Circulating cytokine and chemokine patterns associated with cytomegalovirus reactivation after stem cell transplantation.

Objectives: Human cytomegalovirus (HCMV) reactivation is the leading viral complication after allogeneic haematopoietic stem cell transplantation (allo-HSCT). Understanding of circulating cytokine/chemokine patterns which accompany HCMV reactivation and correlate with HCMV DNAemia magnitude is limited. We aimed to characterise plasma cytokine/chemokine profiles in 36 allo-HSCT patients (21 with HCMV reactivation and 15 without HCMV reactivation) at four time-points in the first 100-day post-transplant. Methods: The concentrations of 31 cytokines/chemokines in plasma samples were analysed using a multiplex bead-based immunoassay. Cytokine/chemokine concentrations were compared in patients with high-level HCMV DNAemia, low-level HCMV DNAemia or no HCMV reactivation, and correlated with immune cell frequencies measured using mass cytometry. Results: Increased plasma levels of T helper 1-type cytokines/chemokines (TNF, IL-18, IP-10, MIG) were detected in patients with HCMV reactivation at the peak of HCMV DNAemia, relative to non-reactivators. Stem cell factor (SCF) levels were significantly higher before the detection of HCMV reactivation in patients who went on to develop high-level HCMV DNAemia (810-52 740 copies/mL) vs. low-level HCMV DNAemia (< 250 copies/mL). High-level HCMV reactivators, but not low-level reactivators, developed an elevated inflammatory cytokine/chemokine profile (MIP-1α, MIP-1ß, TNF, LT-α, IL-13, IL-9, SCF, HGF) at the peak of reactivation. Plasma cytokine concentrations displayed unique correlations with circulating immune cell frequencies in patients with HCMV reactivation. Conclusion: This study identifies distinct circulating cytokine/chemokine signatures associated with the magnitude of HCMV DNAemia and the progression of HCMV reactivation after allo-HSCT, providing important insight into immune recovery patterns associated with HCMV reactivation and viral control.

Development and Validation of a Formative Assessment Tool for Nephrology Fellows' Clinical Reasoning.

BACKGROUND: Diagnostic errors are commonly driven by failures in clinical reasoning. Deficits in clinical reasoning are common among graduate medical learners, including nephrology fellows. We created and validated an instrument to assess clinical reasoning in a national cohort of nephrology fellows and established performance thresholds for remedial coaching. METHODS: Experts in nephrology education and clinical reasoning remediation designed an instrument to measure clinical reasoning through a written patient encounter note from a web-based, simulated AKI consult. The instrument measured clinical reasoning in three domains: problem representation, differential diagnosis with justification, and diagnostic plan with justification. Inter-rater reliability was established in a pilot cohort ( n =7 raters) of first-year nephrology fellows using a two-way random effects agreement intraclass correlation coefficient model. The instrument was then administered to a larger cohort of first-year fellows to establish performance standards for coaching using the Hofstee method ( n =6 raters). RESULTS: In the pilot cohort, there were 15 fellows from four training program, and in the study cohort, there were 61 fellows from 20 training programs. The intraclass correlation coefficients for problem representation, differential diagnosis, and diagnostic plan were 0.90, 0.70, and 0.50, respectively. Passing thresholds (% total points) in problem representation, differential diagnosis, and diagnostic plan were 59%, 57%, and 62%, respectively. Fifty-nine percent ( n =36) met the threshold for remedial coaching in at least one domain. CONCLUSIONS: We provide validity evidence for a simulated AKI consult for formative assessment of clinical reasoning in nephrology fellows. Most fellows met criteria for coaching in at least one of three reasoning domains, demonstrating a need for learner assessment and instruction in clinical reasoning.

Structural and Psychosocial Challenges Among Underserved Patients Receiving Hemodialysis During and Beyond the COVID-19 Pandemic: A Qualitative Study.

Rationale & Objective: Racial and ethnic minority groups in the United States are disproportionately affected by chronic kidney disease and progressive kidney failure and face significantly more socioeconomic and psychosocial challenges. However, how such patients' social environment and stigmatization shape their illness experiences and abilities to cope before and during the coronavirus disease 2019 (COVID-19) pandemic has not been well documented, even as social scientific research predicts these groups' exponential vulnerability. Study Design: Qualitative study using semistructured interviews to elicit individual patient narratives about their personal illness experiences before and during the COVID-19 pandemic, any challenges they faced, and their sources of support. Setting & Participants: Using purposive sampling, we recruited 20 adult patients receiving maintenance hemodialysis from centers affiliated with a safety-net hospital in Boston, Massachusetts. Analytical Approach: Interviews were audiotaped, transcribed, and analyzed using thematic content analysis to identify patients' challenges and supports before and during the pandemic. Results: Of the 20 patients in the study, 9 were women, and 18 self-identified as Black or African American. Three main themes emerged, whereby most patients described: (1) stigma and stigmatization as a central element of their life experience; (2) the pandemic as a difficult experience but not a complete rupture from their prepandemic life; and (3) social networks, particularly family, friends, and religious communities, as sources of support crucial to coping with their debilitating illness. Limitations: Whether the findings apply to other settings is unknown, as participants were recruited from centers in a single safety-net urban hospital setting. Conclusions: Psychosocial and environmental factors, including institutional racism and stigmatization, play significant roles in amplifying the burdens shouldered by racial and ethnic minority individuals with kidney disease who now also face the COVID-19 pandemic that has since turned endemic. The results of this study can inform the development of policy interventions aimed at alleviating tensions and structural conditions that impinge on kidney disease patients' wellbeing and health outcomes. Plain-Language Summary: Members of racial and ethnic minority groups in the United States experience the highest rates of progressive kidney failure and face significantly more socioeconomic and psychosocial challenges. We interviewed 20 patients who receive maintenance hemodialysis treatment from centers affiliated with a safety-net hospital. Patients described stigmatization as a central element of their life experience and the pandemic as a difficult challenge (but not a complete rupture) that added to their struggles with illness-related, race-related, and class-related stigmas. Social networks, particularly family, friends, and religious communities, are key sources of support crucial to coping with illness. Findings from this study can inform health care providers and community workers and guide the development of policy interventions to provide better support for these patients.

A Retrograde Implantation Approach for Peritoneal Dialysis Catheter Placement in Mice.

Murine models are employed to probe various aspects of peritoneal dialysis (PD), such as peritoneal inflammation and fibrosis. These events drive peritoneal membrane failure in humans, which remains an area of intense investigation due to its profound clinical implications in managing patients with end-stage kidney disease (ESKD). Despite the clinical importance of PD and its related complications, current experimental murine models suffer from key technical challenges that compromise the models' performance. These include PD catheter migration and kinking and usually warrant earlier catheter removal. These limitations also drive the need for a greater number of animals to complete a study. Addressing these drawbacks, this study introduces technical improvements and surgical nuances to prevent commonly observed PD catheter complications in a murine model. Moreover, this modified model is validated by inducing peritoneal inflammation and fibrosis using lipopolysaccharide injections. In essence, this paper describes an improved method to create an experimental model of PD.

Immunoprofiling reveals cell subsets associated with the trajectory of cytomegalovirus reactivation post stem cell transplantation.

Human cytomegalovirus reactivation is a major opportunistic infection after allogeneic haematopoietic stem cell transplantation and has a complex relationship with post-transplant immune reconstitution. Here, we use mass cytometry to define patterns of innate and adaptive immune cell reconstitution at key phases of human cytomegalovirus reactivation in the first 100 days post haematopoietic stem cell transplantation. Human cytomegalovirus reactivation is associated with the development of activated, memory T-cell profiles, with faster effector-memory CD4+ T-cell recovery in patients with low-level versus high-level human cytomegalovirus DNAemia. Mucosal-associated invariant T cell levels at the initial detection of human cytomegalovirus DNAemia are significantly lower in patients who subsequently develop high-level versus low-level human cytomegalovirus reactivation. Our data describe distinct immune signatures that emerged with human cytomegalovirus reactivation after haematopoietic stem cell transplantation, and highlight Mucosal-associated invariant T cell levels at the first detection of reactivation as a marker that may be useful to anticipate the magnitude of human cytomegalovirus DNAemia.

Predictors and outcomes of acute kidney injury during autologous stem cell transplantation in AL amyloidosis.

BACKGROUND: Acute kidney injury (AKI) is a common complication after high-dose melphalan and autologous stem cell transplantation (HDM/SCT) in patients with light chain (AL) amyloidosis. However, its incidence, predictors and outcomes are not well known. METHODS: This observational study included 223 patients with AL amyloidosis who underwent HDM/SCT. AKI was defined as an increase in serum creatinine to ≥1.5 times the baseline occurring within the first 30 days of HDM/SCT. RESULTS: The median age was 58 years (range: 30-77). Kidney and cardiac involvement were present in 86.1% and 56.8%, respectively. The median estimated glomerular filtration rate (eGFR) was 83.5 mL/min/1.73 m2 (range: 9-213) and proteinuria was 2899 mg/day (range: 0-19 966). AKI occurred in 29.1% of patients. Dialysis was initiated in 15 patients (6.7%) and of these 12 (80%) were able to discontinue dialysis. Most of the episodes of AKI occurred within the first 2 weeks; with a median follow-up of 4.5 years (range: 0.1-16.5), AKI was associated with increased overall mortality [hazard rato (HR) = 4.53, 95% confidence interval (CI) 2-10.23]. The 10-year overall survival was 87.1% without AKI, versus 56.9% with AKI. AKI was also associated with an increased risk for end-stage kidney disease (ESKD) (HR = 4.6, 95% CI 1.44-14.38). The risk of developing ESKD at 10 years was 18.9% with AKI, versus 8.1% without AKI. Several risk factors were found and using multivariate logistic regression, a prediction model was developed that included three readily available variables: eGFR <60 mL/min/1.73 m2, interventricular septal thickness in diastole >12 mm and albumin <3 g/dL. This model was able to predict AKI development with an area under the curve of 0.8. CONCLUSIONS: AKI is common in the post-HDM/SCT period and it leads to increased risk for ESKD and death. Our prediction model is an easily deployable tool in clinical settings as part of the discussion with patients who are being prepared for HDM/SCT.

Mass cytometry reveals immune signatures associated with cytomegalovirus (CMV) control in recipients of allogeneic haemopoietic stem cell transplant and CMV-specific T cells.

OBJECTIVES: Cytomegalovirus (CMV) is known to have a significant impact on immune recovery post-allogeneic haemopoietic stem cell transplant (HSCT). Adoptive therapy with donor-derived or third-party virus-specific T cells (VST) can restore CMV immunity leading to clinical benefit in prevention and treatment of post-HSCT infection. We developed a mass cytometry approach to study natural immune recovery post-HSCT and assess the mechanisms underlying the clinical benefits observed in recipients of VST. METHODS: A mass cytometry panel of 38 antibodies was utilised for global immune assessment (72 canonical innate and adaptive immune subsets) in HSCT recipients undergoing natural post-HSCT recovery (n = 13) and HSCT recipients who received third-party donor-derived CMV-VST as salvage for unresponsive CMV reactivation (n = 8). RESULTS: Mass cytometry identified distinct immune signatures associated with CMV characterised by a predominance of innate cells (monocytes and NK) seen early and an adaptive signature with activated CD8+ T cells seen later. All CMV-VST recipients had failed standard antiviral pharmacotherapy as a criterion for trial involvement; 5/8 had failed to develop the adaptive immune signature by study enrolment despite significant CMV antigen exposure. Of these, VST administration resulted in development of the adaptive signature in association with CMV control in three patients. Failure to respond to CMV-VST in one patient was associated with persistent absence of the adaptive immune signature. CONCLUSION: The clinical benefit of CMV-VST may be mediated by the recovery of an adaptive immune signature characterised by activated CD8+ T cells.

The Role of Kidney Transplantation in Monoclonal Ig Deposition Disease.

INTRODUCTION: Monoclonal Ig deposition disease (MIDD) frequently leads to kidney failure, and a large proportion of these patients would greatly benefit from kidney transplantation. However, data on kidney transplantation outcomes in MIDD are limited. METHODS: This was a retrospective analysis of long-term renal outcomes of 23 patients with MIDD, including 6 patients who underwent kidney transplantation. RESULTS: The 1-, 5-, and 10-year overall survival (OS) from diagnosis were 95%, 78%, and 65%, respectively. Approximately half of the patients (n = 12) progressed to end-stage renal disease (ESRD) with a median time from diagnosis to ESRD of 3.4 years. The 1-, 5-, and 10-year renal survival from diagnosis were 77%, 48%, and 29% respectively. Renal response was observed only in 5 patients (22%), all of them after achieving hematologic complete response. Median OS from diagnosis was significantly better for those who underwent kidney transplantation versus those who remained on dialysis (19.8 years vs. 8.3 years, P = 0.016). Among patients who underwent kidney transplantation, the shortest survival from MIDD diagnosis was 13.7 years and the longest was 27.8 years. Of the 3 patients with kidney transplants who died, the time from the first kidney transplantation to death was 7.4, 18.8, and 20.4 years. Graft loss due to disease recurrence occurred at 4 months and 3.8 years after kidney transplantation in 2 patients who either were not treated or did not respond to treatment. CONCLUSION: As treatments for MIDD have dramatically improved, more patients are achieving sustained hematologic responses with longer patient and graft survival after kidney transplantation.

Profiling the Blood Compartment of Hematopoietic Stem Cell Transplant Patients During Human Cytomegalovirus Reactivation.

Human cytomegalovirus (HCMV) is a widespread pathogen establishing a latent infection in its host. HCMV reactivation is a major health burden in immunocompromised individuals, and is a major cause of morbidity and mortality following hematopoietic stem cell transplantation (HSCT). Here we determined HCMV genomic levels using droplet digital PCR in different peripheral blood mononuclear cell (PBMC) populations in HCMV reactivating HSCT patients. This high sensitivity approach revealed that all PBMC populations harbored extremely low levels of viral DNA at the peak of HCMV DNAemia. Transcriptomic analysis of PBMCs from high-DNAemia samples revealed elevated expression of genes typical of HCMV specific T cells, while regulatory T cell enhancers as well as additional genes related to immune response were downregulated. Viral transcript levels in these samples were extremely low, but remarkably, the detected transcripts were mainly immediate early viral genes. Overall, our data indicate that HCMV DNAemia is associated with distinct signatures of immune response in the blood compartment, however it is not necessarily accompanied by substantial infection of PBMCs and the residual infected PBMCs are not productively infected.

Human Cytomegalovirus Latency and Reactivation in Allogeneic Hematopoietic Stem Cell Transplant Recipients.

Human cytomegalovirus (HCMV) reactivation is a major infectious cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). HCMV is a ubiquitous beta-herpesvirus which asymptomatically infects immunocompetent individuals but establishes lifelong latency, with the potential to reactivate to a life-threatening productive infection when the host immune system is suppressed or compromised. Opportunistic HCMV reactivation is the most common viral complication following engraftment after HSCT and is associated with a marked increase in non-relapse mortality, which appears to be linked to complex effects on post-transplant immune recovery. This minireview explores the cellular sites of HCMV latency and reactivation in HSCT recipients and provides an overview of the risk factors for HCMV reactivation post-HSCT. The impact of HCMV in shaping post-transplant immune reconstitution and its relationship with patient outcomes such as relapse and graft-versus-host disease will be discussed. Finally, we survey current and emerging strategies to prevent and control HCMV reactivation in HSCT recipients, with recent developments including adoptive T cell therapies to accelerate HCMV-specific T cell reconstitution and new anti-HCMV drug therapy for HCMV reactivation after HSCT.

Restriction of Human Cytomegalovirus Infection by Galectin-9.

Human cytomegalovirus (HCMV) is a ubiquitous human herpesvirus. While HCMV infection is generally asymptomatic in the immunocompetent, it can have devastating consequences in those with compromised or underdeveloped immune systems, including transplant recipients and neonates. Galectins are a widely expressed protein family that have been demonstrated to modulate both antiviral immunity and regulate direct host-virus interactions. The potential for galectins to directly modulate HCMV infection has not previously been studied, and our results reveal that galectin-9 (Gal-9) can potently inhibit HCMV infection. Gal-9-mediated inhibition of HCMV was dependent upon its carbohydrate recognition domains and thus dependent on glycan interactions. Temperature shift studies revealed that Gal-9 specific inhibition was mediated primarily at the level of virus-cell fusion and not binding. Additionally, we found that during reactivation of HCMV in hematopoietic stem cell transplant (HSCT) patients soluble Gal-9 is upregulated. This study provides the first evidence for Gal-9 functioning as a potent antiviral defense effector molecule against HCMV infection and identifies it as a potential clinical candidate to restrict HCMV infections.IMPORTANCE Human cytomegalovirus (HCMV) continues to cause serious and often life-threatening disease in those with impaired or underdeveloped immune systems. This virus is able to infect and replicate in a wide range of human cell types, which enables the virus to spread to other individuals in a number of settings. Current antiviral drugs are associated with a significant toxicity profile, and there is no vaccine; these factors highlight a need to identify additional targets for the development of anti-HCMV therapies. We demonstrate for the first time that secretion of a member of the galectin family of proteins, galectin-9 (Gal-9), is upregulated during natural HCMV-reactivated infection and that this soluble cellular protein possesses a potent capacity to block HCMV infection by inhibiting virus entry into the host cell. Our findings support the possibility of harnessing the antiviral properties of Gal-9 to prevent HCMV infection and disease.

Long-term outcome of kidney transplantation in AL amyloidosis.

Therapies for AL amyloidosis have dramatically improved, leading to longer patient survival; however, more AL amyloidosis patients are reaching end-stage renal disease (ESRD). There are no clear guidelines regarding eligibility for kidney transplantation in patients with AL amyloidosis, and data on outcomes are limited. We evaluated the clinical and laboratory data of 49 patients who were followed in the Amyloidosis Center at Boston University and underwent kidney transplantation at a center in the United States between 1987-2017. During a median follow-up of 7.2 years (range 0-19), the median patient survival from diagnosis was 15.4 years, and from kidney transplantation was 10.5 years. One, three, and five-year graft survival were 94%, 89%, and 81%, respectively. Patients with hematologic complete response or very good partial response prior to kidney transplantation had significantly better patient survival than patients with partial response or no response, and the median time to graft loss was 10.4 years versus 5.5 years, respectively. This is the largest published series of kidney transplantation in patients with AL amyloidosis, suggesting that kidney transplantation can have a good outcome in carefully selected patients, particularly in those who have achieved a complete response or very good partial response at the time of kidney transplantation.

Mass Cytometry for the Assessment of Immune Reconstitution After Hematopoietic Stem Cell Transplantation.

Mass cytometry, or Cytometry by Time-Of-Flight, is a powerful new platform for high-dimensional single-cell analysis of the immune system. It enables the simultaneous measurement of over 40 markers on individual cells through the use of monoclonal antibodies conjugated to rare-earth heavy-metal isotopes. In contrast to the fluorochromes used in conventional flow cytometry, metal isotopes display minimal signal overlap when resolved by single-cell mass spectrometry. This review focuses on the potential of mass cytometry as a novel technology for studying immune reconstitution in allogeneic hematopoietic stem cell transplant (HSCT) recipients. Reconstitution of a healthy donor-derived immune system after HSCT involves the coordinated regeneration of innate and adaptive immune cell subsets in the recipient. Mass cytometry presents an opportunity to investigate immune reconstitution post-HSCT from a systems-level perspective, by allowing the phenotypic and functional features of multiple cell populations to be assessed simultaneously. This review explores the current knowledge of immune reconstitution in HSCT recipients and highlights recent mass cytometry studies contributing to the field.

High-Dose Melphalan and Stem Cell Transplantation in Patients on Dialysis Due to Immunoglobulin Light-Chain Amyloidosis and Monoclonal Immunoglobulin Deposition Disease.

The kidney is the most common organ affected by immunoglobulin light-chain (AL) amyloidosis and monoclonal immunoglobulin deposition disease (MIDD), often leading to end-stage renal disease (ESRD). High-dose melphalan and stem cell transplantation (HDM/SCT) is effective for selected patients with AL amyloidosis, with high rates of complete hematologic response and potential for improved organ dysfunction. Data on tolerability and response to HDM/SCT in patients with ESRD due to AL amyloidosis and MIDD are limited. We analyzed data on toxicity, efficacy, and hematologic and renal response of HDM/SCT in 32 patients with AL amyloidosis and 4 patients with MIDD who were dialysis-dependent for ESRD treated at Boston Medical Center between 1994 and 2016. The most common grade 3/4 nonhematologic toxicities were infections (75%), metabolic abnormalities (56%), mucositis (42%), constitutional symptoms (39%), pulmonary complications (39%), and diarrhea (28%). Treatment related mortality (defined as death within 100 days of SCT) occurred in 8% (3 of 36). A complete hematologic response was achieved in 70% of evaluable patients (19 of 27) at 1 year after HDM/SCT. In the entire cohort, median overall survival (OS) after HDM/SCT was 5.8 years; median OS was 1 year for those who did not achieve a complete hematologic response and 8 years for those who did achieve a complete hematologic response. Twelve patients (33%) underwent kidney transplantation after successful treatment with HDM/SCT at a median of 2.4 years after SCT. HDM/SCT is safe and effective in inducing hematologic complete responses and prolonging survival in patients with ESRD from AL amyloidosis and MIDD. Achievement of a durable hematologic response can make these patients possible candidates for renal transplantation.

Bendamustine-Induced Nephrogenic Diabetes Insipidus in a Patient With AL Amyloidosis.

Nephrogenic diabetes insipidus is a condition characterized by polyuria with dilute urine due to the inability of the principal cells of the renal collecting ducts to respond to antidiuretic hormone and concentrate urine. Nephrogenic diabetes insipidus can be drug induced, and several chemotherapeutic agents have been reported to cause it. Bendamustine is a traditional chemotherapeutic agent being studied for treatment for relapsed systemic AL amyloidosis. We report a case of a 59-year-old man with AL amyloidosis who developed partial nephrogenic diabetes insipidus after receiving bendamustine for treatment of AL amyloidosis. The nephrogenic diabetes insipidus responded well to sodium restriction, hydrochlorothiazide, and desmopressin treatment, allowing the patient to receive subsequent bendamustine cycles without polyuria. Nephrogenic diabetes insipidus resolved shortly after completion of bendamustine therapy.

Enhancing Nephrology Career Interest through the ASN Kidney TREKS Program.

The Kidney Tutored Research and Education for Kidney Students (TREKS) Program is a product of the American Society of Nephrology (ASN) Workforce Committee that seeks to connect medical and graduate students to nephrology. This program starts with a weeklong camp-like course introducing participants to renal physiology through classic and modern experiments. Next, each student is matched with a nephrology mentor at his or her home institution to foster a better understanding of a nephrology career. Lastly, the students are encouraged to participate in scholarly activities and attend the ASN Kidney Week. Now in its third year, with a total of 84 participants, survey data suggest early success of the program, with a self-reported 40% increased interest in nephrology fellowship and/or research careers. In addition, students give high ratings to the course components and mentorship pairings. Continued student tracking will be necessary to determine the long-term program effect.