Immune-mediated thrombocytopenia and IL-6-mediated thrombocytosis observed in idiopathic multicentric Castleman disease

Idiopathic multicentric Castleman disease (iMCD) is a rare haematological disorder characterized by generalized lymphadenopathy with atypical histopathological features and systemic inflammation caused by a cytokine storm involving interleukin-6 (IL-6). Three clinical subtypes are recognized: thrombocytopenia, anasarca, fever, renal dysfunction, organomegaly (iMCD-TAFRO); idiopathic plasmacytic lymphadenopathy (iMCD-IPL), involving thrombocytosis and hypergammaglobulinaemia; and iMCD-not otherwise specified (iMCD-NOS), which includes patients who do not meet criteria for the other subtypes. Disease pathogenesis is poorly understood, with potential involvement of infectious, clonal and/or autoimmune mechanisms. To better characterize iMCD clinicopathology and gain mechanistic insights into iMCD, we analysed complete blood counts, other clinical laboratory values and blood smear morphology among 63 iMCD patients grouped by clinical subtype. Patients with iMCD-TAFRO had large platelets, clinical severity associated with lower platelet counts and transfusion-resistant thrombocytopenia, similar to what is observed with immune-mediated destruction of platelets in immune thrombocytopenic purpura. Conversely, elevated platelet counts in iMCD-IPL were associated with elevated IL-6 and declined following anti-IL-6 therapy. Our data suggest that autoimmune mechanisms contribute to the thrombocytopenia in at least a portion of iMCD-TAFRO patients whereas IL-6 drives thrombocytosis in iMCD-IPL, and these mechanisms likely contribute to disease pathogenesis.

Longitudinal, natural history study reveals the disease burden of idiopathic multicentric Castleman disease

Idiopathic multicentric Castleman disease (iMCD) is a rare hematologic disorder with heterogeneous presentations ranging from moderate constitutional symptoms to life-threatening multiorgan system involvement. iMCD patients present with vastly different clinical subtypes, with some patients demonstrating thrombocytopenia, anasarca, fever/elevated C-reactive protein, reticulin fibrosis/renal failure, and organomegaly (TAFRO) and others demonstrating more mild/moderate symptoms with potential for severe disease (not otherwise specified, NOS). Due to its rarity and heterogeneity, the natural history and long-term burden of iMCD are poorly understood. We investigated real-world medical data from ACCELERATE, a large natural history registry of Castleman disease patients, to better characterize the long-term disease burden experienced by these patients. We found that iMCD-TAFRO patients face significant hospitalization burden, requiring more time in the hospital than iMCD-NOS patients during the year surrounding diagnosis (median [IQR] 36 [18, 61] days vs. 0 [0, 4] days; p.

Treatment consistent with idiopathic multicentric Castleman disease guidelines is associated with improved outcomes

Idiopathic multicentric Castleman disease (iMCD) is a rare hematologic disorder with an unknown etiology. Clinical presentation is heterogeneous, ranging from mild constitutional symptoms with lymphadenopathy to life-threatening multiorgan dysfunction. International, consensus treatment guidelines developed in 2018 relied upon a limited number of clinical trials and small case series; however, to our knowledge, real-world performance of these recommendations has not been subsequently studied. Siltuximab, a monoclonal antibody against interleukin 6 (IL6), is approved for the treatment of iMCD and recommended first-line, and tocilizumab, a monoclonal antibody directed against the IL6 receptor, is recommended when siltuximab is unavailable. Chemotherapy, rituximab, and immunomodulators are recommended as second- and third-line treatments based on limited evidence. Corticosteroid monotherapy is used by clinicians, although not recommended. Here, we draw upon the ACCELERATE Natural History Registry to inventory regimens and evaluate regimen response for 102 expert-confirmed iMCD cases. Siltuximab with/without (w/wo) corticosteroids was associated with a 52% response, whereas corticosteroid monotherapy was associated with a 3% response. Anti-IL6-directed therapy with siltuximab or tocilizumab demonstrated better response and more durability than was observed with rituximab w/wo corticosteroids. Cytotoxic chemotherapy was associated with a 52% response and was predominantly administered in patients characterized by thrombocytopenia, anasarca, fever, renal failure/reticulin fibrosis, and organomegaly. Our results provide evidence in support of current recommendations to administer anti-IL6 as first-line treatment, to administer cytotoxic chemotherapy in patients with severe refractory disease, and to limit corticosteroid monotherapy. Evidence remains limited for effective agents for patients who are refractory to anti-IL6-directed therapy. This trial was registered at www.clinicaltrials.gov as #NCT02817997.

CXCL13 is a predictive biomarker in idiopathic multicentric Castleman disease

Idiopathic multicentric Castleman disease (iMCD) is a rare and poorly-understood cytokine storm-driven inflammatory disorder. Interleukin-6 (IL-6) is a known disease driver in some patients, but anti-IL-6 therapy with siltuximab is not effective in all patients, and biomarkers indicating success at an early time point following treatment initiation are lacking. Here we show, by comparison of levels of 1,178 proteins in sera of healthy participants (N = 42), patients with iMCD (N = 88), and with related diseases (N = 60), a comprehensive landscape of candidate disease mediators and predictors of siltuximab response. C-X-C Motif Chemokine Ligand-13 (CXCL13) is identified and validated as the protein most prominently up-regulated in iMCD. Early and significant decrease in CXCL13 levels clearly distinguishes siltuximab responders from non-responders; a 17% reduction by day 8 following siltuximab therapy initiation is predictive of response at later time points. Our study thus suggests that CXCL13 is a predictive biomarker of response to siltuximab in iMCD.

The disease course of Castleman disease patients with fatal outcomes in the ACCELERATE registry

Castleman disease (CD) describes a group of rare, potentially fatal lymphoproliferative disorders. To determine factors associated with mortality in CD, we analysed data from deceased patients in the ACCELERATE registry and compared them with matched controls. We analysed demographic, treatment and laboratory data from all deceased CD patients, matched controls and a subgroup of idiopathic multicentric Castleman disease (iMCD) patients. Of the 140 patients in ACCELERATE with a confirmed CD diagnosis, 10 had died. There were 72 patients with confirmed iMCD; six were deceased. The deceased CD cohort had more hospitalisations per year, higher overall hospitalisations and more days hospitalised per month, and received more treatment regimens per year than the matched‐control group. Analysis of laboratory values showed a significantly decreased absolute lymphocyte count at months 3 and 6 in the deceased cohort compared with controls. Among iMCD patients, there was a higher proportion of iMCD‐TAFRO (thrombocytopenia, anasarca, fever, reticulin myelofibrosis, renal dysfunction and organomegaly) cases in the deceased group. The deceased iMCD group had significantly lower immunoglobulin M, international normalised ratio and platelet count. These data demonstrate that there may be differences between patients who have fatal and non‐fatal outcomes, and provide preliminary suggestions for parameters to evaluate further.

Increased mTORC2 pathway activation in lymph nodes of iMCD-TAFRO

Idiopathic multicentric Castleman disease (iMCD) is a rare and life‐threatening haematologic disorder involving polyclonal lymphoproliferation and organ dysfunction due to excessive cytokine production, including interleukin‐6 (IL‐6). Clinical trial and real‐world data demonstrate that IL‐6 inhibition is effective in 34–50% of patients. mTOR, which functions through mTORC1 and mTORC2, is a recently discovered therapeutic target. The mTOR inhibitor sirolimus, which preferentially inhibits mTORC1, has led to sustained remission in a small cohort of anti‐IL‐6‐refractory iMCD patients with thrombocytopenia, anasarca, fever, renal dysfunction and organomegaly (iMCD‐TAFRO). However, sirolimus has not shown uniform effect, potentially due to its limited mTORC2 inhibition. To investigate mTORC2 activation in iMCD, we quantified the mTORC2 effector protein pNDRG1 by immunohistochemistry of lymph node tissue from six iMCD‐TAFRO and eight iMCD patients who do not meet TAFRO criteria (iMCD‐not‐otherwise‐specified; iMCD‐NOS). mTORC2 activation was increased in all regions of iMCD‐TAFRO lymph nodes and the interfollicular space of iMCD‐NOS compared with control tissue. Immunohistochemistry also revealed increased pNDRG1 expression in iMCD‐TAFRO germinal centres compared with autoimmune lymphoproliferative syndrome (ALPS), an mTOR‐driven, sirolimus‐responsive lymphoproliferative disorder, and comparable staining between iMCD‐NOS and ALPS. These results suggest increased mTORC2 activity in iMCD and that dual mTORC1/mTORC2 inhibitors may be a rational therapeutic approach.

Bone Marrow Findings of Idiopathic Multicentric Castleman Disease: A Histopathologic Analysis and Systematic Literature Review

Idiopathic multicentric Castleman disease (iMCD) is a polyclonal lymphoproliferative disorder characterized by constitutional symptoms, generalized lymphadenopathy, cytopenias, and multi-organ dysfunction due to excessive cytokines, notably Interleukin-6. iMCD is often sub-classified into iMCD-TAFRO, which is associated with thrombocytopenia (T), anasarca (A), fever/elevated C-reactive protein (F), renal dysfunction (R), and organomegaly (O), and iMCD-NOS, which is typically associated with thrombocytosis and hypergammaglobulinemia. The diagnosis of iMCD is challenging as consensus clinico-pathological diagnostic criteria were only recently established and include several non-specific lymph node histopathological features. Identification of further clinico-pathological features commonly found in iMCD could contribute to more accurate and timely diagnoses. We set out to characterize bone marrow (BM) histopathological features in iMCD, assess differences between iMCD-TAFRO and iMCD-NOS, and determine if these findings are specific to iMCD. Examination of BM specimens from 24 iMCD patients revealed a high proportion with hypercellularity, megakaryocytic atypia, reticulin fibrosis, and plasmacytosis across patients with both iMCD-NOS and iMCD-TAFRO with significantly more megakaryocytic hyperplasia (p=0.001) in the iMCD-TAFRO cases. These findings were also consistent with bone marrow findings from 185 published cases of iMCD-NOS and iMCD-TAFRO. However, these findings are relatively nonspecific as they can be seen in various other infectious, malignant, and autoimmune diseases. This article is protected by copyright. All rights reserved.

Validated international definition of the thrombocytopenia, anasarca, fever, reticulin fibrosis, renal insufficiency, and organomegaly clinical subtype (TAFRO) of idiopathic multicentric Castleman disease

Thrombocytopenia, anasarca, fever, reticulin fibrosis, renal insufficiency, and organomegaly (TAFRO) syndrome is a heterogeneous entity manifesting with a constellation of symptoms described above that can occur in the context of idiopathic multicentric Castleman disease (iMCD) as well as infectious diseases, malignancies, and rheumatologic disorders. So, iMCD-TAFRO is an aggressive subtype of iMCD with TAFRO syndrome and often hyper-vascularized lymph nodes. Since we proposed diagnostic criteria of iMCD-TAFRO in 2016, we have accumulated new insights on the disorder and additional cases have been reported worldwide. In this systematic review and cohort analysis, we established and validated a definition for iMCD-TAFRO. First, we searched PubMed and Japan Medical Abstracts Society databases using the keyword "TAFRO" to extract cases. Patients with possible systemic autoimmune diseases and hematologic malignancies were excluded. Our search identified 54 cases from 50 articles. We classified cases into three categories: (1) iMCD-TAFRO (TAFRO syndrome with lymph node histopathology consistent with iMCD), (2) possible iMCD-TAFRO (TAFRO syndrome with no lymph node biopsy performed and no other co-morbidities), and (3) TAFRO without iMCD or other co-morbidities (TAFRO syndrome with lymph node histopathology not consistent with iMCD or other comorbidities). Based on the findings, we propose an international definition requiring four clinical criteria (thrombocytopenia, anasarca, fever/hyperinflammatory status, organomegaly), renal dysfunction or characteristic bone marrow findings, and lymph node features consistent with iMCD. The definition was validated with an external cohort (the ACCELERATE Natural History Registry). The present international definition will facilitate a more precise and comprehensive approach to the diagnosis of iMCD-TAFRO.

Emerging role of 18F-FDG PET/CT in Castleman disease: a review

Castleman disease (CD) describes a group of rare hematologic conditions involving lymphadenopathy with characteristic histopathology and a spectrum of clinical abnormalities. CD is divided into localized or unicentric CD (UCD) and multicentric CD (MCD) by imaging. MCD is further divided based on etiological driver into human herpesvirus-8-associated MCD, POEMS-associated MCD, and idiopathic MCD. There is notable heterogeneity across MCD, but increased level of pro-inflammatory cytokines, particularly interleukin-6, is an established disease driver in a portion of patients. FDG-PET/CT can help determine UCD versus MCD, evaluate for neoplastic conditions that can mimic MCD clinico-pathologically, and monitor therapy responses. CD requires more robust characterization, earlier diagnosis, and an accurate tool for both monitoring and treatment response evaluation; FDG-PET/CT is particularly suited for this. Moving forward, future prospective studies should further characterize the use of FDG-PET/CT in CD and specifically explore the utility of global disease assessment and dual time point imaging.

Trial registration ClinicalTrials.gov, NCT02817997, Registered 29 June 2016, https://clinicaltrials.gov/ct2/show/NCT02817997

ACCELERATE: A Patient-Powered Natural History Study Design Enabling Clinical and Therapeutic Discoveries in a Rare Disorder

Geographically dispersed patients, inconsistent treatment tracking, and limited infrastructure slow research for many orphan diseases. We assess the feasibility of a patient-powered study design to overcome these challenges for Castleman disease, a rare hematologic disorder. Here, we report initial results from the ACCELERATE natural history registry. ACCELERATE includes a traditional physician-reported arm and a patient-powered arm, which enables patients to directly contribute medical data and biospecimens. This study design enables successful enrollment, with the 5-year minimum enrollment goal being met in 2 years. A median of 683 clinical, laboratory, and imaging data elements are captured per patient in the patient-powered arm compared with 37 in the physician-reported arm. These data reveal subgrouping characteristics, identify off-label treatments, support treatment guidelines, and are used in 17 clinical and translational studies. This feasibility study demonstrates that the direct-to-patient design is effective for collecting natural history data and biospecimens, tracking therapies, and providing critical research infrastructure.

Treatments Administered to the First 9152 Reported Cases of COVID-19: A Systematic Review

The emergence of SARS-CoV-2/2019 novel coronavirus (COVID-19) has created a global pandemic with no approved treatments or vaccines. Many treatments have already been administered to COVID-19 patients but have not been systematically evaluated. We performed a systematic literature review to identify all treatments reported to be administered to COVID-19 patients and to assess time to clinically meaningful response for treatments with sufficient data. We searched PubMed, BioRxiv, MedRxiv, and ChinaXiv for articles reporting treatments for COVID-19 patients published between 1 December 2019 and 27 March 2020. Data were analyzed descriptively. Of the 2706 articles identified, 155 studies met the inclusion criteria, comprising 9152 patients. The cohort was 45.4% female and 98.3% hospitalized, and mean (SD) age was 44.4 years (SD 21.0). The most frequently administered drug classes were antivirals, antibiotics, and corticosteroids, and of the 115 reported drugs, the most frequently administered was combination lopinavir/ritonavir, which was associated with a time to clinically meaningful response (complete symptom resolution or hospital discharge) of 11.7 (1.09) days. There were insufficient data to compare across treatments. Many treatments have been administered to the first 9152 reported cases of COVID-19. These data serve as the basis for an open-source registry of all reported treatments given to COVID-19 patients at www.CDCN.org/CORONA . Further work is needed to prioritize drugs for investigation in well-controlled clinical trials and treatment protocols.

Castleman disease spectrum

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Background: Castleman disease (CD) describes a group of lymphoproliferative disorders that share characteristic histopathology. Unicentric CD (UCD) and idiopathic multicentric CD (iMCD) are differentiated by the number of enlarged lymph node (LN) regions: UCD involves 1 region and iMCD involves > 1 region. UCD typically has mild or no symptoms whereas iMCD requires abnormal labs and symptoms for diagnosis and can progress to life-threatening multi-organ failure. Review of an international natural history registry of CD revealed patients across a broad spectrum with regards to number of enlarged LN regions and disease severity. We hypothesize that there is a positive correlation between disease activity and the number of enlarged LNs and that the spectrum of CD is more complex than a binary UCD-iMCD dichotomy. Methods: Herein, enrolled UCD and iMCD patients whose diagnosis was confirmed by an expert-panel were selected for analysis (N = 81). A standardized disease activity score (scale 0-1) was computed for each patient using available diagnostic values of C-reactive protein, hemoglobin, and albumin (CHA score). Results: We looked at the association between number of enlarged LNs and CHA and found a significant positive correlation (R = 0.65, p < 0.0001). Given this, we divided the cohort into groups of mild, moderate, and extensive lymphadenopathy according to the number of regions of enlarged LNs at the time of diagnosis: group 1 (1 enlarged LN region); group 2 (2-4 enlarged LN regions); and group 3 (≥5 enlarged LN regions). We identified 20 patients in group 1, 19 in group 2, and 42 in group 3 with no statistical differences in sex, race, or age at diagnosis. Histopathological subtype differed significantly among groups. Group 1 was 89% hyaline vascular (HV)/ hypervascular (HpV) and 11% mixed (Mx); group 2 was 74% HV/HpV, 21% Mx, and 5% plasmacytic (Pl); and group 3 was 64% HV/HpV, 32% Mx, and 5% Pl. We then looked at CHA score in these groups and found that group 3 patients have a significantly greater CHA score (median [IQR]: 0.46 [0.49]) than both group 2 (0.08 [0.14]) and group 1 (0.0 [0.10]) (adjusted p < 0.001 for both) while there was no difference between groups 1 and 2. Conclusions: These results suggest that disease severity is positively associated with the number of enlarged LNs. The different proportions of histopathological subtypes between the three groups could indicate different pathologic mechanisms are involved. Further work is needed to determine if patients with a few enlarged LNs exhibit disease more closely to UCD or iMCD and to understand long-term outcomes for these patients.

Type I IFN response associated with mTOR activation in the TAFRO subtype of idiopathic multicentric Castleman disease

The TAFRO clinical subtype of idiopathic multicentric Castleman disease (iMCD-TAFRO) is a rare hematologic illness involving episodic disease flares of thrombocytopenia, anasarca, fever, reticulin myelofibrosis, renal dysfunction, and organomegaly (TAFRO) and progressive multiple organ dysfunction. We previously showed that the mTOR signaling pathway is elevated in lymph nodes of iMCD-TAFRO patients and that an mTOR inhibitor is effective in a small cohort of patients. However, the upstream mechanisms, cell types, and mediators involved in disease pathogenesis remain unknown. Here, we developed a targeted approach to identify candidate cellular drivers and mechanisms in iMCD-TAFRO through cellular and transcriptomic studies. Using paired iMCD-TAFRO PBMC samples collected during flare and remission, we identified T cell activation and alterations in NK cell and monocyte subset frequencies during iMCD-TAFRO flare. These changes were associated with increased Type I IFN (IFN-I) response gene signatures across CD8+ T cells, NK cells, and monocytes. Finally, we found that IFN-β stimulation of monocytes and T cells from iMCD-TAFRO patient remission samples induced increased mTOR activation compared with healthy donors, and this was abrogated with either mTORC1 or JAK1/2 inhibition. The data presented here support a potentially novel role for IFN-I signaling as a driver of increased mTOR signaling in iMCD-TAFRO.

Increased mTOR activation in idiopathic multicentric Castleman disease

Idiopathic multicentric Castleman disease (iMCD) is a rare and poorly understood hematologic disorder characterized by lymphadenopathy, systemic inflammation, cytopenias, and life-threatening multiorgan dysfunction. Interleukin-6 (IL-6) inhibition effectively treats approximately one-third of patients. Limited options exist for nonresponders, because the etiology, dysregulated cell types, and signaling pathways are unknown. We previously reported 3 anti-IL-6 nonresponders with increased mTOR activation who responded to mTOR inhibition with sirolimus. We investigated mTOR signaling in tissue and serum proteomes from iMCD patients and controls. mTOR activation was increased in the interfollicular space of iMCD lymph nodes (N = 26) compared with control lymph nodes by immunohistochemistry (IHC) for pS6, p4EBP1, and p70S6K, known effectors and readouts of mTORC1 activation. IHC for pS6 also revealed increased mTOR activation in iMCD compared with Hodgkin lymphoma, systemic lupus erythematosus, and reactive lymph nodes, suggesting that the mTOR activation in iMCD is not just a product of lymphoproliferation/inflammatory lymphadenopathy. Further, the degree of mTOR activation in iMCD was comparable to autoimmune lymphoproliferative syndrome, a disease driven by mTOR hyperactivation that responds to sirolimus treatment. Gene set enrichment analysis of serum proteomic data from iMCD patients (n = 88) and controls (n = 42) showed significantly enriched mTORC1 signaling. Finally, functional studies revealed increased baseline mTOR pathway activation in peripheral monocytes and T cells from iMCD remission samples compared with healthy controls. IL-6 stimulation augmented mTOR activation in iMCD patients, which was abrogated with JAK1/2 inhibition. These findings support mTOR activation as a novel therapeutic target for iMCD, which is being investigated through a trial of sirolimus (NCT03933904).

A Type I interferon response is associated with increased mTOR activation in idiopathic multicentric Castleman disease

Idiopathic multicentric Castleman disease (iMCD) is a deadly hematologic illness of unknown etiology involving episodic disease flares characterized by systemic inflammation and multiple organ system dysfunction. We previously showed that the mTOR signaling pathway is elevated in lymph nodes of iMCD patients and that an mTOR inhibitor is effective in preventing disease flares in a small cohort of patients. However, the upstream mechanisms and the cell types and mediators involved in disease pathogenesis remain unknown. Here, we developed a targeted approach to identify candidate cellular drivers and mechanisms in iMCD through flow cytometric and single-cell transcriptomic analysis. Using paired PBMC samples collected from ten iMCD patients during flare and later following resolution of flare (remission), we identified increased T cell activation and alterations in NK cell and monocyte subset frequencies during iMCD flare. These changes were associated with increased Type I Interferon (IFN-I) response gene signatures across CD8+ T cells, NK cells, and monocytes as well as mTOR signaling gene signatures within monocytes. Finally, we demonstrated that increased mTOR activation in iMCD may occur downstream of IFN-I signaling as we observed significantly greater induction of pS6, a readout of mTOR activation, in monocytes and T cells from iMCD remission samples compared to healthy donors. Importantly, this IFN-I-mediated mTOR activation can be abrogated through treatment with the JAKi, ruxolitinib. The data presented here corroborate the notion of widespread systemic inflammation during iMCD disease flare and suggest a role for hyperresponsiveness to IFN-I as a mechanistic driver of increased mTOR signaling in iMCD.

Identifying and targeting pathogenic PI3K/AKT/mTOR signaling in IL-6-blockade-refractory idiopathic multicentric Castleman disease

BACKGROUND

Idiopathic multicentric Castleman disease (iMCD) is a hematologic illness involving cytokine-induced lymphoproliferation, systemic inflammation, cytopenias, and life-threatening multi-organ dysfunction. The molecular underpinnings of interleukin-6(IL-6)-blockade refractory patients remain unknown; no targeted therapies exist. In this study, we searched for therapeutic targets in IL-6-blockade refractory iMCD patients with the thrombocytopenia, anasarca, fever/elevated C-reactive protein, reticulin myelofibrosis, renal dysfunction, organomegaly (TAFRO) clinical subtype.

METHODS

We analyzed tissues and blood samples from three IL-6-blockade refractory iMCD-TAFRO patients. Cytokine panels, quantitative serum proteomics, flow cytometry of PBMCs, and pathway analyses were employed to identify novel therapeutic targets. To confirm elevated mTOR signaling, a candidate therapeutic target from the above assays, immunohistochemistry was performed for phosphorylated S6, a read-out of mTOR activation, in three iMCD lymph node tissue samples and controls. Proteomic, immunophenotypic, and clinical response assessments were performed to quantify the effects of administration of the mTOR inhibitor, sirolimus.

RESULTS

Studies of three IL-6-blockade refractory iMCD cases revealed increased CD8+ T cell activation, VEGF-A, and PI3K/Akt/mTOR pathway activity. Administration of sirolimus significantly attenuated CD8+ T cell activation and decreased VEGF-A levels. Sirolimus induced clinical benefit responses in all three patients with durable and ongoing remissions of 66, 19, and 19 months.

CONCLUSION

This precision medicine approach identifies PI3K/Akt/mTOR signaling as the first pharmacologically-targetable pathogenic process in IL-6-blockade refractory iMCD. Prospective evaluation of sirolimus in treatment-refractory iMCD is planned (NCT03933904).

FUNDING

Castleman's Awareness & Research Effort/Castleman Disease Collaborative Network, Penn Center for Precision Medicine, University Research Foundation, Intramural NIH funding, and National Heart Lung and Blood Institute.

Plasma proteomics identifies a 'chemokine storm' in idiopathic multicentric Castleman disease

Human Herpesvirus-8 (HHV-8)-negative/idiopathic multicentric Castleman disease (iMCD) is a poorly understood disease involving polyclonal lymphoproliferation with dysmorphic germinal centers, constitutional symptoms, and multi-organ failure. Patients can experience thrombocytopenia, anasarca, reticulin fibrosis, renal dysfunction, organomegaly, and normal immunoglobulin levels, - iMCD-TAFRO. Others experience thrombocytosis, milder effusions, and hypergammaglobulinemia, -iMCD-Not Otherwise Specified (iMCD-NOS). Though the etiology is unknown in both subtypes, iMCD symptoms and disease progression are believed to be driven by a cytokine storm, often including interleukin-6 (IL-6). However, approximately two-thirds of patients do not respond to anti-IL-6 therapy; alternative drivers and signaling pathways are not known for anti-IL-6 nonresponders. To identify potential mediators of iMCD pathogenesis, we quantified 1129 proteins in 13 plasma samples from six iMCD patients during flare and remission. The acute phase reactant NPS-PLA2 was the only significantly increased protein (P = .017); chemokines and complement were significantly enriched pathways. Chemokines represented the greatest proportion of upregulated cytokines, suggesting that iMCD involves a chemokine storm. The chemokine CXCL13, which is essential in homing B cells to germinal centers, was the most upregulated cytokine across all patients (log2 fold-change = 3.22). Expression of CXCL13 was also significantly increased in iMCD lymph node germinal centers compared to controls in a stromal meshwork pattern. We observed distinct proteomic profiles between the two iMCD-TAFRO patients, who both failed anti-IL-6-therapy, and the four iMCD-NOS patients, in whom all three treated with anti-IL-6-therapy responded, suggesting that differing mechanisms may exist. This study reveals proteomic differences between flare and remission and the potential to molecularly define iMCD subgroups.

Three-Year Outcomes of Bariatric Surgery vs Lifestyle Intervention for Type 2 Diabetes Mellitus Treatment: A Randomized Clinical Trial

IMPORTANCE

Questions remain about the role and durability of bariatric surgery for type 2 diabetes mellitus (T2DM).

OBJECTIVE

To compare the remission of T2DM following surgical and nonsurgical treatments.

DESIGN, SETTING, AND PARTICIPANTS

In this 3-arm randomized clinical trial conducted at the University of Pittsburgh Medical Center from October 1, 2009, to June 26, 2014, in Pittsburgh, Pennsylvania, outcomes were assessed 3 years after treating 61 obese participants aged 25 to 55 years with T2DM. Analysis was conducted with an intent-to-treat population.

INTERVENTIONS

Participants were randomized to either an intensive lifestyle weight loss intervention for 1 year followed by a low-level lifestyle intervention for 2 years or surgical treatments (Roux-en-Y gastric bypass [RYGB] or laparoscopic adjustable gastric banding [LAGB]) followed by low-level lifestyle intervention in years 2 and 3.

MAIN OUTCOMES AND MEASURES

Primary end points were partial and complete T2DM remission and secondary end points included diabetes medications and weight change.

RESULTS

Body mass index (calculated as weight in kilograms divided by height in meters squared) was less than 35 for 26 participants (43%), 50 (82%) were women, and 13 (21%) were African American. Mean (SD) values were 100.5 (13.7) kg for weight, 47.3 (6.6) years for age, 7.8% (1.9%) for hemoglobin A1c level, and 171.3 (72.5) mg/dL for fasting plasma glucose level. Partial or complete T2DM remission was achieved by 40% (n = 8) of RYGB, 29% (n = 6) of LAGB, and no intensive lifestyle weight loss intervention participants (P = .004). The use of diabetes medications was reduced more in the surgical groups than the lifestyle intervention-alone group, with 65% of RYGB, 33% of LAGB, and none of the intensive lifestyle weight loss intervention participants going from using insulin or oral medication at baseline to no medication at year 3 (P < .001). Mean (SE) reductions in percentage of body weight at 3 years were the greatest after RYGB at 25.0% (2.0%), followed by LAGB at 15.0% (2.0%) and lifestyle treatment at 5.7% (2.4%) (P < .01).

CONCLUSIONS AND RELEVANCE

Among obese participants with T2DM, bariatric surgery with 2 years of an adjunctive low-level lifestyle intervention resulted in more disease remission than did lifestyle intervention alone.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT01047735.

Urinary Incontinence Before and After Bariatric Surgery

IMPORTANCE

Among women and men with severe obesity, evidence for improvement in urinary incontinence beyond the first year after bariatric surgery-induced weight loss is lacking.

OBJECTIVES

To examine change in urinary incontinence before and after bariatric surgery and to identify factors associated with improvement and remission among women and men in the first 3 years after bariatric surgery.

DESIGN, SETTING, AND PARTICIPANTS

The Longitudinal Assessment of Bariatric Surgery 2 is an observational cohort study at 10 US hospitals in 6 geographically diverse clinical centers. Participants were recruited between February 21, 2005, and February 17, 2009. Adults undergoing first-time bariatric surgical procedures as part of clinical care by participating surgeons between March 14, 2006, and April 24, 2009, were followed up for 3 years (through October 24, 2012).

INTERVENTION

Participants undergoing bariatric surgery completed research assessments before the procedure and annually thereafter.

MAIN OUTCOMES AND MEASURES

The frequency and type of urinary incontinence episodes in the past 3 months were assessed using a validated questionnaire. Prevalent urinary incontinence was defined as at least weekly urinary incontinence episodes, and remission was defined as change from prevalent urinary incontinence at baseline to less than weekly urinary incontinence episodes at follow-up.

RESULTS

Of 2458 participants, 1987 (80.8%) completed baseline and follow-up assessments. At baseline, the median age was 47 years (age range, 18-78 years), the median body mass index was 46 kg/m2 (range, 34-94 kg/m2), and 1565 of 1987 (78.8%) were women. Urinary incontinence was more prevalent among women (49.3%; 95% CI, 46.9%-51.9%) than men (21.8%; 95% CI, 18.2%-26.1%) (P < .001). After a mean 1-year weight loss of 29.5% (95% CI, 29.0%-30.1%) in women and 27.0% (95% CI, 25.9%-28.6%) in men, year 1 urinary incontinence prevalence was significantly lower among women (18.3%; 95% CI, 16.4%-20.4%) and men (9.8%; 95% CI, 7.2%-13.4%) (P < .001 for all). The 3-year prevalence was higher than the 1-year prevalence for both sexes (24.8%; 95% CI, 21.8%-26.5% among women and 12.2%; 95% CI, 9.0%-16.4% among men) but was substantially lower than baseline (P < .001 for all). Weight loss was independently related to urinary incontinence remission (relative risk, 1.08; 95% CI, 1.06-1.10 in women and 1.07; 95% CI, 1.02-1.13 in men) per 5% weight loss, as were younger age and the absence of a severe walking limitation.

CONCLUSIONS AND RELEVANCE

Among women and men with severe obesity, bariatric surgery was associated with substantially reduced urinary incontinence over 3 years. Improvement in urinary incontinence may be an important benefit of bariatric surgery.

Pharmacokinetic profiles in rats after intravenous, oral, or dermal administration of dapsone

Dapsone is a potent anti-inflammatory and antibacterial agent that has been used extensively in the oral treatment of leprosy and dermatitis herpetiformis. This study compared the pharmacokinetic profile of dapsone in rats given a single oral or i.v. 12 mg/kg dose (n = 8/group) or a single dermal application of 12 or 60 mg/kg (n = 12/group) in an aqueous gel application medium containing 10 or 25% diethylene glycol monoethyl ether (DGME). Blood samples (200 microl) were collected via tail vein from each rat and pooled at intervals up to the 24-h period. A terminal blood sample was collected by cardiac puncture from each animal. Plasma concentrations of dapsone were determined by liquid chromatography atmospheric pressure ionization tandem mass spectroscopy. There was no treatment-related overt toxicity observed in any of the animals. Peak levels were reached 1 h after oral dosing (4890 ng/ml), and 6 to 8 h after dermal application, with Cmax values of 1.62, 5.56, and 12.8 ng/ml, for 12 mg/kg at 10 or 25% DGME, and for 60 mg/kg at 25% DGME, respectively. Bioavailability was calculated at 78% after oral dosing and <1% after dermal application. Apparent elimination half-lives (t(1/2))s were similar after i.v. and oral dosing. Both the calculated area under the plasma concentration versus time curve up to 24 h and Cmax values were 3- to 4-fold higher in the dermal application group administered 12 mg/kg dapsone in 25 versus 10% DGME gel, whereas the calculated area under the plasma concentration versus time curve up to 24 h and Cmax values for the 60 mg/kg group were only 3.3- and 2.3-fold greater than those obtained after application of 12 mg/kg in 25% DGME. These results show that both systemic exposure and peak plasma concentrations of dapsone are minimized by dermal versus oral administration of the compound.