Search

Early in 2020, the pandemic resulted in an enormous demand for personal protective equipment (PPE), which consists of face masks, face shields, respirators, and gowns. At our institution, at the request of hospital administration, the Lifespan 3D Printing Laboratory spearheaded an initiative to produce reusable N95 masks for use in the hospital setting. Through this article, we seek to detail our experience designing and 3D printing an N95 mask, highlighting the most important lessons learned throughout the process. Foremost among these, we were successful in producing a non-commercial N95 alternative mask which could be used in an era when N95 materials were extremely limited in supply. We identified five key lessons related to design software, 3D printed material airtightness, breathability and humidity dispersal, and ability for communication. By sharing our experience and the most valuable lessons we learned through this process, we hope to provide a helpful foundation for future 3D-printed N95 endeavors.

Background IgG4-related disease (IgG4-RD) is an immune-mediated disease that may present as a tumefactive lesion in nearly any organ. These mass lesions often resemble malignancy both clinically and radiologically, and some patients undergo surgical resection which could possibly be avoided with early recognition of IgG4-RD. We performed a retrospective single-center study examining how many patients with IgG4-RD were initially believed to have malignancy, with particular attention to those who underwent potentially avoidable surgical procedures. Methods Sixty-three patients with biopsy confirmed IgG4-related disease were included. Clinical, laboratory, radiological, and histological data were collected and analyzed. Results Over 60% of patients (38/63) were initially thought to have a malignancy when they initially presented with symptomatic IgG4-RD. The most common types of malignancy suspected were lymphoma (18/38) and pancreatic cancer (11/38). Of the 38 patients with suspected malignancy, 14 underwent an invasive intervention either to alleviate the severity of their symptoms or as treatment for their presumed malignancy. These included Whipple resection/attempted Whipple (3), nephrectomy (3), bile duct resection and reconstruction (1), removal of other abdominal/retroperitoneal masses (3), and stenting of obstructed organs (4). Conclusion IgG4-RD should be on the differential diagnosis of patients with mass lesions, in particular those with pancreatic masses and obstructive jaundice, extensive lymphadenopathy, or retroperitoneal masses. Oncologists and other physicians involved in cancer care should be aware of the various manifestations and diagnostic approach to IgG4-RD in order to provide accurate diagnosis and minimize unnecessary invasive procedures. While some procedures in this study, such as stenting of obstructed organs, were required regardless of diagnosis, others could have potentially been avoided or attenuated with early recognition of IgG4-RD. Patients with mass lesions suspicious for IgG4-RD should have serum protein electrophoresis, IgG subclass measurement, and, where possible, tissue biopsy before undergoing major surgical resection. Consultation with a physician experienced in IgG4-RD is recommended.

Objectives We present a full autopsy with a focused radiology and pathologic review of the coronary arteries. We hope that the results described in this article will help create better diagnostic measures and prevent future coronary artery vasculitis misdiagnosis. Methods A full autopsy was performed on the body of Dr Myung Choong Yoon, with full consent from the family, within the department of pathology and laboratory medicine at Vancouver General Hospital. Tissue samples from the heart, brain, lungs, and spinal cord were submitted to specialist pathologists for histologic processing. Results Cardiac gated computed tomography coronary angiography suggested periarteritis. Coexistent calcified coronary atherosclerosis with linear calcifications was present along the luminal wall, along with coronary artery ectasia. Histologic assessment confirmed features of dense adventitial fibrosis around the coronary arteries, with an exuberant lymphoplasmacytic infiltrate and numerous plasma cells consistent with IgG4-related disease. The media of the coronary arteries was markedly attenuated or completely absent, which likely contributed to the coronary arterial ectasia noted microscopically. These findings confirmed IgG4-related coronary arteritis. Conclusions Coronary periarteritis is an uncommon manifestation of IgG4-related disease established radiographically and later by autopsy.

Chromosomal expression of heterologous genes offers stability and maintenance advantages over episomal expression, yet remains difficult to optimize through site-specific integration. The challenge has in large part been due to the variability of chromosomal gene expression, which has only recently been shown to be affected by multiple factors, including the local genomic context. In this work we utilize Tn5 transposase to randomly integrate a three-gene csc operon encoding nonphosphotransferase sucrose catabolism into the E. coli K-12 chromosome. Isolates from the transposon library yielded a range of growth rates on sucrose as the sole carbon source, including some that were comparable to that of E. coli K-12 on glucose (μmax = 0.70 ± 0.03 h-1). Narrowness of the growth rate distributions and faster growth compared to plasmids indicate that efficient csc expression is attainable. Furthermore, enhanced growth rate upon transduction into strains that underwent adaptive laboratory evolution indicate that sucrose catabolism is not limiting to cellular growth. We also show that transduction of a csc fast-growth locus into an isobutanol production strain yields high titer (7.56 ± 0.25 g/L) on sucrose as the sole carbon source. Our results demonstrate that random integration is an effective strategy for optimizing heterologous expression within the context of cellular metabolism for both fast growth and biochemical production phenotypes.

Background Hypereosinophilia (HE, persistent peripheral blood eosinophilia > 1.5 × 109 /L) and hypereosinophilic syndrome (HES, HE with end-organ damage) are classified as primary (due to a myeloid clone), secondary (due to a wide variety of reactive causes), or idiopathic. Diagnostic evaluation of eosinophilia is challenging, in part because secondary causes of HE/HES such as lymphocyte-variant HES (L-HES) and vasculitis are difficult to diagnose, and emerging causes such as immunoglobulin G4-related disease (IgG4-RD) have rarely been examined. Objective and methods We reviewed 100 consecutive patients with HE/HES who underwent extensive evaluation for primary and secondary eosinophilia at a single tertiary care center to determine causes of HE/HES in a modern context. Results Six patients had primary HE/HES, 80 had a discrete secondary cause identified, and 14 had idiopathic HE/HES. The most common causes of secondary eosinophilia were L-HES/HES of unknown significance (L-HESus) (20), IgG4-RD (9), and eosinophilic granulomatosis with polyangiitis (EGPA) (8). Conclusions In contrast to other large published series of HE/HES, most patients in this study were found to have a discrete secondary cause of eosinophilia and only 14 were deemed idiopathic. These findings highlight the importance of extensive evaluation for secondary causes of eosinophilia such as L-HES, IgG4-RD, and EGPA.

Background: Serum IgG4 is typically measured to investigate for Immunoglobulin G4-related Disease (IgG4-RD), a fibroinflammatory condition associated with polyclonal increase in serum IgG4. However, increased IgG4 can also be monoclonal, and little is known about IgG4 myeloma. Methods: We describe two cases of IgG4 myeloma without clinical, radiologic, or laboratory features of IgG4-related disease. Results: An 84 year old man presented with anemia and compression fractures and a 77 year old man presented with anemia, hypercalcemia and renal failure. Both had markedly elevated monoclonal serum IgG4, 34 g/L and 48 g/L in the beta region, and increased IgG positive bone marrow plasma cells, 50% and 80%, respectively. Neither had clinical or radiological manifestations of IgG4-related disease (IgG4-RD) such as salivary or lacrimal gland swelling, autoimmune pancreatitis , or retroperitoneal fibrosis. Both cases responded well to standard myeloma therapy. The IgG4 paraprotein caused spuriously elevated beta-2 microglobulin of 45.2 mg/L in case two due to interference with the assay. Conclusion: These cases illustrate the importance of performing serum protein electrophoresis in tandem with IgG subclasses to distinguish between polyclonal and monoclonal increases in serum IgG4. The lack of typical IgG4-RD features in these two patients suggests that monoclonal elevation in serum IgG4 alone is insufficient to cause the organ damage characteristic of IgG4-RD. Larger studies of IgG myeloma subtypes are warranted to explore whether IgG1, IgG2, IgG3 and IgG4 myeloma differ in natural history and whether the interference with beta-2 microglobulin is specific to IgG4 monoclonal proteins.

Isoprenoid compounds are biologically ubiquitous, and their characteristic modularity has afforded products ranging from pharmaceuticals to biofuels. Isoprenoid production has been largely successful in Escherichia coli and Saccharomyces cerevisiae with metabolic engineering of the mevalonate (MVA) and methylerythritol phosphate (MEP) pathways coupled with the expression of heterologous terpene synthases. Yet conventional microbial chassis pose several major obstacles to successful commercialization including the affordability of sugar substrates at scale, precursor flux limitations, and intermediate feedback-inhibition. Now, recent studies have challenged typical isoprenoid paradigms by expanding the boundaries of terpene biosynthesis and using non-model organisms including those capable of metabolizing atypical C1 substrates. Conversely, investigations of non-model organisms have historically informed optimization in conventional microbes by tuning heterologous gene expression. Here, we review advances in isoprenoid biosynthesis with specific focus on the synergy between model and non-model organisms that may elevate the commercial viability of isoprenoid platforms by addressing the dichotomy between high titer production and inexpensive substrates.

Isoprenoid compounds are biologically ubiquitous, and their characteristic modularity has afforded products ranging from pharmaceuticals to biofuels. Isoprenoid production has been largely successful in Escherichia coli and Saccharomyces cerevisiae with metabolic engineering of the mevalonate (MVA) and methylerythritol phosphate (MEP) pathways coupled with the expression of heterologous terpene synthases. Yet conventional microbial chassis pose several major obstacles to successful commercialization including the affordability of sugar substrates at scale, precursor flux limitations, and intermediate feedback-inhibition. Now, recent studies have challenged typical isoprenoid paradigms by expanding the boundaries of terpene biosynthesis and using non-model organisms including those capable of metabolizing atypical C1 substrates. Conversely, investigations of non-model organisms have historically informed optimization in conventional microbes by tuning heterologous gene expression. Here, we review advances in isoprenoid biosynthesis with specific focus on the synergy between model and non-model organisms that may elevate the commercial viability of isoprenoid platforms by addressing the dichotomy between high titer production and inexpensive substrates.

Background The usage of immunosuppressive medications (ISMs), and specifically disease modifying anti-rheumatic drugs (DMARDs), in a wide range of internal medicine subspecialties has increased the risk of hepatitis B virus re-activation (HBVr). We assessed the understanding of HBVr using a Canada-wide survey. Methods An electronic survey was sent to 521 members of the Canadian Rheumatology Association (CRA). The questions focused on the knowledge of screening, monitoring and management of patients with chronic or past infection with HBV in the setting of starting ISMs.The results were compared to the American Gastroenterology Association (AGA) guidelines. Results A total of142 respondents were included in the analysis (response rate = 27.3%). Over 50% of the respondents would order unnecessary tests such as anti-HBs or anti-HBc for monitoring a HBsAg positive patient on an ISMs. There were 43% of responders who answered incorrectly to starting anti-viral prophylaxis for HBsAg positive patients on synthetic DMARDs (sDMARDs). Conclusion There are some knowledge gaps amongst physicians managing rheumatology patients with chronic or past infection with HBV in the setting of ISMs. The AGA guidelines were summarized and incorporated into a user-friendly guide.

Pathway gene expression from the chromosome is optimized by a method of random site integrations and high-throughput screening., Chromosomal integration of recombinant genes is desirable compared with expression from plasmids due to increased stability, reduced cell-to-cell variability, and elimination of the need for antibiotics for plasmid maintenance. Here, we present a new approach for tuning pathway gene expression levels via random integration and high-throughput screening. We demonstrate multiplexed gene integration and expression-level optimization for isobutanol production in Escherichia coli. The integrated strains could, with far lower expression levels than plasmid-based expression, produce high titers (10.0 ± 0.9 g/liter isobutanol in 48 hours) and yields (69% of the theoretical maximum). Close examination of pathway expression in the top-performing, as well as other isolates, reveals the complexity of cellular metabolism and regulation, underscoring the need for precise optimization while integrating pathway genes into the chromosome. We expect this method for pathway integration and optimization can be readily extended to a wide range of pathways and chassis to create robust and efficient production strains.

This article will review the structure and function of IgG4, methods of measuring serum IgG4 concentrations, clinical conditions associated with increased and decreased serum IgG4, and the test characteristics of serum IgG4 in the diagnosis and management of Immunoglobulin G4-Related Disease (IgG4-RD). The four subclasses of IgG were discovered in 1964 through experiments on monoclonal IgG in patients with myeloma. Since 2001, interest in measuring serum IgG subclasses has increased dramatically due to the emergence of IgG4-RD, a multisystem fibroinflammatory condition wherein polyclonal serum IgG4 concentration is increased in approximately 70% of cases. Increased serum IgG4 typically manifests as a restriction in the anodal gamma region on serum protein electrophoresis, often with beta-gamma bridging, and can be mistaken as a monoclonal protein or polyclonal increase in IgA. Limitations of current clinical methods used in quantitation of serum IgG4 concentrations will be discussed, including the common immunonephelometric assays and LC-MS/MS based assays. Polyclonal IgG4 elevation is not specific for IgG4-RD, and may also occur in conditions such as eosinophilic granulomatosis with polyangiitis (EGPA), lymphoma, and multicentric Castleman disease (MCD). Race and gender differences also affect interpretation of serum IgG4 concentrations, for instance Asians have a higher serum IgG4 concentration than Whites and males have a higher concentration than females.

Background Retroperitoneal fibrosis (RPF) is characterized by the proliferation of fibrous tissue in the retroperitoneum. The majority of RPF cases are due to idiopathic or IgG4-related disease. Recent studies on IgG4-related disease have shown rituximab to be an effective treatment. The current first-line treatment for idiopathic RPF (iRPF) is glucocorticoid therapy. Relapse rates vary widely in the literature, and DMARDs remain poorly studied. We sought to evaluate the efficacy of rituximab in idiopathic RPF by quantifying changes in iRPF diameter on imaging pre- and post-rituximab therapy and response by lab parameters in 10 iRPF patients. Methods We selected 10 patients diagnosed with iRPF and previously treated with rituximab (1000 mg) in two doses approximately 2 weeks apart. Pre- and post-therapy contrast enhanced cross-sectional abdomen and pelvis imaging were compared. In all patients, the thickest portion of the peri-aortic disease was measured in the axial and coronal planes. The presence of acute or long standing back pressure related renal findings were documented. Details of clinical visits including patient demographics and laboratory evaluations were collected pre- and post-therapy. Statistical analysis was performed using a Wilcoxon signed rank test. Results The RPF diameter around the aorta before and after therapy decreased from a mean of 15.9 ± 4.9 mm to 10.6 ± 6.1 mm, respectively (p p = 0.02). Conclusion A comparison of pre and post-rituximab imaging studies revealed a statistically significant decrease in iRPF diameter following treatment with rituximab.

Background IgG4-related disease (IgG4-RD) is a recently recognized condition defined by characteristic histopathologic findings in affected organs. Serum IgG4 concentration is often but not always elevated. The sensitivity and specificity of serum IgG4 vary greatly across studies and has been anecdotally associated to ethnicity. Our study was conducted to investigate the difference in serum IgG4 levels between Asian and non-Asian patients with IgG4-RD. Methods This is a single-center retrospective study of 26 Asian and 10 non-Asian patients with histologically confirmed IgG4-RD. Serum IgG4 levels, clinical features and other laboratory findings were compared between the 2 groups, 31 Asian and 11 non-Asian patients with non-IgG4-RD rheumatic diseases were randomly identified to evaluate test characteristics of serum IgG4 measurement. Results Median serum IgG4 at time of diagnosis was significantly higher in Asian (median = 11.2 g/L, interquartile range: 4.6-19.7) than non-Asian patients (median = 2.9 g/L, interquartile range: 0.7-5.4, P = 0.0094), as well as the median serum IgG and total protein. Asian patients had more eosinophilia and polyclonal hypergammaglobulinemia than non-Asian patients ( P = 0.016 and 0.001, respectively). Test sensitivity was higher in Asian (96%) than non-Asian patients (67%), whereas test specificity was higher in non-Asian patients (91% versus 71%). Conclusion Asian patients with IgG4-RD have more exuberant serum IgG4, IgG and polyclonal hypergammaglobulinemia than non-Asian patients; the mechanism of this difference requires further study. These findings have significant clinical importance and must be accounted for in the diagnostic workup of patients in multiethnic settings.

Objective To evaluate whether corpus callosum (CC) lesions are inextricably linked to CNS symptoms of Susac Syndrome (SuS) by reviewing published cases to find instances where: 1) CC lesions occur without CNS symptoms, and 2) whether patients with CNS symptoms lack CC lesions. Methods 100 reported cases of SuS were identified in PubMed. Clinical symptoms, para-clinical testing and MRI data were collected both at presentation and for any available follow-up and analyzed. Cases were reviewed to evaluate how they met European diagnostic criteria for SuS (EuSaC) both at first presentation and at most recent evaluation after followup, if available. Results Limited disease is a common finding in the 100 recently published cases and 56/100 cases did not meet EuSaC probable or definite criteria at first evaluation. CC lesions were not inextricably linked with encephalopathy, as 8 cases presented with CC lesions without CNS symptoms and 6 cases had encephalopathy without CC lesions. In five patients with both eye and ear involvement, isolated CC lesions or CNS symptoms could enhance diagnostic certainty. This may reduce specificity, but would increase sensitivity, ultimately benefitting patient care. Conclusion Patients with early SuS rarely meet diagnostic criteria at presentation. Future diagnostic criteria could make use of unlinked CC lesions or CNS symptoms.

OBJECTIVE To compare the clinical and laboratory features of IgG4-related disease (IgG4-RD) and lymphocyte-variant hypereosinophilic syndrome (L-HES), two rare diseases that often present with lymphadenopathy, gastrointestinal symptoms, eosinophilia, and elevated immunoglobulins/IgE. METHOD Comparative case series of 31 patients with IgG4-RD and 13 patients with L-HES. RESULTS Peripheral blood eosinophilia was present in eight of 31 patients with IgG4-RD compared to 13 of 13 patients with L-HES (median eosinophils 0.4 vs 7.0 giga/L, P=.001) and 12 of 20 patients with IgG4-RD had increased serum IgE compared to eight of 13 patients with L-HES, P=.930. Twenty-seven of 30 patients with IgG4-RD had elevated serum IgG4 compared to five of 12 patients with L-HES (median IgG4 9.6 g/L vs 0.80 g/L, P=.002). Flow cytometry demonstrated an aberrant T-cell phenotype in 7 of 23 patients with IgG4-RD and 13 of 13 patients with L-HES (P

Key Clinical Message Lymphangiomas are benign tumors of the lymphatic vessels, which can be inflammatory and occasionally steroid‐responsive. IgG4‐related disease (IgG4‐RD) is a recently defined fibro‐inflammatory condition. We describe a novel association between reactive IgG4+ plasma cells and cystic lymphangioma in a young woman who had a dramatic clinical response to steroids.

Immunoglobulin G4-related disease (IgG4-RD) is a chronic mass-forming inflammatory disease characterized by fibroblastic proliferation and mixed inflammatory cell infiltration. IgG4-RD can involve one or multiple organs, and the most commonly affected organs include the pancreas, salivary glands, and the orbit. We present a case of a 66-year-old man, with a history of sarcoidosis, who presented with an obstructing ileocecal mass highly suspicious for malignancy. After surgical resection and pathological and serological evaluation, a diagnosis of IgG4-RD was rendered. In the absence of other manifestations, preoperative diagnosis is challenging, and IgG4-RD may continue to be a diagnostic pitfall.

Algal biofuel has yet to realize its potential as a commercial and sustainable bioenergy source, largely due to the challenge of maximizing and sustaining biomass production with respect to energetic and material inputs in large-scale cultivation. Experimental studies have shown that multispecies algal polycultures can be designed to enhance biomass production, stability, and nutrient recycling compared to monocultures. Yet, it remains unclear whether these impacts of biodiversity make polycultures more sustainable than monocultures. Here, we present results of a comparative life cycle assessment (LCA) for algal biorefineries to compare the sustainability metrics of monocultures and polycultures of six fresh-water algal species. Our results showed that when algae were grown in outdoor experimental ponds, certain bicultures improved the energy return on investment (EROI) and greenhouse gas emissions (GHGs) by 20% and 16%, respectively, compared to the best monoculture. Bicultures outperformed monocultures by performing multiple functions simultaneously (e.g., improved stability, nutrient efficiency, biocrude characteristics), which outweighed the higher productivity attainable by a monoculture. Our results demonstrate that algal polycultures with optimized multifunctionality lead to enhanced life cycle metrics, highlighting the significant potential of ecological engineering for enabling future environmentally sustainable algal biorefineries.

Background IgG 4 -related disease (IgG 4 -RD) is a systemic condition of unknown cause characterized by highly fibrotic lesions with dense lymphoplasmacytic infiltrates. CD4 + T cells constitute the major inflammatory cell population in IgG 4 -RD lesions. Objective We used an unbiased approach to characterize CD4 + T-cell subsets in patients with IgG 4 -RD based on their clonal expansion and ability to infiltrate affected tissue sites. Methods We used flow cytometry to identify CD4 + effector/memory T cells in a cohort of 101 patients with IgG 4 -RD. These expanded cells were characterized by means of gene expression analysis and flow cytometry. Next-generation sequencing of the T-cell receptor β chain gene was performed on CD4 + SLAMF7 + cytotoxic T lymphocytes (CTLs) and CD4 + GATA3 + T H 2 cells in a subset of patients to identify their clonality. Tissue infiltration by specific T cells was examined by using quantitative multicolor imaging. Results CD4 + effector/memory T cells with a cytolytic phenotype were expanded in patients with IgG 4 -RD. Next-generation sequencing revealed prominent clonal expansions of these CD4 + CTLs but not CD4 + GATA3 + memory T H 2 cells in patients with IgG 4 -RD. The dominant T cells infiltrating a range of inflamed IgG 4 -RD tissue sites were clonally expanded CD4 + CTLs that expressed SLAMF7, granzyme A, IL-1β, and TGF-β1. Clinical remission induced by rituximab-mediated B-cell depletion was associated with a reduction in numbers of disease-associated CD4 + CTLs. Conclusions IgG 4 -RD is prominently linked to clonally expanded IL-1β– and TGF-β1–secreting CD4 + CTLs in both peripheral blood and inflammatory tissue lesions. These active, terminally differentiated, cytokine-secreting effector CD4 + T cells are now linked to a human disease characterized by chronic inflammation and fibrosis.

Algae have enormous potential as bio-factories for the efficient production of a wide array of high-value products, and eventually as a source of renewable biofuels. However, tools for engineering the nuclear genomes of algae remain scarce and limited in functionality. In this study, synthetic algal promoters (saps) were generated as a tool for increasing nuclear gene expression and as a model for understanding promoter elements and structure in green algae. Promoters were generated to mimic native cis-motif elements, structure, and overall nucleotide composition of top expressing genes from Chlamydomonas reinhardtii. Twenty five saps were used to drive expression of a fluorescent reporter in transgenic algae. A majority of the promoters were functional in vivo and seven were identified to drive expression of the fluorescent reporter better than the current best endogenous promoter in C. reinhardtii, the chimeric hsp70/rbs2 promoter. Further analysis of the best synthetic promoter, sap11, revealed a new DNA motif essential for promoter function that is widespread and highly conserved in C. reinhardtii. These data demonstrate the utility of synthetic promoters to drive gene expression in green algae, and lays the groundwork for the development of a suite of saps capable of driving the robust and complex gene expression that will be required for algae to reach their potential as an industrial platform for photosynthetic bio-manufacturing.

IgG4-related disease is a fibro-inflammatory condition that can affect nearly any organ system. Common presentations include major salivary and lacrimal gland enlargement, orbital disease, autoimmune pancreatitis, retroperitoneal fibrosis and tubulointerstitial nephritis. This review focuses on the hematologic manifestations of IgG4-related disease, including lymphadenopathy, eosinophilia, and polyclonal hypergammaglobulinemia. The disease can easily be missed by unsuspecting hematologists, as patients may present with clinical problems that mimic disorders such as multicentric Castleman disease, lymphoma, plasma cell neoplasms and hypereosinophilic syndromes. When IgG4-related disease is suspected, serum protein electrophoresis and IgG subclasses are helpful as initial tests but a firm histological diagnosis is essential both to confirm the diagnosis and to rule out mimickers. The central histopathological features are a dense, polyclonal, lymphoplasmacytic infiltrate enriched with IgG4-positive plasma cells (with an IgG4/IgG ratio >40%), storiform fibrosis, and obliterative phlebitis. Importantly for hematologists, the latter two features are seen in all tissues except bone marrow and lymph nodes, making these two sites suboptimal for histological confirmation. Many patients follow an indolent course and respond well to treatment, but a significant proportion may have highly morbid or fatal complications such as periaortitis, severe retroperitoneal fibrosis or pachymeningitis. Corticosteroids are effective but cause new or worsening diabetes in about 40% of patients. Initial response rates to rituximab are high but durable remissions are rare. More intensive lymphoma chemotherapy regimens may be required in rare cases of severe, refractory disease, and targeted therapy against plasmablasts, IgE and other disease biomarkers warrant further exploration.

A. Khosroshahi, Z. S. Wallace, J. L. Crowe, T. Akamizu, A. Azumi, M. N. Carruthers, S. T. Chari, E. Della-Torre, L. Frulloni, H. Goto, P. A. Hart, T. Kamisawa, S. Kawa, M. Kawano, M. H. Kim, Y. Kodama, K. Kubota, M. M. Lerch, M. L€ ohr, Y. Masaki, S. Matsui, T. Mimori, S. Nakamura, T. Nakazawa, H. Ohara, K. Okazaki, J. H. Ryu, T. Saeki, N. Schleinitz, A. Shimatsu, T. Shimosegawa, H. Takahashi, M. Takahira, A. Tanaka, M. Topazian, H. Umehara, G. J. Webster, T. E. Witzig, M. Yamamoto, W. Zhang, T. Chiba, and J. H. Stone

This study aimed to compare expectations and experiences of fellows to those of faculty in vascular surgery fellowship programs with regard to endovascular training. Anonymous surveys were sent to fellows (n = 235) and program directors (n = 147), with 79 fellows and 65 faculty members responding. Fellows noted higher expectations of their endovascular skills prior to starting fellowship than the faculty group reported expecting. Faculty assessed fellows' pre-training endovascular skills at a significantly lower level than the fellows' self-assessment. Fellows were significantly less satisfied with the structured aspects of endovascular training than the faculty believed them to be. Only 3% of fellows vs. 32% of faculty felt that the presence of an endovascular simulator affected how residents ranked fellowship programs during the match. In conclusion, incoming fellows in vascular surgery fellowship programs have high expectations of themselves, but may overestimate their actual pre-training endovascular skills. Fellows desire more structured endovascular training, which is not recognized by faculty. Endovascular simulators are valued, but may not be a significant draw in the match process.

ObjectivesTo evaluate the efficacy of rituximab (RTX) in IgG4-related disease (IgG4-RD) in an open-label pilot trial.MethodsWe treated 30 IgG4-RD patients with two doses of RTX (1000 mg each). The participants were either treated with RTX alone (n = 26; 87%) or required to discontinue baseline glucocorticoids (GC) within 2 months (n = 4; 13%). Disease activity was measured by the IgG4-RD Responder Index (IgG4-RD RI) and physician's global assessment (PGA). Disease response was defined as the improvement of the IgG4-RD RI by two points. The primary outcome, measured at 6 months, was defined as: (1) decline of the IgG4-RD RI ≥2 points compared with baseline; (2) no disease flares before month 6; and (3) no GC use between months 2 and 6. Complete remission was defined as an IgG4-RD RI score of 0 with no GC use.ResultsDisease responses occurred in 97% of participants. The baseline IgG4-RD RI and PGA values, 11±7 and 63±22 mm, respectively, declined to 1±2 and 11±16 mm at 6 months (both pConclusionsRTX appears to be an effective treatment for IgG4-RD, even without concomitant GC therapy.Trial registration numberClinicalTrials.gov identifier: NCT01584388.

BACKGROUND The Binding Site immunonephelometric (IN) IgG subclass reagents (IgG1, IgG2, IgG3, IgG, BSIN) are used for assessment of both immunodeficiency and IgG4-related disease (IgG4-RD). In our laboratory, suspected analytic errors were noted in patients with increases in IgG4: The sum of the individual IgG subclasses was substantially greater than the measured total IgG concentrations (unlike samples with normal IgG4), and the IgG4 concentration was always less than the IgG2 concentration. METHODS We developed a tryptic digest LC-MS/MS method to quantify IgG1, IgG2, IgG3, and IgG4 in serum. Samples with IgG4 concentrations ranging from RESULTS Multivariate linear regression identified 3 subclass tests with multiple predictors of the measured subclass concentration. For these 3 subclasses, the predominant predictors were (in terms of LC-MS/MS IgG subclass measurement coefficients) BSIN IgG1 = 0.89·IgG1 + 0.4·IgG4; BSIN IgG2 = 0.94·IgG4 + 0.89·IgG2; and SIN IgG2 = 0.72·IgG2 + 0.24·IgG4. CONCLUSIONS There is apparent IgG4 cross-reactivity with select IN subclass measurements affecting tests from both vendors tested. These findings can be explained either by direct cross-reactivity of the IN reagents with the IgG4 subclass or unique physicochemical properties of IgG4 that permit nonspecific binding of IgG4 heavy chain to other IgG immunoglobulin heavy chains. Irrespective of the mechanism, the observed intermethod discrepancies support the use of LC-MS/MS as the preferred method for measurement of IgG subclasses when testing patients with suspected IgG4-RD.

Algae are ubiquitous in natural ecosystems and have been studied extensively for biofuel production due to their unique metabolic capabilities. Most studies to date have approached biofuel optimization through synthetic biology and process engineering with few industrial scale projects considering algal community interactions. Such interactions can potentially lead to increased productivity and reduced community invasability, both important characteristics for scalable algal biofuel production. It is estimated that over a million species of algae exist such that elucidating the interactions that might be beneficial for biofuel production remains extremely resource and time intensive. Here we describe a strategy for rapid, high-throughput screening of algal community combinations using a microfluidic platform to generate millions of parallel, nanoliter-scale algal mixed cultures for estimation of biomass accumulation. Model communities were first studied in a bench scale flask experiment and then examined using microfluidic droplets. These experiments showed consistent results for both positively interacting algal bicultures that increase biomass when together, and negatively interacting bicultures that decrease biomass. Specifically, these included enhanced performance of two bicultures, Ankistrodesmus falcatus and Chlorella sorokiniana, Chlorella sorokiniana and Selenastrum minutum, and reduced performance of a biculture consisting of Selenastrum capricornutum and Scenedesmus ecornis. While the ultimate techno-economic feasibility of algal bioproducts hinges on an amalgamation of scientific fields, rapid screening of algal communities will prove imperative for efficiently discovering community interactions.

Immunoglobulin-4 (IgG4-) related disease is a newly described treatable condition that has recently expanded the differential diagnosis of inflammatory meningeal disorders. This review will discuss the main clinical and pathophysiological features of IgG4-related meningeal disease in the context of meningeal inflammatory disorders in general. Particular attention will be dedicated to the differential diagnosis and the different therapeutic approaches.

Background IgG 4 -related disease (IgG 4 -RD) is a poorly understood, multiorgan, chronic inflammatory disease characterized by tumefactive lesions, storiform fibrosis, obliterative phlebitis, and accumulation of IgG 4 -expressing plasma cells at disease sites. Objective The role of B cells and IgG 4 antibodies in IgG 4 -RD pathogenesis is not well defined. We evaluated patients with IgG 4 -RD for activated B cells in both disease lesions and peripheral blood and investigated their role in disease pathogenesis. Methods B-cell populations from the peripheral blood of 84 patients with active IgG 4 -RD were analyzed by using flow cytometry. The repertoire of B-cell populations was analyzed in a subset of patients by using next-generation sequencing. Fourteen of these patients were longitudinally followed for 9 to 15 months after rituximab therapy. Results Numbers of CD19 + CD27 + CD20 − CD38 hi plasmablasts, which are largely IgG4 + , are increased in patients with active IgG 4 -RD. These expanded plasmablasts are oligoclonal and exhibit extensive somatic hypermutation, and their numbers decrease after rituximab-mediated B-cell depletion therapy; this loss correlates with disease remission. A subset of patients relapse after rituximab therapy, and circulating plasmablasts that re-emerge in these subjects are clonally distinct and exhibit enhanced somatic hypermutation. Cloning and expression of immunoglobulin heavy and light chain genes from expanded plasmablasts at the peak of disease reveals that disease-associated IgG 4 antibodies are self-reactive. Conclusions Clonally expanded CD19 + CD27 + CD20 − CD38 hi plasmablasts are a hallmark of active IgG 4 -RD. Enhanced somatic mutation in activated B cells and plasmablasts and emergence of distinct plasmablast clones on relapse indicate that the disease pathogenesis is linked to de novo recruitment of naive B cells into T cell–dependent responses by CD4 + T cells, likely driving a self-reactive disease process.

ObjectivesWe evaluated the sensitivity, specificity and positive and negative predictive values of elevated serum IgG4 concentrations for the diagnosis of IgG4-RD.MethodsBetween 2001 and 2011, 190 unique patients had elevated serum IgG4 measurements. We reviewed electronic medical records to determine the indication for IgG4 measurement and underlying clinical diagnosis. Additionally, we reviewed the records of 190 other randomly selected patients from a pool of 3360 with normal results, to evaluate test characteristics of the IgG4 measurement.ResultsAmong 380 patients analysed, 72 had either probable or definite IgG4-RD. Sixty-five of the 72 IgG4-RD patients had elevated serum IgG4 concentrations (mean: 405 mg/dL; range 140–2000 mg/dL), for a sensitivity of 90%. Among the 308 subjects without IgG4-RD, 125 had elevated IgG4 (mean: 234 mg/dL; range 135–1180 mg/dL) and 183 had normal IgG4 concentrations, for a specificity of 60%. The negative predictive value of a serum IgG4 assay was 96%, but the positive predictive value only 34%. Analysis of the serum IgG4/total IgG ratio did not improve these test characteristics. Doubling the cutoff for IgG4 improved specificity (91%) but decreased sensitivity to 35%.DiscussionMultiple non-IgG4-RD conditions are associated with elevated serum IgG4, leading to poor specificity and low positive predictive value for this test. A substantial subset of patients with biopsy-proven IgG4-RD do not have elevated serum IgG4. Neither doubling the cutoff for serum IgG4 nor examining the serum IgG4/IgG ratio improves the overall test characteristics for the diagnosis of IgG4-RD.

We present an atypical presentation of Rosai-Dorfman disease (RDD). Due to its overlap with IgG4-related disease (IgG4-RD), this case proved to be a diagnostic dilemma. Our case is an example of the importance of having a broad-based differential and, ultimately, an in-depth histopathological review. Our patient presented with a constellation of symptoms suggestive of an underlying malignancy. He was provisionally diagnosed with peritoneal carcinomatosis of an unknown primary. His initial presentation triggered a series of investigations, surgery and biopsies. Omental biopsy specimens were suggestive of IgG4-RD. Despite appropriate treatment for IgG4-RD, his disease progressed, specifically in the lungs. Pleural biopsies were then collected and assessed alongside the omental biopsies. On review and reassessment, the patient was formally diagnosed with RDD.

Objective To determine the frequency of the prozone effect in patients with IgG4-related disease (IgG4-RD). Methods After identifying the prozone effect in an index patient with IgG4-RD, we examined additional samples to determine the frequency of this phenomenon. Thirty-eight serum samples obtained from patients with IgG4-RD whose results had been reported previously were retested. The serum IgG4 concentrations determined by this repeat analysis were compared with the originally reported values. Results In 10 (26%) of 38 patients, the originally reported IgG4 values were falsely low; the prozone effect was identified in each of these 10 samples. Correction of the prozone effect by sample dilution led to revision of the mean serum IgG4 concentration in the 10 samples, from 26 mg/dl to 2,008 mg/dl (normal range 2.4–121 mg/dl). All 10 patients whose samples were affected by the prozone effect had active IgG4-RD. Failure to detect the elevated serum IgG4 concentrations had a direct impact on the decision not to institute treatment in these patients. Conclusion The prozone effect may lead to major underestimations of IgG4 concentrations in patients with IgG4-RD and offers a potential explanation for the poor correlation observed between disease activity and serum IgG4 levels in some patients. This phenomenon should be considered if the serum IgG4 measurement appears discordant with the clinicopathologic diagnosis and the clinical assessment of disease activity.

Hypertrophic pachymeningitis (HP) is an inflammatory condition in which the dura mater of the cranium or spine becomes thickened, leading to symptoms that result from mass effect, nerve compression, or vascular compromise. The differential diagnosis of HP includes immune-mediated conditions such as rheumatoid arthritis and vasculitis, malignancies, and infections. Many times, no diagnosis is reached; in such cases, the disease has been described as idiopathic HP. IgG4-related disease (IgG4-RD) is a recently described inflammatory condition known to cause tumefactive lesions at myriad anatomical locations. Both IgG4-RD and idiopathic HP share similar demographics, histopathology, and natural history. We hypothesized that IgG4-RD is a common cause of idiopathic HP. To investigate this hypothesis, we identified all pathology specimens diagnosed as noninfectious HP during 25 years at our institution. Fourteen cases had stained slides and paraffin blocks to permit review of the original hematoxylin and eosin stained slides as well as immunostaining of cell blocks. Recently published consensus guidelines describing characteristic histopathology and the necessary quantity of IgG4+ plasma cell infiltrate were used to diagnose IgG4-RD. Four cases (66.6%) that had been regarded previously as representing idiopathic HP were diagnosed as IgG4-RD; of all the reviewed cases, IgG4-RD represented 29% of cases. Of the remaining cases, 3 cases were associated with granulomatosis with polyangiitis (GPA), 2 with lymphoma, and 1 each with rheumatoid arthritis, giant cell arteritis, and sarcoidosis. Two of the cases could not be diagnosed more precisely and were classified as undifferentiated HP. Clinical history, serologic tests, cerebrospinal fluid studies, and radiology alone could not identify the cause of HP. Rather, biopsy with histopathology and immunostaining was necessary to reach an accurate diagnosis. Significant IgG4+ plasma cell infiltrates were observed in rheumatoid arthritis, granulomatosis with polyangiitis, and lymphoma, underscoring the importance of histopathology in making the diagnosis of IgG4-RD. This case series demonstrates that IgG4-RD may be the most common etiology of noninfectious HP and highlights the necessity of biopsy for accurate diagnosis.

Idiopathic retroperitoneal fibrosis (RPF) is a periaortic sclerotic disease that encases adjacent retroperitoneal structures, particularly the ureters. A subset of idiopathic RPF cases can be associated with IgG4-related disease, but the frequency of this association is not clear. We selected 23 cases of idiopathic RPF and identified IgG4-related RPF cases based on the presence of IgG4+ plasma cells in the tissue, using an IgG4/IgG ratio cutoff of >40%. We then compared the IgG4-related RPF patients and the non-IgG4-related RPF patients in terms of both the presence of histopathologic features typical of IgG4-related disease and the simultaneous occurrence (or history) of other organ manifestations typical of IgG4-related disease. The IgG4-related RPF and non-IgG4-related RPF groups were also analyzed in terms of clinical, laboratory, and radiologic features and treatment review. We identified 13 cases of IgG4-related RPF (57% of the total cohort). The distinguishing features of IgG4-related RPF were histopathologic and extra-organ manifestations of IgG4-related disease. The IgG4-related RPF patients were statistically more likely than non-IgG4-related RPF patients to have retroperitoneal biopsies showing lymphoplasmacytic infiltrate (p = 0.006), storiform fibrosis (p = 0.006), or tissue eosinophilia (p = 0.0002). Demographics of the 2 groups, including a middle-aged, male predominance (mean age, 58 yr; 73% male), were similar. IgG4-related disease accounts for a substantial percentage of patients with “idiopathic” RPF. Histopathologic features such as storiform fibrosis, obliterative phlebitis, and tissue eosinophilia are critical to identifying this disease association. Extraretroperitoneal manifestations of IgG4-related disease are also often present among patients with IgG4-related RPF. Elevated IgG4/total IgG ratios in tissue biopsies are more useful than the number of IgG4+ plasma cells per high-power field in cases of RPF that are highly fibrotic.

Patients with IgG4-related disease (IgG4-RD) typically have elevated serum concentrations of IgG4 and share histopathologic features that are similar across affected organ(s). IgG4-RD patients frequently require prolonged treatment with glucocorticoids and are often unable to taper these medications. Traditional disease-modifying antirheumatic drugs (DMARDs) are generally ineffective. We assessed the clinical and serologic responses to B lymphocyte depletion therapy in 10 consecutive patients with steroid- and DMARD-refractory IgG4-RD.Ten patients with IgG4-RD were treated with rituximab (RTX) (2 infusions of 1000 mg, 15 days apart). Clinical improvement was assessed by monitoring the patient's ability to taper prednisone to discontinuation and to stop DMARDs; by serial measurements of total IgG and IgG subclasses; and by follow-up radiologic assessments guided by the patient's particular pattern of organ involvement. We also developed and retrospectively applied the IgG4-RD Disease Activity Index and Flare Tool.Organ involvement included the pancreas, biliary tree, aorta, salivary glands (submandibular and parotid), lacrimal glands, lymph nodes, thyroid gland, and retroperitoneum. Nine of 10 patients demonstrated striking clinical improvement within 1 month of starting RTX. One patient with advanced thyroid fibrosis associated with Riedel thyroiditis and a history of disease in multiple other organ systems did not have improvement in the thyroid gland, but the disease did not progress to involve new organs. All 10 patients were able to discontinue prednisone and DMARDs following RTX therapy. Significant decreases in IgG concentrations were observed for the IgG4 subclass only. Four patients were re-treated with RTX after 6 months because of either symptom recurrence and increasing IgG4 concentration at the time of peripheral B cell reconstitution (n = 2) or because of physician discretion (n = 2). Repeated courses of RTX maintained their effectiveness and resulted in further decreases in IgG4 concentrations. In patients who had an increased IgG4 concentration at the time of presentation, the level of serum IgG4 appeared to be a reliable measure of disease activity.IgG4-RD is an idiopathic, multiorgan inflammatory disease in which diverse organ manifestations are linked by characteristic histopathologic and immunohistochemical features. Treatment with RTX led to prompt clinical and serologic improvement in refractory IgG4-RD in all patients with active inflammation. Serial treatments with RTX may lead to progressive declines in serum IgG4 concentrations and better disease control. Serum IgG4 concentrations may remain low, and clinical disease activity may remain quiescent even after B cell reconstitution in a significant proportion of patients.

Hepatitis B virus (HBV) reactivation is defined as a shift from negative to positive hepatitis B surface antigen (HBsAg), or new HBV DNA detection or its rise compared with baseline (Supplemental Table 1, Appendix 1, available at [www.cmaj.ca/lookup/suppl/doi:10.1503/cmaj.180389/-/DC1][1]).[1][2]