopy. STUDY: This is a single-center series of 45 CF patients aged 40 years and above (mean age, 47 y) undergoing colonoscopic screening. A fraction of these patients (9/45) had history of organ transplantation. Results from transplant and nontransplant patients were analyzed separately. RESULTS: Adult CF patients have a high incidence of adenomatous polyps identified by colonoscopy. In addition, positive examinations are characterized by multiple polyps and common features of advanced pathology. The incidence of adenomatous colon polyps is greater in male patients, although the 1 patient in this cohort found to have colorectal cancer was female. CONCLUSIONS: CF has features of a hereditary colon cancer syndrome. Increasing life expectancy of CF patients suggests that earlier colon screening in this population may be warranted. Optimal criteria for initiation of screening and frequency of surveillance should be subject of further studies.

Langerhans cells require MyD88-dependent signals for Candida albicans response but not for contact hypersensitivity or migration.

Langerhans cells (LC) are a subset of skin-resident dendritic cells (DC) that reside in the epidermis as immature DC, where they acquire Ag. A key step in the life cycle of LC is their activation into mature DC in response to various stimuli, including epicutaneous sensitization with hapten and skin infection with Candida albicans. Mature LC migrate to the skin-draining LN, where they present Ag to CD4 T cells and modulate the adaptive immune response. LC migration is thought to require the direct action of IL-1ß and IL-18 on LC. In addition, TLR ligands are present in C. albicans, and hapten sensitization produces endogenous TLR ligands. Both could contribute to LC activation. We generated Langerin-Cre MyD88(fl) mice in which LC are insensitive to IL-1 family members and most TLR ligands. LC migration in the steady state, after hapten sensitization and postinfection with C. albicans, was unaffected. Contact hypersensitivity in Langerin-Cre MyD88(fl) mice was similarly unaffected. Interestingly, in response to C. albicans infection, these mice displayed reduced proliferation of Ag-specific CD4 T cells and defective Th17 subset differentiation. Surface expression of costimulatory molecules was intact on LC, but expression of IL-1ß, IL-6, and IL-23 was reduced. Thus, sensitivity to MyD88-dependent signals is not required for LC migration, but is required for the full activation and function of LC in the setting of fungal infection.

Obstetric and Newborn Weak D-Phenotype RBC Testing and Rh Immune Globulin Management Recommendations: Lessons From a Blinded Specimen-Testing Survey of 81 Transfusion Services.

CONTEXT.­: Modern RHD genotyping can be used to determine when patients with serologic weak D phenotypes have RHD gene variants at risk for anti-D alloimmunization. However, serologic testing, RhD interpretations, and laboratory management of these patients are quite variable. OBJECTIVE.­: To obtain interlaboratory comparisons of serologic testing, RhD interpretations, Rh immune globulin (RhIG) management, fetomaternal hemorrhage testing, and RHD genotyping for weak D-reactive specimens. DESIGN.­: We devised an educational exercise in which 81 transfusion services supporting obstetrics performed tube-method RhD typing on 2 unknown red blood cell challenge specimens identified as (1) maternal and (2) newborn. Both specimens were from the same weak D-reactive donor. The exercise revealed how participants responded to these different clinical situations. RESULTS.­: Of reporting laboratories, 14% (11 of 80) obtained discrepant immediate-spin reactions on the 2 specimens. Nine different reporting terms were used to interpret weak D-reactive maternal RhD types to obstetricians. In laboratories obtaining negative maternal immediate-spin reactions, 28% (16 of 57) performed unwarranted antiglobulin testing, sometimes leading to recommendations against giving RhIG. To screen for excess fetomaternal hemorrhage after a weak D-reactive newborn, 47% (34 of 73) of reporting laboratories would have employed a contraindicated fetal rosette test, risking false-negative results and inadequate RhIG coverage. Sixty percent (44 of 73) of laboratories would obtain RHD genotyping in some or all cases. CONCLUSIONS.­: For obstetric and neonatal patients with serologic weak D phenotypes, we found several critical problems in transfusion service laboratory practices. We provide recommendations for appropriate testing, consistent immunohematologic terminology, and RHD genotype-guided management of Rh immune globulin therapy and RBC transfusions.

Acute ablation of Langerhans cells enhances skin immune responses.

Understanding the function of Langerhans cells (LCs) in vivo has been complicated by conflicting results from LC-deficient mice. Human Langerin-DTA mice constitutively lack LCs and develop exaggerated contact hypersensitivity (CHS) responses. Murine Langerin-diphtheria toxin receptor (DTR) mice allow for the inducible elimination of LCs and Langerin(+) dermal dendritic cells (dDCs) after administration of diphtheria toxin, which results in reduced CHS. When Langerin(+) dDCs have partially repopulated the skin but LCs are still absent, CHS returns to normal. Thus, LCs appear to be suppressive in human Langerin-DTA mice and redundant in murine Langerin-DTR mice. To determine whether inducible versus constitutive LC ablation explains these results, we engineered human Langerin-DTR mice in which diphtheria toxin ablates LCs without affecting Langerin(+) dDCs. The inducible ablation of LCs in human Langerin-DTR mice resulted in increased CHS. Thus, LC-mediated suppression does not require their absence during ontogeny or during the steady-state and is consistent with a model in which LCs actively suppress Ag-specific CHS responses.

Liquid Chromatography-Tandem Mass Spectrometry-Based α1-Antitrypsin (AAT) Testing.

OBJECTIVES: Failure to produce sufficient quantities of functional α1-antitrypsin (AAT) can result in AAT deficiency (AATD) and significant comorbidities. Laboratory testing plays a vital role in AATD, with diagnosis requiring documentation of both a low AAT level and a mutated allele. This retrospective evaluation examines the efficacy of a liquid chromatography-tandem mass spectrometry (LC-MS/MS) (proteotyping)-based algorithm for AATD detection. METHODS: A 16-month retrospective data analysis was performed on two cohorts: 5,474 samples tested with the proteotype-based algorithm and 16,147 samples directly tested by isoelectric focusing (IEF) phenotyping. RESULTS: LC-MS/MS reduced the rate of IEF testing by 97%. The 3% of cases reflexed to IEF resulted in 12 (0.2%) additional phenotype findings. Retrospectively applying the proteotype-based algorithm to the IEF cohort demonstrated a 99.9% sensitivity for the detection of deficiency-associated phenotypes. Most deficiency phenotypes missed by the proteotyping algorithm would come from heterozygous patients with an F, I, or P paired to an S or Z. In all of these cases, patient AAT levels were greater than 70 mg/dL, above the threshold for AAT augmentation therapy. CONCLUSIONS: The proteotype algorithm is a sensitive and cost-effective approach for the diagnosis of clinical AAT deficiency.

Cushing syndrome: uncovering Carney complex due to novel PRKAR1A mutation.

Carney complex (CNC) is a rare multiple neoplasia syndrome characterized by spotty pigmentation of the skin and mucosa in association with various non-endocrine and endocrine tumors, including primary pigmented nodular adrenocortical disease (PPNAD). A 20-year-old woman was referred for suspected Cushing syndrome. She had signs of cortisol excess as well as skin lentigines on physical examination. Biochemical investigation was suggestive of corticotropin (ACTH)-independent Cushing syndrome. Unenhanced computed tomography scan of the abdomen did not reveal an obvious adrenal mass. She subsequently underwent bilateral laparoscopic adrenalectomy, and histopathology was consistent with PPNAD. Genetic testing revealed a novel frameshift pathogenic variant c.488delC/p.Thr163MetfsX2 (ClinVar Variation ID: 424516) in the PRKAR1A gene, consistent with clinical suspicion for CNC. Evaluation for other clinical features of the complex was unrevealing. We present a case of PPNAD-associated Cushing syndrome leading to the diagnosis of CNC due to a novel PRKAR1A pathogenic variant. Learning points: PPNAD should be considered in the differential for ACTH-independent Cushing syndrome, especially when adrenal imaging appears normal. The diagnosis of PPNAD should prompt screening for CNC. CNC is a rare multiple neoplasia syndrome caused by inactivating pathogenic variants in the PRKAR1A gene. Timely diagnosis of CNC and careful surveillance can help prevent potentially fatal complications of the disease.

Radiologic-Pathologic Correlation: Acellular Dermal Matrix (Alloderm®) Used in Breast Reconstructive Surgery.

Acellular dermal matrix (ADM) such as Alloderm® is sometimes used in tissue reconstruction in primary and reconstructive breast surgeries. As ADM is incorporated into the native tissues, the evolving imaging findings that would correlate with varying degrees of host migration and neoangiogenesis into the matrix can be challenging to recognize. In the setting of a palpable or clinical area of concern after breast reconstructive surgery following breast cancer, confident diagnosis of a mass representing ADM rather than recurring or developing disease can be challenging. Such diagnostic imaging uncertainties generally result in short-term imaging and clinical follow-up, but occasionally, biopsy is performed for histopathological confirmation of benignity. A case of biopsy-proven Alloderm® is described. To the best of our knowledge, this is the first radiologic-pathologic correlation of ADM in the literature.

Stable engraftment of human microbiota into mice with a single oral gavage following antibiotic conditioning.

BACKGROUND: Human microbiota-associated (HMA) animal models relying on germ-free recipient mice are being used to study the relationship between intestinal microbiota and human disease. However, transfer of microbiota into germ-free animals also triggers global developmental changes in the recipient intestine, which can mask disease-specific attributes of the donor material. Therefore, a simple model of replacing microbiota into a developmentally mature intestinal environment remains highly desirable. RESULTS: Here we report on the development of a sequential, three-course antibiotic conditioning regimen that allows sustained engraftment of intestinal microorganisms following a single oral gavage with human donor microbiota. SourceTracker, a Bayesian, OTU-based algorithm, indicated that 59.3 ± 3.0% of the fecal bacterial communities in treated mice were attributable to the donor source. This overall degree of microbiota engraftment was similar in mice conditioned with antibiotics and germ-free mice. Limited surveys of systemic and mucosal immune sites did not show evidence of immune activation following introduction of human microbiota. CONCLUSIONS: The antibiotic treatment protocol described here followed by a single gavage of human microbiota may provide a useful, complimentary HMA model to that established in germ-free facilities. The model has the potential for further in-depth translational investigations of microbiota in a variety of human disease states.

Dynamic changes in short- and long-term bacterial composition following fecal microbiota transplantation for recurrent Clostridium difficile infection.

BACKGROUND: Fecal microbiota transplantation (FMT) is an effective treatment for recurrent Clostridium difficile infection (CDI) that often fails standard antibiotic therapy. Despite its widespread recent use, however, little is known about the stability of the fecal microbiota following FMT. RESULTS: Here we report on short- and long-term changes and provide kinetic visualization of fecal microbiota composition in patients with multiply recurrent CDI that were refractory to antibiotic therapy and treated using FMT. Fecal samples were collected from four patients before and up to 151 days after FMT, with daily collections until 28 days and weekly collections until 84 days post-FMT. The composition of fecal bacteria was characterized using high throughput 16S rRNA gene sequence analysis, compared to microbiota across body sites in the Human Microbiome Project (HMP) database, and visualized in a movie-like, kinetic format. FMT resulted in rapid normalization of bacterial fecal sample composition from a markedly dysbiotic state to one representative of normal fecal microbiota. While the microbiome appeared most similar to the donor implant material 1 day post-FMT, the composition diverged variably at later time points. The donor microbiota composition also varied over time. However, both post-FMT and donor samples remained within the larger cloud of fecal microbiota characterized as healthy by the HMP. CONCLUSIONS: Dynamic behavior is an intrinsic property of normal fecal microbiota and should be accounted for in comparing microbial communities among normal individuals and those with disease states. This also suggests that more frequent sample analyses are needed in order to properly assess success of FMT procedures.