Complement Biosensors Identify a Classical Pathway Stimulus in Complement-Mediated Thrombotic Microangiopathy.

Complement-mediated thrombotic microangiopathy or hemolytic uremic syndrome (CM-TMA/CM-HUS), previously identified as atypical hemolytic uremic syndrome, is a thrombotic microangiopathy characterized by germline variants or acquired antibodies to complement proteins and regulators. Building upon our prior experience with the modified Ham (mHam) assay for ex vivo diagnosis of complementopathies, we have developed an array of cell-based complement "biosensors' by selective removal of complement regulatory proteins (CD55 and CD59, CD46, or a combination thereof) in an autonomously bioluminescent HEK293 cell line. These biosensors can be used as a sensitive method for diagnosing CM-TMA and monitoring therapeutic complement blockade. Using specific complement pathway inhibitors, this model identifies IgM-driven classical pathway stimulus during both acute disease and in many patients during clinical remission. This provides a potential explanation for ~50% of CM-TMA patients who lack an alternative pathway "driving" variant and suggests at least a subset of CM-TMA is characterized by a breakdown of IgM immunologic tolerance.

An expert discussion on the atypical hemolytic uremic syndrome nomenclature-identifying a road map to precision: a report of a National Kidney Foundation Working Group.

The term atypical hemolytic uremic syndrome has been in use since the mid-1970s. It was initially used to describe the familial or sporadic form of hemolytic uremic syndrome as opposed to the epidemic, typical form of the disease. Over time, the atypical hemolytic uremic syndrome term has evolved into being used to refer to anything that is not Shiga toxin-associated hemolytic uremic syndrome. The term describes a heterogeneous group of diseases of disparate causes, a circumstance that makes defining disease-specific natural history and/or targeted treatment approaches challenging. A working group of specialty-specific experts in the thrombotic microangiopathies was convened to review the validity of this broad term in an era of swiftly advancing science and targeted therapeutics. A Delphi approach was used to define and interrogate some of the key issues related to the atypical hemolytic uremic syndrome nomenclature.

Familial hypokalemic periodic paralysis: a case induced by concurrent hyperthyroidism.

BACKGROUND: Familial hypokalemic periodic paralysis (HypoPP) is an uncommon genetic disorder characterized by recurrent episodes of muscle weakness and hypokalemia, typically starting in early adulthood. The existence of hyperthyroidism in the presence of HypoPP is more strongly associated with a diagnosis of thyrotoxic periodic paralysis (TPP), with most cases occurring in Asian males with pathogenic KCNJ2 or KCNJ18 variants and without a family history of the condition. This case is novel due to the combination of familial HypoPP and hyperthyroidism induced by Graves' disease, a rare occurrence especially in non-Asian populations. CASE PRESENTATION: A 40-year-old African American man presented with profound muscle weakness after consuming a high-salt meal. He had a significant family history of hyperthyroidism and hypokalemia. On examination, he showed profound weakness in all extremities. Laboratory tests confirmed hypokalemia and hyperthyroidism, and genetic testing identified a pathogenic variant in the CACNA1S gene (c.1583 G > A, p. R528H), with normal SCN4A, KCNJ2 and KCNJ18 sequencing. He was diagnosed with familial HypoPP and hyperthyroidism due to Graves' disease. He was started on PO methimazole 10 mg three times a day and PO acetazolamide 250 mg twice a day. He was advised to follow a low carbohydrate and low salt diet. CONCLUSIONS: This case highlights the importance of considering a genetic basis for HypoPP in patients with a family history of the condition, even when hyperthyroidism is present. The combination of familial HypoPP and Graves' disease is rare and emphasizes the need for careful genetic and clinical evaluation in similar cases. Management should focus on correcting hypokalemia, treating hyperthyroidism, and lifestyle modifications to prevent recurrence.

A very complicated UTI: malakoplakia following E. coli urinary tract infection.

Malakoplakia is a rare inflammatory disorder believed to result from a defect in macrophage phagocytic function triggering a granulomatous reaction. It can present with genitourinary, gastrointestinal, or cutaneous manifestations in immunocompromised or, less commonly, immunocompetent hosts. We describe a case of renal malakoplakia in a young, otherwise healthy patient presenting with nephromegaly and sepsis following an E. coli urinary tract infection. We discuss diagnosis and management, including antibiotic selection and the decision to pursue nephrectomy. This case highlights the potential for kidney recovery with prolonged antibiotic therapy in conjunction with adjunct immunomodulatory therapies and source control.

Therapeutic Plasma Exchange: Core Curriculum 2023.

From producing individual blood components for transfusion to the removal of pathogenic substances, apheresis is a cornerstone of modern medical therapies. The use of therapeutic plasma exchange (TPE), in which plasma and its soluble constituents are removed from the body in exchange for a replacement fluid, can be organ- and life-saving in many diseases. Given the notable similarities between TPE and hemodialysis, the nephrologist is often responsible for managing TPE. As such, one must be familiar with the technologies, approach to therapy, indications for use, and complications. TPE uses centrifugation or membrane separation technologies, with the latter able to be performed with certain hemodialysis machines familiar to the nephrologist. Furthermore, primary kidney diseases such as anti-glomerular basement membrane disease are frequently associated with autoantibodies, potentially making them ideal candidates for TPE. Nevertheless, the use of TPE in many kidney diseases is controversial because of the lack of supporting evidence. This review discusses TPE from the perspective of a nephrologist responsible for prescribing and managing TPE, as well as nephrologists engaged in the care of patients undergoing the procedure.

Evaluation of Plasma Biomarkers to Predict Major Adverse Kidney Events in Hospitalized Patients With COVID-19.

RATIONALE & OBJECTIVE: Patients hospitalized with COVID-19 are at increased risk for major adverse kidney events (MAKE). We sought to identify plasma biomarkers predictive of MAKE in patients hospitalized with COVID-19. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: A total of 576 patients hospitalized with COVID-19 between March 2020 and January 2021 across 3 academic medical centers. EXPOSURE: Twenty-six plasma biomarkers of injury, inflammation, and repair from first available blood samples collected during hospitalization. OUTCOME: MAKE, defined as KDIGO stage 3 acute kidney injury (AKI), dialysis-requiring AKI, or mortality up to 60 days. ANALYTICAL APPROACH: Cox proportional hazards regression to associate biomarker level with MAKE. We additionally applied the least absolute shrinkage and selection operator (LASSO) and random forest regression for prediction modeling and estimated model discrimination with time-varying C index. RESULTS: The median length of stay for COVID-19 hospitalization was 9 (IQR, 5-16) days. In total, 95 patients (16%) experienced MAKE. Each 1 SD increase in soluble tumor necrosis factor receptor 1 (sTNFR1) and sTNFR2 was significantly associated with an increased risk of MAKE (adjusted HR [AHR], 2.30 [95% CI, 1.86-2.85], and AHR, 2.26 [95% CI, 1.73-2.95], respectively). The C index of sTNFR1 alone was 0.80 (95% CI, 0.78-0.84), and the C index of sTNFR2 was 0.81 (95% CI, 0.77-0.84). LASSO and random forest regression modeling using all biomarkers yielded C indexes of 0.86 (95% CI, 0.83-0.89) and 0.84 (95% CI, 0.78-0.91), respectively. LIMITATIONS: No control group of hospitalized patients without COVID-19. CONCLUSIONS: We found that sTNFR1 and sTNFR2 are independently associated with MAKE in patients hospitalized with COVID-19 and can both also serve as predictors for adverse kidney outcomes. PLAIN-LANGUAGE SUMMARY: Patients hospitalized with COVID-19 are at increased risk for long-term adverse health outcomes, but not all patients suffer long-term kidney dysfunction. Identification of patients with COVID-19 who are at high risk for adverse kidney events may have important implications in terms of nephrology follow-up and patient counseling. In this study, we found that the plasma biomarkers soluble tumor necrosis factor receptor 1 (sTNFR1) and sTNFR2 measured in hospitalized patients with COVID-19 were associated with a greater risk of adverse kidney outcomes. Along with clinical variables previously shown to predict adverse kidney events in patients with COVID-19, both sTNFR1 and sTNFR2 are also strong predictors of adverse kidney outcomes.

Age of Onset and Disease Course in Biopsy-Proven Minimal Change Disease: An Analysis From the Cure Glomerulonephropathy Network.

RATIONALE & OBJECTIVE: Adolescent- and adult-onset minimal change disease (MCD) may have a clinical course distinct from childhood-onset disease. We characterized the course of children and adults with MCD in the Cure Glomerulonephropathy Network (CureGN) and assessed predictors of rituximab response. STUDY DESIGN: Prospective, multicenter, observational study. STUDY PARTICIPANTS: CureGN participants with proven MCD on biopsy. EXPOSURE: Age at disease onset, initiation of renin-angiotensin-aldosterone system (RAAS) blockade, and immunosuppression including rituximab during the study period. OUTCOME: Relapse and remission, change in estimated glomerular filtration rate (eGFR), and kidney failure. ANALYTICAL APPROACH: Remission and relapse probabilities were estimated using Kaplan-Meier curves and gap time recurrent event models. Linear regression models were used for the outcome of change in eGFR. Cox proportional hazards models were used to estimate the association between rituximab administration and remission. RESULTS: The study included 304 childhood- (≤12 years old), 49 adolescent- (13-17 years old), and 201 adult- (≥18 years) onset participants with 2.7-3.2 years of follow-up after enrollment. Children had a longer time to biopsy (238 vs 23 and 36 days in adolescent- and adult-onset participants, respectively; P<0.001) and were more likely to have received therapy before biopsy. Children were more likely to be treated with immunosuppression but not RAAS blockade. The rate of relapse was higher in childhood- versus adult-onset participants (HR, 1.69 [95% CI, 1.29-2.21]). The probability of remission was also higher in childhood-onset disease (HR, 1.33 [95%CI, 1.02-1.72]). In all groups eGFR loss was minimal. Children were more likely to remit after rituximab than those with adolescent- or adult-onset disease (adjusted HR, 2.1; P=0.003). Across all groups, glucocorticoid sensitivity was associated with a greater likelihood of achieving complete remission after rituximab (adjusted HR, 2.62; P=0.002). LIMITATIONS: CureGN was limited to biopsy-proven disease. Comparisons of childhood to nonchildhood cases of MCD may be subject to selection bias, given that childhood cases who undergo a biopsy may be limited to patients who are least responsive to initial therapy. CONCLUSIONS: Among patients with MCD who underwent kidney biopsy, there were differences in the course (relapse and remission) of childhood-onset compared with adolescent- and adult-onset disease, as well as rituximab response. PLAIN-LANGUAGE SUMMARY: Minimal change disease is a biopsy diagnosis for nephrotic syndrome. It is diagnosed in childhood, adolescence, or adulthood. Patients and clinicians often have questions about what to expect in the disease course and how to plan therapies. We analyzed a group of patients followed longitudinally as part of the Cure Glomerulonephropathy Network (CureGN) and describe the differences in disease (relapse and remission) based on the age of onset. We also analyzed rituximab response. We found that those with childhood-onset disease had a higher rate of relapse but also have a higher probability of reaching remission when compared with adolescent- or adult-onset disease. Children and all steroid-responsive patients are more likely to achieve remission after rituximab.

Racial and Ethnic Disparities in Acute Care Utilization Among Patients With Glomerular Disease.

RATIONALE & OBJECTIVE: The effects of race, ethnicity, socioeconomic status (SES), and disease severity on acute care utilization in patients with glomerular disease are unknown. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 1,456 adults and 768 children with biopsy-proven glomerular disease enrolled in the Cure Glomerulonephropathy (CureGN) cohort. EXPOSURE: Race and ethnicity as a participant-reported social factor. OUTCOME: Acute care utilization defined as hospitalizations or emergency department visits. ANALYTICAL APPROACH: Multivariable recurrent event proportional rate models were used to estimate associations between race and ethnicity and acute care utilization. RESULTS: Black or Hispanic participants had lower SES and more severe glomerular disease than White or Asian participants. Acute care utilization rates were 45.6, 29.5, 25.8, and 19.2 per 100 person-years in Black, Hispanic, White, and Asian adults, respectively, and 55.8, 42.5, 40.8, and 13.0, respectively, for children. Compared with the White race (reference group), Black race was significantly associated with acute care utilization in adults (rate ratio [RR], 1.76 [95% CI, 1.37-2.27]), although this finding was attenuated after multivariable adjustment (RR, 1.31 [95% CI, 1.03-1.68]). Black race was not significantly associated with acute care utilization in children; Asian race was significantly associated with lower acute care utilization in children (RR, 0.32 [95% CI 0.14-0.70]); no significant associations between Hispanic ethnicity and acute care utilization were identified. LIMITATIONS: We used proxies for SES and lacked direct information on income, household unemployment, or disability. CONCLUSIONS: Significant differences in acute care utilization rates were observed across racial and ethnic groups in persons with prevalent glomerular disease, although many of these difference were explained by differences in SES and disease severity. Measures to combat socioeconomic disadvantage in Black patients and to more effectively prevent and treat glomerular disease are needed to reduce disparities in acute care utilization, improve patient wellbeing, and reduce health care costs.

Baseline Clinical Characteristics and Complement Biomarkers of Patients with C3 Glomerulopathy Enrolled in Two Phase 2 Studies Investigating the Factor D Inhibitor Danicopan.

INTRODUCTION: C3 glomerulopathy (C3G) is a rare, progressive kidney disease resulting from dysregulation of the alternative pathway (AP) of complement. Biomarkers at baseline were investigated in patients with C3G who participated in two phase 2 studies with the factor D (FD) inhibitor, danicopan. METHODS: Patients with biopsy-confirmed C3G, proteinuria ≥500 mg/day, and estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m2 were enrolled into two studies (NCT03369236 and NCT03459443). Biomarker analysis was performed for patients with C3G confirmed by central pathology laboratory re-evaluation. Complement and clinical biomarkers, biopsy composite score, and activity and chronicity indices were assessed at baseline and analyzed by pairwise Spearman correlation analysis. RESULTS: Twenty-nine patients were included in the analysis (median [interquartile range] age: 24.0 [10.0] years). Systemic complement AP activation was evident by reduced median concentrations of C3 and C5, elevated sC5b-9, and normal C4, relative to reference ranges. C3 showed strong pairwise correlations with C5 and sC5b-9 (r = 0.80 and -0.73, respectively; p < 0.0001). Baseline Ba and FD concentrations were inversely correlated with eGFR (r = -0.83 and -0.87, respectively; p < 0.0001). Urinary concentrations of sC5b-9 were correlated with both plasma sC5b-9 and proteinuria (r = 0.69 and r = 0.83, respectively; p < 0.0001). Biopsy activity indices correlated strongly with biomarkers of systemic AP activation, including C3 (r = -0.76, p < 0.0001), whereas chronicity indices aligned more closely with eGFR (r = -0.57, p = 0.0021). CONCLUSION: Associations among complement biomarkers, kidney function, and kidney histology may add to the current understanding of C3G and assist with the characterization of patients with this heterogenous disease.

Clinical Outcomes of Patients with C3G or IC-MPGN Treated with the Factor D Inhibitor Danicopan: Final Results from Two Phase 2 Studies.

INTRODUCTION: C3 glomerulopathy (C3G) is an ultrarare, chronic and progressive nephropathy mediated by dysregulation of the alternative pathway of complement (AP), with poor prognosis and limited treatment options. Targeted inhibition of proximal AP through factor D (FD) blockade represents a rational treatment approach. We present two phase 2 proof-of-concept clinical studies of the orally active FD inhibitor danicopan in patients with C3G and immune complex-mediated membranoproliferative glomerulonephritis (IC-MPGN) (NCT03369236 and NCT03459443). METHODS: A double-blind, placebo-controlled study in patients with C3G and a single-arm, open-label study in patients with C3G or IC-MPGN treated with danicopan are reported. The studies evaluated pharmacokinetic/pharmacodynamic (PK/PD), efficacy, and safety outcomes. The co-primary endpoints were change from baseline in composite biopsy score and the proportion of patients with a 30% reduction in proteinuria relative to baseline at 6 or 12 months. RESULTS: Optimal systemic concentrations of danicopan were not achieved for complete and sustained inhibition of AP, although there was evidence that blockade of FD reduced AP activity shortly after drug administration. Consequently, limited clinical response was observed in key efficacy endpoints. While stable disease or improvement from baseline was seen in some patients, response was not consistent. The data confirmed the favorable safety profile of danicopan. CONCLUSION: While demonstrating a favorable safety profile, danicopan resulted in incomplete and inadequately sustained inhibition of AP, probably due to limitations in its PK/PD profile in C3G, leading to lack of efficacy. Complete and sustained AP inhibition is required for a clinical response in patients with C3G.

Improving Primary Care Delivery for Patients Receiving Maintenance Hemodialysis.

The beneficial impact of primary care, focused on all aspects of a patient's health (rather than a disease-specific focus) is well established. Recognized benefits include greater receipt of preventive care and counseling, lower use of emergency care and hospitalization for ambulatory care-sensitive conditions, and decreased early mortality. Although the importance of primary care and care coordination at the primary care/specialty interface is well recognized, the role of primary care within traditional and emerging care models for patients receiving in-center maintenance hemodialysis remains ill-defined. In this perspective article, we will describe: (1) the role of primary care for patients receiving maintenance hemodialysis and the current evidence regarding the receipt of primary care among these patients; (2) the key challenges to delivery of primary care in these complex cases, including suboptimal care coordination between nephrology and primary care providers, the intensity of dialysis care, and the limited capacity of nephrologists and primary care providers to meet the broad health needs of hemodialysis patients; (3) potential strategies for improving the delivery of primary care for patients receiving hemodialysis; and (4) future research requirements to improve primary care delivery for this high-risk population.

Reduced ADAMTS13 activity during TTP remission is associated with stroke in TTP survivors.

With timely and effective treatment, most patients with thrombotic thrombocytopenic purpura (TTP) survive the acute TTP episode. In addition to the risk of relapse, TTP survivors have higher all-cause mortality than the general population and increased rates of chronic morbidities, including hypertension, depression, and mild cognitive impairment. We conducted this retrospective-prospective cohort study to determine the incidence and prevalence of stroke after recovery from acute TTP and to test the hypothesis that lower ADAMTS13 activity after recovery from TTP is associated with an increased risk of stroke during remission. Of 170 consecutive patients treated for TTP at The Johns Hopkins Hospital from 1995 through 2018, 14 (8.2%) died during the index episode and 19 were observed for less than 1 month after recovery. Of the remaining 137 patients, 18 (13.1%) developed stroke unrelated to an acute TTP episode over a median observation period of 3.08 years, which is fivefold higher than the expected prevalence of 2.6% from an age- and sex-matched reference population (P = .002). ADAMTS13 activity during remission was measured in 52 patients and was >70% in 44.2%, 40% to 70% in 23.1%, 10% to 39% in 25%, and <10% in 7.7%. Stroke after recovery from acute TTP occurred in 0% (0 of 22) of patients with normal remission ADAMTS13 activity (>70%) and in 27.6% (8 of 29) of patients with low ADAMTS13 activity (≤70%; P = .007). In conclusion, stroke is common after recovery from TTP and is associated with reduced ADAMTS13 activity during remission.

Higher Prevalence of Concurrent Thrombocytopenia in Patients Receiving Continuous Renal Replacement Therapy in the Cardiac Intensive Care Unit.

INTRODUCTION: Thrombocytopenia (TCP) is a common finding in patients receiving continuous renal replacement therapy (CRRT). OBJECTIVE: The purpose of this study was to assess the nature of TCP in patients receiving CRRT. METHODS: This is a single-center case-control observational study of 795 patients involving over 166,950 h of delivered CRRT at Johns Hopkins Hospital. Concurrent TCP in patients receiving CRRT was defined as a decrease in platelet count of ≥50% any time within 72 h of initiation of CRRT with strict exclusion criteria. RESULTS: There was a higher incidence of TCP in the cardiac intensive care unit (CICU) (22.5%) compared to medical ICU (MICU) (13.1%). Using logistic regression, the odds of developing concurrent TCP in patients receiving CRRT was 2.46 (95% CI 1.32-3.57, p < 0.05) times higher in the CICU compared with the MICU. There was no difference in the incidence of severe or profound TCP or timing of acute TCP between the CICU and MICU. CONCLUSION: Safe delivery of dialysis care in the ICU is paramount and creating awareness of potential risks such as concurrent TCP in patients receiving CRRT should be part of this care.

Mutation of complement factor B causing massive fluid-phase dysregulation of the alternative complement pathway can result in atypical hemolytic uremic syndrome.

Atypical hemolytic uremic syndrome is an ultra-rare disease characterized by microangiopathic hemolytic anemia, thrombocytopenia and acute kidney injury. Its pathogenesis is driven most frequently by dysregulated cell-surface control of the alternative pathway of complement secondary to inherited and/or acquired factors. Here we evaluated two unrelated patients with atypical hemolytic uremic syndrome. The first, a five-year-old Caucasian female, presented at 10 months with schistocytes, thrombocytopenia and kidney injury. The second, a 55-year-old Caucasian female, presented at age 31 following caesarean section for preeclampsia. Complement biomarker testing was remarkable for undetectable levels of C3 in both. Circulating levels of C5 and properdin were also low consistent with over-activity of the alternative and terminal pathways of complement. Genetic testing identified a heterozygous novel variant in CFB (c.1101 C>A, p.Ser367Arg) in both patients. Functional studies found strong fluid-phase C3 cleavage when normal and proband sera were mixed. Cell-surface C3b deposition was strongly positive when patient serum was supplemented with C3. In vitro control of C3 convertase activity could be restored with increased concentrations of factor H. Thus, CFB p.Ser367Arg is a gain-of-function pathogenic variant that leads to dysregulation of the alternative pathway in the fluid-phase and increased C3b deposition on cell surfaces. Our study highlights the complexities of complement-mediated diseases like atypical hemolytic uremic syndrome and illustrates the importance of functional studies at the variant level to gain insight into the disease phenotype.

Ex vivo assays to detect complement activation in complementopathies.

In complement-driven thrombotic microangiopathies, failure to regulate complement activation leads to end-organ damage. The modified Ham (mHam) test measures complement-mediated killing of a nucleated cell in vitro but lacks a confirmatory assay and reliable positive controls. We demonstrate that C5b-9 accumulation on the surface of TF1 PIGAnull cells correlates with cell killing in the mHam. We also show that Sialidase treatment of cells or addition of Shiga toxin 1 to human serum serve as a more reliable positive control for the mHam than cobra venom factor or lipopolysaccharide. Simultaneously performing the mHam and measuring C5b-9 accumulation either in GVB++ or GVB0 MgEGTA buffer with the addition of complement pathway specific inhibitors (anti-C5 antibody or a factor D inhibitor, ACH-145951) can be used to localize defects in complement regulation. As more targeted complement inhibitors become available, these assays may aid in the selection of personalized treatments for patients with complement-mediated diseases.

The COVID-19 nephrology compendium: AKI, CKD, ESKD and transplantation.

The pandemic of coronavirus disease 2019 (CoVID-19) has been an unprecedented period. The disease afflicts multiple organ systems, with acute kidney injury (AKI) a major complication in seriously ill patients. The incidence of AKI in patients with CoVID-19 is variable across numerous international studies, but the high incidence of AKI and its associated worse outcomes in the critical care setting are a consistent finding. A multitude of patterns and mechanisms of AKI have been elucidated, and novel strategies to address shortage of renal replacement therapy equipment have been implemented. The disease also has had consequences on longitudinal management of patients with chronic kidney disease and end stage kidney disease. Kidney transplant recipients may be especially susceptible to CoVID-19 as a result of immunosuppression, with preliminary studies demonstrating high mortality rates. Increased surveillance of disease with low threshold for testing and adjustment of immunosuppression regimen during acute periods of illness have been recommended.

Primary Care Physicians' Perceived Barriers to Nephrology Referral and Co-management of Patients with CKD: a Qualitative Study.

BACKGROUND: Effective co-management of patients with chronic kidney disease (CKD) between primary care physicians (PCPs) and nephrologists is increasingly recognized as a key strategy to ensure the delivery of efficient and high-quality CKD care. However, the co-management of patients with CKD remains suboptimal. OBJECTIVE: We aimed to identify PCPs' perceptions of key barriers and facilitators to effective co-management of patients with CKD at the PCP-nephrology interface. STUDY DESIGN: Qualitative study SETTING AND PARTICIPANTS: Community-based PCPs in four US cities: Baltimore, MD; St. Louis, MO; Raleigh, NC; and San Francisco, CA APPROACH: We conducted four focus groups of PCPs. Two members of the research team coded transcribed audio-recorded interviews and identified major themes. KEY RESULTS: Most of the 32 PCPs (59% internists and 41% family physicians) had been in practice for > 10 years (97%), spent ≥ 80% of their time in clinical care (94%), and practiced in private (69%) or multispecialty group practice (16%) settings. PCPs most commonly identified barriers to effective co-management of patients with CKD focused on difficulty developing working partnerships with nephrologists, including (1) lack of timely adequate information exchange (e.g., consult note not received or CKD care plan unclear); (2) unclear roles and responsibilities between PCPs and nephrologists; and (3) limited access to nephrologists (e.g., unable to obtain timely consultations or easily contact nephrologists with concerns). PCPs expressed a desire for "better communication tools" (e.g., shared electronic medical record) and clear CKD care plans to facilitate improved PCP-nephrology collaboration. CONCLUSIONS: Interventions facilitating timely adequate information exchange, clear delineation of roles and responsibilities between PCPs and nephrologists, and greater access to specialist advice may improve the co-management of patients with CKD.

What the non-nephrologist needs to know about dialysis.

The End-Stage Renal Disease (ESRD) program now serves approximately 675,000 individuals in the United States at a cost of $26.1 billion to the Medicare system. Given the size of this population, healthcare providers from all disciplines will deliver care to patients on dialysis. Mortality remains high among patients on chronic dialysis, with 42.3% surviving 5 years. As this is a vulnerable population, it is important in the care of ESRD patients that non-nephrologists have a working knowledge of issues germane to dialysis. This review examines the physiology, mechanics, complications, and care delivery concerns of kidney dialysis modalities relevant to the non-nephrologist. The majority of patients receive in-center hemodialysis thrice weekly, with a small proportion on home-based therapies such as peritoneal dialysis or home hemodialysis. Inpatients may undergo hemodialysis or peritoneal dialysis, and in critically ill patients, continuous renal replacement therapies are utilized. Practical aspects of each of these modalities are discussed.

Modified Ham test for atypical hemolytic uremic syndrome.

Atypical hemolytic uremic syndrome (aHUS) is a thrombotic microangiopathy (TMA) characterized by excessive activation of the alternative pathway of complement (APC). Atypical HUS is frequently a diagnosis of exclusion. Differentiating aHUS from other TMAs, especially thrombotic thrombocytopenic purpura (TTP), is difficult due to overlapping clinical manifestations. We sought to develop a novel assay to distinguish aHUS from other TMAs based on the hypothesis that paroxysmal nocturnal hemoglobinuria cells are more sensitive to APC-activated serum due to deficiency of glycosylphosphatidylinositol- anchored complement regulatory proteins (GPI-AP). Here, we demonstrate that phosphatidylinositol-specific phospholipase C-treated EA.hy926 cells and PIGA-mutant TF-1 cells are more susceptible to serum from aHUS patients than parental EA.hy926 and TF-1 cells. We next studied 31 samples from 25 patients with TMAs, including 9 with aHUS and 12 with TTP. Increased C5b-9 deposition was evident by confocal microscopy and flow cytometry on GPI-AP-deficient cells incubated with aHUS serum compared with heat-inactivated control, TTP, and normal serum. Differences in cell viability were observed in biochemically GPI-AP-deficient cells and were further increased in PIGA-deficient cells. Serum from patients with aHUS resulted in a significant increase of nonviable PIGA-deficient TF-1 cells compared with serum from healthy controls (P < .001) and other TMAs (P < .001). The cell viability assay showed high reproducibility, sensitivity, and specificity in detecting aHUS. In conclusion, we developed a simple, rapid, and serum-based assay that helps to differentiate aHUS from other TMAs.

A novel bedside cardiopulmonary physical diagnosis curriculum for internal medicine postgraduate training.

BACKGROUND: Physicians spend less time at the bedside in the modern hospital setting which has contributed to a decline in physical diagnosis, and in particular, cardiopulmonary examination skills. This trend may be a source of diagnostic error and threatens to erode the patient-physician relationship. We created a new bedside cardiopulmonary physical diagnosis curriculum and assessed its effects on post-graduate year-1 (PGY-1; interns) attitudes, confidence and skill. METHODS: One hundred five internal medicine interns in a large U.S. internal medicine residency program participated in the Advancing Bedside Cardiopulmonary Examination Skills (ACE) curriculum while rotating on a general medicine inpatient service between 2015 and 2017. Teaching sessions included exam demonstrations using healthy volunteers and real patients, imaging didactics, computer learning/high-fidelity simulation, and bedside teaching with experienced clinicians. Primary outcomes were attitudes, confidence and skill in the cardiopulmonary physical exam as determined by a self-assessment survey, and a validated online cardiovascular examination (CE). RESULTS: Interns who participated in ACE (ACE interns) by mid-year more strongly agreed they had received adequate training in the cardiopulmonary exam compared with non-ACE interns. ACE interns were more confident than non-ACE interns in performing a cardiac exam, assessing the jugular venous pressure, distinguishing 'a' from 'v' waves, and classifying systolic murmurs as crescendo-decrescendo or holosystolic. Only ACE interns had a significant improvement in score on the mid-year CE. CONCLUSIONS: A comprehensive bedside cardiopulmonary physical diagnosis curriculum improved trainee attitudes, confidence and skill in the cardiopulmonary examination. These results provide an opportunity to re-examine the way physical examination is taught and assessed in residency training programs.