Pre-transplant glomerular hyperfiltration is not a risk factor for increased renal morbidity and mortality in pediatric stem cell transplant patients

Low glomerular filtration rate (GFR) prior to stem cell transplant (SCT) is associated with increased morbidity and mortality. The implications of abnormally high GFRs, or glomerular hyperfiltration, prior to SCT are unknown. Twenty-two of 74 consecutive pediatric SCT patients over 2 years old at a single center were hyperfiltrating prior to SCT, median nuclear medicine GFR 154 mL/min/1.73 m2 [interquartile range: 146-170]. There was no association between hyperfiltration and any transplant demographics, nor between hyperfiltration and acute kidney injury (p = .8), renal replacement therapy (p = .63), 1-year event-free survival (p = 1), or abnormal creatinine-based estimated GFR at a median follow-up of 4.7 years (p = .73).

Ionized Magnesium Correlates With Total Blood Magnesium in Pediatric Patients Following Kidney Transplant

Background

Abnormal serum magnesium (Mg) concentrations are common and associated with worse mortality in kidney-transplant recipients. Many kidney and transplant-related factors affect Mg homeostasis. The concentration of the active form, ionized Mg (iMg), is not measured clinically, and total Mg (tMg) and iMg correlations have conflicted. We hypothesized that iMg and tMg concentrations show poor categorical agreement (i.e., low, normal, and high) in kidney-transplant recipients but that ionized calcium (iCa) correlates with iMg.

Methods

We retrospectively evaluated hypomagnesemia in kidney-transplant recipients over a 2-yr period. We prospectively collected blood at 0-28 days post-transplant to measure correlations between iMg and iCa/tMg. iMg and iCa concentrations in the reference ranges of 0.44-0.65 and 1.0-1.3 mmol/L, respectively, were considered normal. Fisher's exact test and unweighted kappa statistics revealed category agreements. Pearson's correlation coefficients and linear regression measured correlations.

Results

Among 58 retrospective kidney-transplant recipients, 54 (93%) had tMg<0.66 mmol/L, 28/58 (48%) received Mg supplementation, and 20/28 (71%) had tacrolimus dose adjustments during supplementation. In 13 prospective transplant recipients (N=43 samples), iMg and tMg showed strong category agreement (P=0.0003) and correlation (r=0.71, P<0.001), whereas iMg and iCa did not (P=0.7; r=-0.25, P=0.103, respectively).

Conclusions

tMg and iMg exhibited strong correlation following kidney transplantation. However, iCa may not be an accurate surrogate for iMg. Determining the effect of Mg supplementation and the Mg concentration where supplementation is clinically necessary are important next steps.

Urinary Biomarkers for the Assessment of Acute Kidney Injury of Pediatric Sickle Cell Anemia Patients Admitted for Severe Vaso-occlusive Crises

Sickle cell nephropathy is a progressive morbidity, beginning in childhood, which is incompletely understood partially due to insensitive measures. We performed a prospective pilot study of pediatric and young adult patients with sickle cell anemia (SCA) to assess urinary biomarkers during acute pain crises. Four biomarkers were analyzed with elevations potentially suggesting acute kidney injury: (1) neutrophil gelatinase-associated lipocalin (NGAL), (2) kidney injury molecule-1, (3) albumin, and (4) nephrin. Fourteen unique patients were admitted for severe pain crises and were found to be representative of a larger SCA population. Urine samples were collected at the time of admission, during admission, and at follow-up after discharge. Exploratory analyses compared cohort values to the best available population values; individuals were also compared against themselves at various time points. Albumin was found to be moderately elevated for an individual during admission compared with follow-up ( P = 0.006, Hedge g : 0.67). Albumin was not found to be elevated compared with population values. Neutrophil gelatinase-associated lipocalin, kidney injury molecule-1, and nephrin were not found to be significantly elevated compared with population values or comparing admission to follow-up. Though albumin was found to be minimally elevated, further research should focus on alternative markers in efforts to further understand kidney disease in patients with SCA.

Humoral Response in Hemodialysis Patients Post-SARS-CoV-2 mRNA Vaccination: A Systematic Review of Literature

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has infected over 600 million individuals and caused nearly 7 million deaths worldwide (10 January 2023). Patients with renal disease undergoing hemodialysis are among those most adversely affected, with an increased predisposition to SARS-CoV-2 infection and death. This systematic review aimed to pool evidence assessing the humoral response of hemodialysis patients (HDP) post-mRNA SARS-CoV-2 vaccination. A systematic search of the literature was performed through MEDLINE, CINAHL, PubMed, EMBASE, and Web of Science databases, as well as medRxiv and bioRxiv preprint servers up to 10 January 2023. Cohort and case-control studies were included if they reported an immune response in one group of patients undergoing hemodialysis who received mRNA SARS-CoV-2 vaccination compared with another group of patients receiving the same vaccine but not on hemodialysis. The methodological quality was assessed using the Newcastle-Ottawa Scale. Meta-analysis was not deemed appropriate due to the high heterogeneity between studies. From the 120 studies identified, nine (n = 1969 participants) met the inclusion criteria. Most studies (n = 8/9, 88%) were of high or medium methodological quality (≥6/9 stars). The results revealed that HDP developed lower antibody levels across all timepoints post-vaccination when compared with controls. Patients with chronic kidney disease elicited the highest antibody immune response, followed by HDP and, lastly, kidney transplant recipients. Overall, post-vaccination antibody titers were comparatively lower than in the healthy population. Current results imply that robust vaccination strategies are needed to address waning immune responses in vulnerable populations.

Cytokeratin 18 cell death assays as biomarkers for quantification of apoptosis and necrosis in COVID-19: a prospective, observational study

BACKGROUND

The mechanism by which SARS-CoV-2 triggers cell damage and necrosis are yet to be fully elucidated. We sought to quantify epithelial cell death in patients with COVID-19, with an estimation of relative contributions of apoptosis and necrosis.

METHODS

Blood samples were collected prospectively from adult patients presenting to the emergency department. Circulating levels of caspase-cleaved (apoptosis) and total cytokeratin 18 (CK-18) (total cell death) were determined using M30 and M65 enzyme assays, respectively. Intact CK-18 (necrosis) was estimated by subtracting M30 levels from M65.

RESULTS

A total of 52 COVID-19 patients and 27 matched sick controls (with respiratory symptoms not due to COVID-19) were enrolled. Compared with sick controls, COVID-19 patients had higher levels of M65 (p = 0.046, total cell death) and M30 (p = 0.0079, apoptosis). Hospitalised COVID-19 patients had higher levels of M65 (p= 0.014) and intact CK-18 (p= 0.004, necrosis) than discharged patients. Intensive care unit (ICU)-admitted COVID-19 patients had higher levels of M65 (p= 0.004), M30 (p= 0.004) and intact CK-18 (p= 0.033) than hospitalised non-ICU admitted patients. In multivariable logistic regression, elevated levels of M65, M30 and intact CK-18 were associated with increased odds of ICU admission (OR=22.05, p=0.014, OR=19.71, p=0.012 and OR=14.12, p=0.016, respectively).

CONCLUSION

Necrosis appears to be the main driver of hospitalisation, whereas apoptosis and necrosis appear to drive ICU admission. Elevated levels CK-18 levels are independent predictors of severe disease, and could be useful for risk stratification of COVID-19 patients and in assessment of therapeutic efficacy in early-phase COVID-19 clinical trials.

A case of treatment-resistant membranous nephropathy associated with graft versus host disease successfully treated with daratumumab

BACKGROUND

Membranous nephropathy (MN) is the most common cause of glomerulopathy after hematopoietic cell transplantation (HCT), most often occurring in the setting of graft versus host disease (GVHD). Twenty percent of patients will fail to respond to standard therapy and may progress to end stage renal disease. Here we present the case of a pediatric patient who developed chronic oral GVHD more than one-year post-HCT, who subsequently developed nephrotic syndrome (anasarca, nephrotic range proteinuria, hypoalbuminemia) and had a renal biopsy consistent with MN. Treated with ibrutinib for her GVHD, and steroids, tacrolimus, and rituximab for her MN, she failed to achieve even partial remission of her kidney disease after 8 months. Due to steroid toxicity and 0% CD19 cells on lymphocyte subpopulation flow cytometry, the decision was made to trial plasma cell depletion therapy with daratumumab.

METHOD

She received three doses of daratumumab at weeks 1, 4, and 17.

RESULTS

Her nephrotic syndrome resolved and her serum albumin was greater than 3.0 gm/dl by week 10. She was weaned off of both steroids and tacrolimus by week 16, at which time she had near-complete remission of her renal disease.

CONCLUSION

Daratumumab may be an important, novel therapeutic option for post-HCT MN patients who are not responsive to standard therapies.

Multiparametric quantitative renal MRI in children and young adults: comparison between healthy individuals and patients with chronic kidney disease

PURPOSE

Multiparametric quantitative renal MRI may provide noninvasive radiologic biomarkers of chronic kidney disease (CKD) based on investigations in animal models and adults. We aimed to (1) obtain normative multiparametric quantitative MRI data from the kidneys of healthy children and young adults, (2) compare MRI measurements between healthy control participants and patients with CKD, and (3) determine if MRI measurements correlate with clinical and laboratory data as well as histology.

METHODS

This was a prospective, case-control study of 20 healthy controls and 12 CKD patients who underwent percutaneous renal biopsy ranging from 12 to 23 years of age between October 2018 and March 2020. Kidney function was documented and pathology assessed for fibrosis/inflammation. Utilizing a field strength of 1.5T, we examined renal T1, T2, and T2* relaxation mapping, MR elastography (MRE), and diffusion-weighted imaging (DWI). A single analyst made all manual measurements for quantitative MRI pulse sequences. Independent measurements from cortex, medulla, and whole kidney were obtained by drawing regions of interest on single slices from the upper, mid, and lower kidney. A weighted average was calculated for each kidney; if two kidneys, the right and left were averaged. Continuous variables were compared with Mann-Whitney U test; bivariate relationships were assessed using Spearman rank-order correlation.

RESULTS

Median estimated glomerular filtration rate (eGFR) was 112.3 ml/min/1.73 m² in controls (n = 20, 10 females) and 55.0 ml/min/m² in CKD patients (n = 12, 2 females) (p < 0.0001). Whole kidney (1333 vs. 1291 ms; p = 0.018) and cortical (1212 vs 1137 ms; p < 0.0001) T1 values were higher in CKD patients. Cortical T1 values correlated with eGFR (rho = - 0.62; p = 0.0003) and cystatin C (rho = 0.58; p = 0.0007). Whole kidney (1.87 vs. 2.02 10^-3 mm²/s; p = 0.007), cortical (1.89 vs. 2.04 10^-3 mm²/s; p = 0.008), and medullary (1.87 vs. 1.98 10^-3 mm²/s; p = 0.0095) DWI apparent diffusion coefficients (ADC) were lower in CKD patients. Whole kidney ADC correlated with eGFR (rho = 0.45; p = 0.012) and cystatin C (rho = - 0.46; p = 0.009). Cortical histologic inflammation correlated with DWI ADC (rho = - 0.71; p = 0.011).

CONCLUSION

Renal T1 relaxation and DWI ADC measurements differ between pediatric healthy controls and CKD patients, correlate with laboratory markers of CKD, and may have histologic correlates.

Complement Levels at Admission Reflecting Progression to Severe Acute Kidney Injury (AKI) in Coronavirus Disease 2019 (COVID-19): A Multicenter Prospective Cohort Study

Background

Dysregulation of complement system is thought to be a major player in development of multi-organ damage and adverse outcomes in patients with coronavirus disease 2019 (COVID-19). This study aimed to examine associations between complement system activity and development of severe acute kidney injury (AKI) among hospitalized COVID-19 patients.

Materials and Methods

In this multicenter, international study, complement as well as inflammatory and thrombotic parameters were analyzed in COVID-19 patients requiring hospitalization at one US and two Hungarian centers. The primary endpoint was development of severe AKI defined by KDIGO stage 2+3 criteria, while the secondary endpoint was need for renal replacement therapy (RRT). Complement markers with significant associations with endpoints were then correlated with a panel of inflammatory and thrombotic biomarkers and assessed for independent association with outcome measures using logistic regression.

Results

A total of 131 hospitalized COVID-19 patients (median age 66 [IQR, 54–75] years; 54.2% males) were enrolled, 33 from the US, and 98 from Hungary. There was a greater prevalence of complement over-activation and consumption in those who developed severe AKI and need for RRT during hospitalization. C3a/C3 ratio was increased in groups developing severe AKI (3.29 vs. 1.71; p < 0.001) and requiring RRT (3.42 vs. 1.79; p < 0.001) in each cohort. Decrease in alternative and classical pathway activity, and consumption of C4 below reference range, as well as elevation of complement activation marker C3a above the normal was more common in patients progressing to severe AKI. In the Hungarian cohort, each standard deviation increase in C3a (SD = 210.1) was independently associated with 89.7% increased odds of developing severe AKI (95% CI, 7.6–234.5%). Complement was extensively correlated with an array of inflammatory biomarkers and a prothrombotic state.

Conclusion

Consumption and dysregulation of complement system is associated with development of severe AKI in COVID-19 patients and could represent a promising therapeutic target for reducing thrombotic microangiopathy in SARS-CoV-2 infection.

The Predictive Value of Serum ACE2 and TMPRSS2 Concentrations in Patients with COVID-19-A Prospective Pilot Study

One of the major challenges for healthcare systems during the Coronavirus-2019 (COVID-19) pandemic was the inability to successfully predict which patients would require mechanical ventilation (MV). Angiotensin-Converting Enzyme 2 (ACE2) and TransMembrane Protease Serine S1 member 2 (TMPRSS2) are enzymes that play crucial roles in SARS-CoV-2 entry into human host cells. However, their predictive value as biomarkers for risk stratification for respiratory deterioration requiring MV has not yet been evaluated. We aimed to evaluate whether serum ACE2 and TMPRSS2 levels are associated with adverse outcomes in COVID-19, and specifically the need for MV. COVID-19 patients admitted to an Israeli tertiary medical center between March--November 2020, were included. Serum samples were obtained shortly after admission (day 0) and again following one week of admission (day 7). ACE2 and TMPRSS2 concentrations were measured with ELISA. Of 72 patients included, 30 (41.6%) ultimately required MV. Serum ACE2 concentrations >7.8 ng/mL at admission were significantly associated with the need for MV (p = 0.036), inotropic support, and renal replacement therapy. In multivariate logistic regression analysis, elevated ACE2 at admission was associated with the need for MV (OR = 7.49; p = 0.014). To conclude, elevated serum ACE2 concentration early in COVID-19 illness correlates with respiratory failure necessitating mechanical ventilation. We suggest that measuring serum ACE2 at admission may be useful for predicting the risk of severe disease.

Early prediction of COVID-19-associated Acute Kidney Injury: Are serum NGAL and serum Cystatin C levels better than serum creatinine?

Background

Coronavirus disease-2019 (COVID-19) is associated with a high risk of acute kidney injury (AKI), often requiring renal replacement therapy (RRT). Serum Cystatin C (sCysC) and serum Neutrophil Gelatinase-Associated Lipocalin (sNGAL) are emerging biomarkers for kidney injury, and were suggested to be superior to serum creatinine (sCr) in several clinical settings. Moreover, elevated sCysC is associated with disease severity and mortality in COVID-19. We aimed to assess the utility of sCysC and sNGAL for predicting COVID-19-associated AKI, need for RRT, and need for intensive care unit (ICU) admission, when measured at presentation to the emergency department (ED).

Methods

Patients presenting to the ED with laboratory-confirmed COVID-19 were included. The primary outcome was development of COVID-19-associated AKI, while the secondary outcomes were need for RRT and ICU admission.

Results

Among 52 COVID-19 patients, 22 (42.3%) developed AKI with 8/22 (36.4%) requiring RRT. Both sCr and sCysC demonstrated excellent performance for predicting AKI (AUC, 0.86 and 0.87, respectively) and need for RRT (AUC, 0.94 and 0.95, respectively). sNGAL displayed acceptable performance for predicting AKI (AUC, 0.81) and need for RRT (AUC, 0.87).

Conclusions

SCr and sCysC measured at ED presentation are both highly accurate predictors of AKI and need for RRT, whereas sNGAL demonstrated adequate diagnostic performance. While sCyC was previously shown to be superior to sCr as a diagnostic biomarker of kidney injury in certain etiologies, our findings demonstrate that sCr is comparable to sCyC in the context of predicting COVID-19-associated AKI. Given the high sensitivity of these biomarkers for predicting the need for RRT, and as sCysC is associated with mortality in COVID-19 patients, we recommend their measurement for enabling risk stratification and early intervention.

Anti-Endothelial Cell Antibodies are not frequently elevated in hospitalized patients with COVID-19

n/a.

Case Report: Atypical HUS Presenting With Acute Rhabdomyolysis Highlights the Need for Individualized Eculizumab Dosing

BACKGROUND

Atypical hemolytic uremic syndrome (aHUS) is an ultra-rare orphan disease caused by dysregulated complement activation resulting in thrombotic microangiopathy. Although complement-mediated endothelial injury predominantly affects the renal microvasculature, extra-renal manifestations are present in a significant proportion of patients. While eculizumab has significantly improved the morbidity and mortality of this rare disease, optimizing therapeutic regimens of this highly expensive drug remains an active area of research in the treatment of aHUS.

CASE PRESENTATION

This report describes the case of a previously healthy 4 year-old male who presented with rhabdomyolysis preceding the development of aHUS with anuric kidney injury requiring dialysis. Clinical stabilization required increased and more frequent eculizumab doses compared with the standardized weight-based guidelines. In the maintenance phase of his disease, pharmacokinetic analysis indicated adequate eculizumab levels could be maintained with an individualized dosing regimen every 3 weeks, as opposed to standard 2 week dosing, confirmed in this patient over a 4 year follow up period. Cost analyses show that weight-based maintenance dosing costs $312,000 per year, while extending the dosing interval to every 3 weeks would cost $208,000, a savings of $104,000 per year, relative to the cost of $72,000 from more frequent eculizumab dosing during his initial hospitalization to suppress his acute disease.

CONCLUSION

This case exemplifies the potential of severe, multisystem involvement of aHUS presenting with extra-renal manifestations, including rhabdomyolysis as in this case, and highlights the possibility for improved clinical outcomes and higher value care with individualized eculizumab dosing in patients over the course of their disease.

Anti-Endothelial Cell Antibodies are not frequently elevated in hospitalized patients with COVID-19

COVID-19 is now established to be associated with a thrombotic phenomenon, now called COVID-19 associated coagulopathy (CAC). Anti-Endothelial Cell Antibodies (AECA) are a heterogenous group of autoantibodies targeting various endothelial cell antigens or antigens adhering to endothelial cells, They are commonly observed in a variety of auto-immune and rheumatologic conditions, and were observed in patients with the severe acute respiratory syndrome (SARS) in 2005. We aimed to assess AECA status in patients with COVID-19 and their potential contributing role to endothelial injury and CAC. AECA identification was a relatively infrequent finding in COVID-19 patients on admission, and their presence, albeit in only 2/33 patients, was not associated with disease severity. However, as the autoantibodies were only measured at admission, we cannot exclude the possibility of pathogenic AECA developing later in the course of diseaseFurther studies using additional methods are needed to evaluate the presence and potential pathogenic role of AECA in later stages of COVID-19.

Complement levels at admission as a reflection of coronavirus disease 2019 (COVID-19) severity state

Complement system hyperactivation has been proposed as a potential driver of adverse outcomes in severe acute respiratory syndrome coronavirus 2 infected patients, given prior research of complement deposits found in tissue and blood samples, as well as evidence of clinical improvement with anticomplement therapy. Its role in augmenting thrombotic microangiopathy mediated organ damage has also been implicated in coronavirus disease 2019 (COVID‐19). This study aimed to examine associations between complement parameters and progression to severe COVID‐19 illness, as well as correlations with other systems. Blood samples of COVID‐19 patients presenting to the emergency department (ED) were analyzed for a wide panel of complement and inflammatory biomarkers. The primary outcome was COVID‐19 severity at index ED visit, while the secondary outcome was peak disease severity over the course of illness. Fifty‐two COVID‐19 patients were enrolled. C3a (p = 0.018), C3a/C3 ratio (p = 0.002), and sC5b‐9/C3 ratio (p = 0.021) were significantly elevated in with severe disease at ED presentation. Over the course of illness, C3a (p = 0.028) and C3a/C3 ratio (p = 0.003) were highest in the moderate severity group. In multivariate regression controlled for confounders, complement hyperactivation failed to predict progression to severe disease. C3a, C3a/C3 ratio, and sC5b‐9/C3 ratio were correlated positively with numerous inflammatory biomarkers, fibrinogen, and VWF:Ag, and negatively with plasminogen and ADAMTS13 activity. We found evidence of complement hyperactivation in COVID‐19, associated with hyperinflammation and thrombotic microangiopathy. Complement inhibition should be further investigated for potential benefit in patients displaying a hyperinflammatory and microangiopathic phenotype.

Serum ACE activity and plasma ACE concentration in patients with SARS-CoV-2 infection

Significant controversy has arisen over the role of the renin-angiotensin-aldosterone system (RAAS) in COVID-19 pathophysiology. In this prospective, observational study, we evaluated plasma angiotensin converting enzyme (ACE) concentration and serum ACE activity in 52 adults with laboratory-confirmed SARS-CoV-2 infection and 27 non-COVID-19 sick controls. No significant differences were observed in ACE activity in COVID-19 patients versus non-COVID-19 sick controls (41.1 [interquartile range (IQR): 23.0–55.2] vs. 42.9 [IQR 13.6–74.2] U/L, p = .649, respectively). Similarly, no differences were observed in ACE concentration in COVID-19 patients versus non-COVID-19 sick controls (108.4 [IQR: 95.8–142.2] vs. 133.8 [IQR: 100.2–173.7] μg/L, p = .059, respectively). Neither ACE activity (p = .751), nor ACE concentration (p = .283) was associated with COVID-19 severity. Moreover, neither ACE activity, nor ACE concentration was correlated with any inflammatory biomarkers.

Alterations in the lipid profile associate with a dysregulated inflammatory, prothrombotic, anti-fibrinolytic state and development of severe acute kidney injury in coronavirus disease 2019 (COVID-19): A study from Cincinnati, USA

BACKGROUND AND AIMS

Reduction of atherogenic lipoproteins is often the ultimate goal of nutritional interventions, however this is complicated given that hypolipidemia is frequently observed in coronavirus disease 2019 (COVID-19) patients. We aimed to explore the association of hypolipidemia with patient outcomes in terms of immunothrombosis and multiorgan injury, focusing on specialized apolipoproteins apo A1 and apo B.

METHODS

Lipid profiles of 50 COVID-19 patients and 30 sick controls presenting to the Emergency Department (ED) were measured in this prospective observational study. The primary outcome was development of severe acute kidney injury (AKI). Need for hospitalization and ICU admission were secondary outcomes. Lipoproteins were analyzed for independent association with serum creatinine (SCr) increase ratio and correlated with a wide panel of biomarkers.

RESULTS

COVID-19 cohort had significantly lower apo A1 (p = 0.006), and higher apo B/apo A1 ratio (p = 0.041). Patients developing severe AKI had significantly lower LDL-C (p = 0.021). Apo B/apo A1 was associated with 2.25-fold decrease in serum SCr increase ratio, while LDL-C with a 1.5% decrease. Hypolipidemia correlated with low plasminogen, ADAMTS13 activity/VWF:Ag, and high inflammatory biomarkers (CRP, IL-6, IL-8, IL-10), plasminogen activator inhibitor-1 (PAI-1), ED creatinine, and SCr increase ratio.

CONCLUSION

Although favored in dietetics, findings of a low LDL-C in COVID-19 patients should be alarming in light of our observations. Low apo B/apo A1 ratio and LDL-C are predictive of renal deterioration in COVID-19 patients, and low LDL-C in particular may potentially serve to indicate COVID-19 related AKI driven by disrupted fibrinolysis and a secondary thrombotic microangiopathy-like process.

Alpha 1 Antitrypsin is an Inhibitor of the SARS-CoV-2-Priming Protease TMPRSS2

BACKGROUND

Host proteases have been suggested to be crucial for dissemination of MERS, SARS-CoV, and SARS-CoV-2 coronaviruses, but the relative contribution of membrane versus intracellular proteases remains controversial. Transmembrane serine protease 2 (TMPRSS2) is regarded as one of the main proteases implicated in the coronavirus S protein priming, an important step for binding of the S protein to the angiotensin-converting enzyme 2 (ACE2) receptor before cell entry.

METHODS

We developed a cell-based assay to identify TMPRSS2 inhibitors. Inhibitory activity was established in SARS-CoV-2 viral load systems.

RESULTS

We identified the human extracellular serine protease inhibitor (serpin) alpha 1 anti-trypsin (A1AT) as a novel TMPRSS2 inhibitor. Structural modeling revealed that A1AT docked to an extracellular domain of TMPRSS2 in a conformation that is suitable for catalysis, resembling similar serine protease inhibitor complexes. Inhibitory activity of A1AT was established in a SARS-CoV-2 viral load system. Notably, plasma A1AT levels were associated with COVID-19 disease severity.

CONCLUSIONS

Our data support the key role of extracellular serine proteases in SARS CoV-2 infections and indicate that treatment with serpins, particularly the FDA-approved drug A1AT, may be effective in limiting SARS-CoV-2 dissemination by affecting the surface of the host cells.

Tolerance of dinutuximab therapy for treatment of high-risk neuroblastoma in two patients with end-stage renal disease on dialysis

Autologous hematopoietic cell transplant (aHCT) has a significant survival advantage in patients with high-risk (HR) neuroblastoma. Transplant-associated thrombotic microangiopathy (TA-TMA) is a serious complication and may result in chronic renal disease leading to delay in subsequent posttransplant therapy and limitations of treatment options. Dinutuximab represents an important therapeutic advance in the treatment of pediatric HR neuroblastoma, but historically has not been administered in patients with GFR < 60 mL/m² /min. Here, we present the safe outcome of dinutuximab administration while on renal replacement therapy in two cases of HR neuroblastoma with end-stage renal disease secondary to TA-TMA.

GFR Estimation After Cystatin C Reference Material Change

Introduction

Glomerular filtration rate (GFR) is routinely estimated with cystatin C. In June 2010, the International Federation of Clinical Chemistry (IFCC) released a certified cystatin C reference material (ERM-DA471/IFCC), and new cystatin C glomerular filtration rate estimation (eGFR) equations were developed with the IFCC standard. Early in 2018, Siemens discontinued their nonstandardized cystatin C reagent kits and replaced them with IFCC-calibrated kits in the US market. The aim of the current study was to assess the effect of IFCC calibration on cystatin C values and corresponding GFR estimations.

Methods

Cystatin C concentration was measured in 81 pediatric patients using a plasma sample from their nuclear GFR measurement with 99mTc-diethylenetriaminepentaaccetic acid. Calibration curves were generated using Siemens nonstandardized and IFCC-standardized kits to measure paired cystatin C concentrations in each sample. GFR-estimating equations using pre-IFCC and IFCC cystatin C values were compared using Bland-Altman analyses.

Results

The IFCC-standardized assay resulted in a mean increase in the measured cystatin C value of 24%. Estimating equations consistently overestimated GFR prior to IFCC standardization. Following incorporation of the IFCC standard, the Full Age Spectrum equation demonstrated the best overall performance, whereas the Chronic Kidney Disease in Children (CKiD) equation was more accurate in children with decreased GFR.

Conclusion

Incorporation of the IFCC standard significantly increased cystatin C values and affected the performance of GFR estimating equations. Clinical laboratories and providers may need to update the equation used for cystatin C-based estimation of GFR following adoption of the IFCC reference standard.

ADAMTS13 activity to von Willebrand factor antigen ratio predicts acute kidney injury in patients with COVID-19: Evidence of SARS-CoV-2 induced secondary thrombotic microangiopathy

Introduction

Severe COVID‐19 is often compounded by a prothrombotic state that is associated with poor outcomes. In this investigation, we aimed to evaluate ADAMTS13 activity, von Willebrand factor level (VWF:Ag), and the corresponding ADAMTS13 activity/VWF:Ag ratio, in patients with COVID‐19 and for associations with disease progression and acute kidney injury (AKI).

Methods

Patients presenting to the emergency department (ED) with COVID‐19 were enrolled in this prospective, observational study. ADAMTS13 activity and VWF:Ag were measured at index ED visit. The primary endpoint was severe AKI defined by KDIGO stage 2 + 3 criteria, while the secondary endpoint was peak 30‐day COVID‐19 severity.

Results

A total of 52 adult COVID‐19 patients were enrolled. Overall, we observed that 23.1% of the cohort had a relative deficiency in ADAMTS13 activity, while 80.8% had elevated VWF:Ag. The ADAMTS13 activity/VWF:Ag ratio was significantly lower in patients with severe AKI (P = .002) and those who developed the severe form of COVID‐19 (P = .020). The ADAMTS13 activity/VWF:Ag ratio was negatively correlated with age (P < .001) and LDH (P < .001), while positively correlated with hemoglobin (P = .041). After controlling for confounders, a one‐unit increase in ADAMTS13/VWF:Ag ratio was associated with 20% decreased odds of severe AKI.

Conclusion

A low ADAMTS13 activity:VWF:Ag ratio at ED presentation is associated with progression to severe COVID‐19 disease and severe AKI, with a pattern suggestive of a secondary microangiopathy. Further interventional studies should be conducted to assess the restoration of ADAMTS13:VWF:Ag ratio in hospitalized patients with COVID‐19.

The anti-inflammatory cytokine response characterized by elevated interleukin-10 is a stronger predictor of severe disease and poor outcomes than the pro-inflammatory cytokine response in coronavirus disease 2019 (COVID-19)

OBJECTIVES

Severe coronavirus disease 2019 (COVID-19) is associated with a dysregulated immune state. While research has focused on the hyperinflammation, little research has been performed on the compensatory anti-inflammatory response. The aim of this study was to evaluate the anti-inflammatory cytokine response to COVID-19, by assessing interleukin-10 (IL-10) and IL-10/lymphocyte count ratio and their association with outcomes.

METHODS

Adult patients presenting to the emergency department (ED) with laboratory-confirmed COVID-19 were recruited. The primary endpoint was maximum COVID-19 severity within 30 days of index ED visit.

RESULTS

A total of 52 COVID-19 patients were enrolled. IL-10 and IL-10/lymphocyte count were significantly higher in patients with severe disease (p<0.05), as well as in those who developed severe acute kidney injury (AKI) and new positive bacterial cultures (all p≤0.01). In multivariable analysis, a one-unit increase in IL-10 and IL-10/lymphocyte count were associated with 42% (p=0.031) and 32% (p=0.013) increased odds, respectively, of severe COVID-19. When standardized to a one-unit standard deviations scale, an increase in the IL-10 was a stronger predictor of maximum 30-day severity and severe AKI than increases in IL-6 or IL-8.

CONCLUSIONS

The hyperinflammatory response to COVID-19 is accompanied by a simultaneous anti-inflammatory response, which is associated with poor outcomes and may increase the risk of new positive bacterial cultures. IL-10 and IL-10/lymphocyte count at ED presentation were independent predictors of COVID-19 severity. Moreover, elevated IL-10 was more strongly associated with outcomes than pro-inflammatory IL-6 or IL-8. The anti-inflammatory response in COVID-19 requires further investigation to enable more precise immunomodulatory therapy against SARS-CoV-2.

Alpha 1 Antitrypsin is an Inhibitor of the SARS-CoV-2-Priming Protease TMPRSS2

Host proteases have been suggested to be crucial for dissemination of MERS, SARS-CoV, and SARS-CoV-2 coronaviruses, but the relative contribution of membrane versus intracellular proteases remains controversial. Transmembrane serine protease 2 (TMPRSS2) is regarded as one of the main proteases implicated in the coronavirus S protein priming, an important step for binding of the S protein to the angiotensin-converting enzyme 2 (ACE2) receptor before cell entry. The main cellular location where the SARS-CoV-2 S protein priming occurs remains debatable, therefore hampering the development of targeted treatments. Herein, we identified the human extracellular serine protease inhibitor (serpin) alpha 1 antitrypsin (A1AT) as a novel TMPRSS2 inhibitor. Structural modeling revealed that A1AT docked to an extracellular domain of TMPRSS2 in a conformation that is suitable for catalysis, resembling similar serine protease-inhibitor complexes. Inhibitory activity of A1AT was established in a SARS-CoV-2 viral load system. Notably, plasma A1AT levels were associated with COVID-19 disease severity. Our data support the key role of extracellular serine proteases in SARS-CoV-2 infections and indicate that treatment with serpins, particularly the FDA-approved drug A1AT, may be effective in limiting SARS-CoV-2 dissemination by affecting the surface of the host cells.

SUMMARY

Delivery of extracellular serine protease inhibitors (serpins) such as A1AT has the capacity to reduce SARS-CoV-2 dissemination by binding and inhibiting extracellular proteases on the host cells, thus, inhibiting the first step in SARS-CoV-2 cell cycle (i.e. cell entry).

Laboratory abnormalities in children with mild and severe coronavirus disease 2019 (COVID-19): A pooled analysis and review

Limited data exists to-date on the laboratory findings in children with COVID-19, warranting the conduction of this study, in which we pool the currently available literature data on the laboratory findings seen in children with mild and severe COVID-19. Following an extensive literature search, we identified 24 eligible studies, including a total of 624 pediatric cases with laboratory-confirmed COVID-19, which report data on 27 different biomarkers. We then performed a meta-analysis to calculate the pooled prevalence estimates (PPE) for these laboratory abnormalities in mild COVID-19. As data was too limited for children with severe COVID-19 to allow pooling, results were presented descriptively in a summary of findings table. Our data show an inconsistent pattern of change in the leukocyte index of mild and severe cases of COVID-19 in children. Specifically, changes in leukocyte counts were only observed in 32% of the mild pediatric cases (PPE: 13% increase, 19% decrease). In mild disease, creatine kinase-MB (CK-MB) was frequently elevated, with a PPE of 33%. In severe disease, c-reactive protein (CRP), procalcitonin (PCT), and lactate dehydrogenase (LDH) were frequently elevated. Based on data obtained from early COVID-19 studies, leukocyte indices in children appear inconsistent, differing from those reported in adults that highlight specific leukocyte trends. This brings into question the utility and reliability of such parameters in monitoring disease severity in the pediatric population. Instead, we suggest physicians to serially monitor CRP, PCT, and LDH to track the course of illness in hospitalized children. Finally, elevated CK-MB in mild pediatric COVID-19 cases is indicative of possible cardiac injury. This highlights the importance of monitoring cardiac biomarkers in hospitalized patients and the need for further investigation of markers such as cardiac troponin in future studies.

Reduction in Nephrotoxic Antimicrobial Exposure Decreases Associated Acute Kidney Injury in Pediatric Hematopoietic Stem Cell Transplant Patients

Exposure to nephrotoxic medications is a common risk factor for acute kidney injury (AKI) in pediatric stem cell transplantation (SCT). We hypothesized that reducing nephrotoxic antimicrobial exposure for SCT patients would be associated with lower nephrotoxin-associated AKI (NTMx-AKI) rates and no increase in infection treatment failures. We conducted a prospective cohort analysis of all inpatient SCT patients at Cincinnati Children's Hospital Medical Center between January 2014 and December 2017. In January 2016, first line fever coverage was changed from piperacillin-tazobactam to cefepime, acknowledging that the change resulted in a loss of enterococcal coverage, and the duration of antimicrobial exposures was limited, specifically including vancomycin. We collected data using prospective NTMx-AKI and antimicrobial utilization monitoring platforms within the electronic health record. AKI days and severity were extracted for patients exposed to 3+ nephrotoxins, 3+ days of IV aminoglycosides, or 3+ days of IV vancomycin. AKI was identified using KDIGO serum creatinine criteria. We assessed rates of nephrotoxin exposure and NTMx-AKI in all SCT inpatients for 2 years pre- and post-intervention. Data were grouped and analyzed by calendar month, normalized to a denominator of 1000 patient-days. Statistical process control methods were used to monitor adherence to the intervention and identify changes in mean rate of nephrotoxin exposure and NTMx-AKI. Infection rates, alternate antimicrobial usage rates, and the fraction of repeat positive cultures were used to identify treatment failures. PTZ usage decreased from 196 to 33 days/1000 patient days, cefepime usage increased from 62 to 290 days/1000 patient days, and vancomycin usage decreased from 62 to 41 days/1000 patient days. High nephrotoxin exposure decreased by 33% (143 to 96 days/1000 patient days), and NTMx-AKI decreased by 74% (24 to 6 days/1000 patient days). Rates of all KDIGO stages of NTMx-AKI decreased ≥50% after the intervention. Stage 3, the most severe, decreased by >80%. The fraction of repeat positive cultures remained stable between the two eras at .1 (standard deviation 0.21) and .07 (standard deviation 0.17), respectively. There were no increases in infection rates, alternate antimicrobial usage rates, or treatment failures. Reduction of nephrotoxic antimicrobial exposure can decrease the amount and severity of NTMx-AKI in SCT patients without an increase in treatment failures.

A novel strategy for identifying early acute kidney injury in pediatric hematopoietic stem cell transplantation

Acute kidney injury (AKI) is a common complication in pediatric hematopoietic stem cell transplantation (HSCT). Serum creatinine is an imprecise biomarker of AKI. We hypothesized that combining creatinine with serum cystatin C (cysC) and urinary neutrophil gelatinase-associated lipocalin (NGAL) more effectively characterizes AKI during the first 28 days of HSCT and better identifies patients at risk of adverse outcomes than creatinine alone. We prospectively assessed the type and severity of AKI in 80 consecutive allogeneic HSCT patients using weekly creatinine, cysC, and NGAL. We combined the biomarkers to define 7 Composite Types of AKI, including All Positive AKI (simultaneously detected creatinine, cysC, and NGAL AKI). Outcomes included renal replacement therapy and transplant-related mortality. In all, 75% of patients had AKI by at least one measure; 33% developed >1 type of AKI. Mild AKI often preceded Severe AKI. Patients with creatinine or NGAL AKI that were Severe or Repeated tended to have worse outcomes. The five patients with All Positive AKI had the highest rates of morbidity and mortality. AKI evaluation with creatinine, cysC, and NGAL provides a comprehensive profile of early AKI and narrowly identifies patients at highest risk of adverse outcomes, providing opportunities for early, impactful intervention.