Changes in Numbers of Glomerular Macrophages Between Two Consecutive Biopsies and the Association With Renal Transplant Graft Survival.

BACKGROUND: Macrophages are involved in kidney transplants. The aim of the study was to investigate if changes exist in the levels of glomerular macrophage index (GMI) between two consecutive kidney transplant biopsies, and if so to determine their potential impact on graft survival. METHODS: Two consecutive biopsies were performed on the same renal graft in 623 patients. GMI was categorized into three GMI classes: ≤1.8 Low, 1.9-4.5 Medium, and ≥4.6 High. This division yielded nine possible switches between the first and second biopsies (Low-Low, Low-Medium, etc.). Cox-regressions were used and hazard ratios (HR) with 95% confidence interval (CI) are presented. RESULTS: The worst graft survival was observed in the High-High group, and the best graft survival was observed in the Low-Low and High-Low groups. Compared to the High-High group, a reduction of risk was observed in nearly all other decreasing groups (reductions between 65% and 80% of graft loss). After adjustment for covariates, the risk for graft-loss was lower in the Low-Low (HR = 0.24, CI 0.13-0.46), Low-Medium (HR = 0.25, CI 0.11-0.55), Medium-Low (HR = 0.29, CI 0.11-0.77), and the High-Low GMI (HR = 0.31, CI 0.10-0.98) groups compared to the High-High group as the reference. CONCLUSIONS: GMI may change dynamically, and the latest finding is of most prognostic importance. GMI should be considered in all evaluations of biopsy findings since high or increasing GMI levels are associated with shorter graft survival. Future studies need to consider therapeutic strategies to lower or maintain a low GMI. A high GMI besides a vague histological finding should be considered as a warning sign requiring more frequent clinical follow up.

Dynamics of urine proteomics biomarker and disease progression in patients with IgA nephropathy.

BACKGROUND: Immunoglobulin A nephropathy (IgAN) frequently leads to kidney failure. The urinary proteomics-based classifier IgAN237 may predict disease progression at the time of kidney biopsy. We studied whether IgAN237 also predicts progression later in the course of IgAN. METHODS: Urine from patients with biopsy-proven IgAN was analyzed using capillary electrophoresis-mass spectrometry at baseline (IgAN237-1, n = 103) and at follow-up (IgAN237-2, n = 89). Patients were categorized as "non-progressors" (IgAN237 ≤0.38) and "progressors" (IgAN237 >0.38). Estimated glomerular filtration rate (eGFR) and urinary albumin-creatinine ratio slopes were calculated. RESULTS: Median age at biopsy was 44 years, interval between biopsy and IgAN237-1 was 65 months and interval between IgAN237-1 and IgAN237-2 was 258 days (interquartile range 71-531). IgAN237-1 and IgAN237-2 values did not differ significantly and were correlated (rho = 0.44, P < .001). Twenty-eight percent and 26% of patients were progressors based on IgAN237-1 and IgAN237-2, respectively. IgAN237 inversely correlated with chronic eGFR slopes (rho = -0.278, P = .02 for score-1; rho = -0.409, P = .002 for score-2) and with ±180 days eGFR slopes (rho = -0.31, P = .009 and rho = -0.439, P = .001, respectively). The ±180 days eGFR slopes were worse for progressors than for non-progressors (median -5.98 versus -1.22 mL/min/1.73 m2 per year for IgAN237-1, P < .001; -3.02 vs 1.08 mL/min/1.73 m2 per year for IgAN237-2, P = .0047). In multiple regression analysis baseline progressor/non-progressor according to IgAN237 was an independent predictor of eGFR180days-slope (P = .001). CONCLUSION: The urinary IgAN237 classifier represents a risk stratification tool in IgAN also later in the course of the dynamic disease. It may guide patient management in an individualized manner.

Sex-specific time trends of long-term graft survival after kidney transplantation - a registry-based study.

BACKGROUND: Sex-specific trends over time with respect to kidney graft survival have scarcely been described in earlier studies. The present study aimed to examine whether kidney graft survival differs between women and men over time. METHODS: This study was based on prospectively collected data extracted from a quality registry including all kidney transplant patients between January 1965 and September 2017 at the transplantation center of a university hospital in Sweden. The transplantation center serves a population of approximately 3.5 million inhabitants. Only the first graft for each patient was included in the study resulting in 4698 transplantations from unique patients (37% women, 63% men). Patients were followed-up until graft failure, death, or the end of the study. Death-censored graft survival analysis after kidney transplantation (KT) was performed using Kaplan-Meier analysis with log-rank test, and analysis adjusted for confounders was performed using multivariable Cox regression analysis. RESULTS: Median age at transplantation was 48 years (quartiles 36-57 years) and was similar for women and men. Graft survival was analyzed separately in four transplantation periods that represented various immunosuppressive regimes (1965-1985, 1986-1995, 1996-2005, and 2006-2017). Sex differences in graft survival varied over time (sex-by-period interaction, p = 0.026). During the three first periods, there were no significant sex differences in graft survival. However, during the last period, women had shorter graft survival (p = 0.022, hazard ratio (HR) 1.71, 95% confidence interval (CI) 1.1-2.7, adjusted for covariates). Biopsy-proven rejections were more common in women. CONCLUSIONS: In this registry-based study, women had shorter graft survival than men during the last observation period (years 2006-2017).

Enzymatic removal of sialic acid enables iCIEF stability monitoring of charge variants of a highly sialylated bispecific antibody.

Antibody-based therapeutic proteins have highly complex molecular structures. The final therapeutic protein product may contain a wide range of charge variants. Accurate analysis of this charge variant composition is critical to determine manufacturing process consistency and protein stability and ultimately helps to ensure that patients receive a safe and efficacious product. Here, a highly sialylated bispecific antibody (bsAb-1) challenged the ability to monitor stability by imaged capillary isoelectric focusing (iCIEF). This challenge was overcome by optimization of the iCIEF master mix buffer (adjustment of urea concentration, addition of l-arginine) and enzymatic removal of sialic acid. The method was qualified by assessing linearity, precision, LOD, LOQ, accuracy, and robustness in accordance with ICH guidance. Main species loss detectability increased up to approximately fivefold compared to the iCIEF method without desialylation when monitoring changes in stressed samples. Importantly, the results of the iCIEF method with desialylation correlated with results obtained through LC-MS tryptic peptide mapping and enabled analysis of formulation development stability samples. Finally, this analytical method shows the potential to assess low-concentration formulation development samples down to a sample concentration of 0.1 mg/ml.

Glomerular macrophage index (GMI) in kidney transplant biopsies is associated with graft outcome.

BACKGROUND: Macrophages in renal transplants have been shown to participate in antibody-mediated rejection and are associated with impaired renal function. We calculated the glomerular macrophage index (GMI) in a large transplant biopsy cohort, studied its quantity in different diagnostic groups, to clarify its possible impact on graft survival. METHODS: GMI, defined as the mean number of macrophages in 10 glomeruli, was prospectively quantified in 1440 renal transplant biopsies over a 10-year period. The main histopathological diagnoses were grouped into eight disease entities, and GMI was compared to normal transplant biopsies as the reference group. The impact of GMI on graft survival was analyzed. RESULTS: GMI was highest in chronic (mean 9.4) and active (9.7) antibody mediated rejections (ABMR), mixed rejections (7.6), and recurrent or de novo glomerulonephritis (7.5) and differed significantly from normal transplants (1.3) in almost all diagnostic groups. Hazard ratios for graft loss were significantly increased for all biopsies with GMI ≥1.9 compared to GMI < .5 (reference group) in an adjusted Cox regression model and increased with higher GMI levels. Biopsies with GMI ≥ 4.6 had < 60% 10-year graft-survival, compared to > 80% with GMI ≤ 1.8. CONCLUSION: GMI levels were predictive of graft loss independent of histological diagnoses and may guide clinicians to decide follow-up and therapy.

Histological diagnosis from kidney transplant biopsy can contribute to prediction of graft survival.

AIM: The primary aim of this study was to in depth examine if the histological findings in a transplanted kidney biopsy can predict the prognosis for the graft and the patient. The secondary aim was to extend knowledge of the impact of time elapsed on biopsy findings. METHODS: Data from 1462 patients were merged from a kidney transplantation registry and a biopsy registry during 1 January 2007 and 30 September 2017. Kaplan-Meier analysis and multivariate Cox-regression analysis were performed and hazard ratios (HR) with 95% confidence intervals (CI) were presented. RESULTS: Compared to normal biopsy findings, graft survival after biopsy (gsaBiopsy) was shorter for patients with glomerular diseases (HR 8.2, CI:3.2-21.1), rejections (HR 4.2, CI:1.7-10.3), chronic changes including IFTA (HR 3.2, CI:1.3-8.0), acute tubular injuries (HR 3.0, CI:1.2-7.8), and borderline changes (HR 2.9, CI:1.1-7.6). Sub-analysis of rejections showed shorter gsaBiopsy for chronic TCMR (HR 4.7, CI:1.9-11.3), active ABMR (HR 3.6, CI:1.7-7.7) and chronic ABMR (HR 3.5, CI:2.0-6.0). Patients with TCMR Banff grade II (HR 0.35, CI:0.20-0.63) and grade I (HR 0.52, CI:0.29-0.93) had a better gsaBiopsy compared to all other types of rejections. CONCLUSION: Shorter gsaBiopsy was noted in kidneys with glomerular diseases, rejections, acute tubular injuries and borderline changes. TCMR Banff rejections grade I and II were associated with a better prognosis.

Coronary Interventions in Pediatric Congenital Heart Disease.

Coronary artery lesions represent rare conditions in pediatric congenital heart disease and mainly include coronary artery stenoses (CAS) or coronary artery fistulae (CAF). Due to the small vessel size, pediatric percutaneous coronary interventions (PCI) are demanding and studies concerning long-term results are missing. In this retrospective study, we analyzed indications, procedural details, and post-procedural outcomes in pediatric patients who underwent PCI in our institution. For CAS treatment, procedural success was defined as efficient coronary revascularization with a significant improvement of coronary perfusion. CAF treatment was considered successful, when no residual shunt was detectable. From 1995 to 2020, 32 pediatric patients aged ≤ 18 years received interventional treatment for CAS (n = 24/32) or CAF (n = 8/32). Reasons for CAS were post-surgical (n = 15/24) or post-transplant (n = 9/24). Interventional treatment strategies included coronary angioplasty (20/43), stent placement (10/43), and a combination of both (13/43). In-hospital mortality occurred in 6/24 patients and late mortality in 5/24 patients leading to an overall 5-year survival of 62.5%. Early mortality mainly occurred due to post-ischemic myocardial failure. CAF occlusion was performed using coil embolization (n = 3), placement of vascular plugs (n = 3), a combination of both (n = 1), or a combination of coil embolization and a covered stent (n = 1). Treatment of coronary fistulae was successful in all patients with excellent post-procedural results and no follow-up death. PCI in pediatric patients with congenital heart disease can be performed safely and effectively. However, the overall 5-year survival probability of patients with CAS is reduced due to severe ischemic myocardial damage.

CD99 and polymeric immunoglobulin receptor peptides deregulation in critical COVID-19: A potential link to molecular pathophysiology?

Identification of significant changes in urinary peptides may enable improved understanding of molecular disease mechanisms. We aimed towards identifying urinary peptides associated with critical course of COVID-19 to yield hypotheses on molecular pathophysiological mechanisms in disease development. In this multicentre prospective study urine samples of PCR-confirmed COVID-19 patients were collected in different centres across Europe. The urinary peptidome of 53 patients at WHO stages 6-8 and 66 at WHO stages 1-3 COVID-19 disease was analysed using capillary electrophoresis coupled to mass spectrometry. 593 peptides were identified significantly affected by disease severity. These peptides were compared with changes associated with kidney disease or heart failure. Similarities with kidney disease were observed, indicating comparable molecular mechanisms. In contrast, convincing similarity to heart failure could not be detected. The data for the first time showed deregulation of CD99 and polymeric immunoglobulin receptor peptides and of known peptides associated with kidney disease, including collagen and alpha-1-antitrypsin. Peptidomic findings were in line with the pathophysiology of COVID-19. The clinical corollary is that COVID-19 induces specific inflammation of numerous tissues including endothelial lining. Restoring these changes, especially in CD99, PIGR and alpha-1-antitripsin, may represent a valid and effective therapeutic approach in COVID-19, targeting improvement of endothelial integrity.

Urine proteomics for prediction of disease progression in patients with IgA nephropathy.

BACKGROUND: Risk of kidney function decline in immunoglobulin A (IgA) nephropathy (IgAN) is significant and may not be predicted by available clinical and histological tools. To serve this unmet need, we aimed at developing a urinary biomarker-based algorithm that predicts rapid disease progression in IgAN, thus enabling a personalized risk stratification. METHODS: In this multicentre study, urine samples were collected in 209 patients with biopsy-proven IgAN. Progression was defined by tertiles of the annual change of estimated glomerular filtration rate (eGFR) during follow-up. Urine samples were analysed using capillary electrophoresis coupled mass spectrometry. The area under the receiver operating characteristic curve (AUC) was used to evaluate the risk prediction models. RESULTS: Of the 209 patients, 64% were male. Mean age was 42 years, mean eGFR was 63 mL/min/1.73 m2 and median proteinuria was 1.2 g/day. We identified 237 urine peptides showing significant difference in abundance according to the tertile of eGFR change. These included fragments of apolipoprotein C-III, alpha-1 antitrypsin, different collagens, fibrinogen alpha and beta, titin, haemoglobin subunits, sodium/potassium-transporting ATPase subunit gamma, uromodulin, mucin-2, fractalkine, polymeric Ig receptor and insulin. An algorithm based on these protein fragments (IgAN237) showed a significant added value for the prediction of IgAN progression [AUC 0.89; 95% confidence interval (CI) 0.83-0.95], as compared with the clinical parameters (age, gender, proteinuria, eGFR and mean arterial pressure) alone (0.72; 95% CI 0.64-0.81). CONCLUSIONS: A urinary peptide classifier predicts progressive loss of kidney function in patients with IgAN significantly better than clinical parameters alone.

Risk factors for biopsy complications in initial versus subsequent biopsies in native and transplant kidneys.

BACKGROUND: Few studies exist about risk factors for complications in subsequent biopsies. PURPOSE: To explore risk factors for complications in initial versus subsequent biopsies in native and transplant kidneys, which may predict biopsy complications. MATERIAL AND METHODS: In a multicenter study, 2830 native kidney biopsies (4.3% subsequent) were analyzed for major complications (1251 of these were also analyzed for minor) and 667 transplant kidney biopsies (29% subsequent) were analyzed for major and minor complications. No death or nephrectomy were described. Fisher's exact test, Student's t-test, chi-square analyses, and univariate and multiple binary logistic regression analyses were employed; P < 0.05 was considered significant. RESULTS: In initial native kidney biopsies, the frequency of major complications was higher in women compared to men (odds ratio 1.6, 95% confidence interval 1.1-2.2), in younger patients (50 vs. 54 years, P = 0.007), and in patients with lower weight (78 vs. 82 kg, P = 0.005). In subsequent native kidney biopsies, patients with major complications had a higher systolic blood pressure (145 vs. 132 mmHg, P = 0.03). In initial transplant kidney biopsies, biopsies with major complications had less glomeruli in the biopsy (17 vs. 24, P = 0.046). In subsequent transplant kidney biopsies, patients with major complications had a higher mean arterial pressure (112 vs. 98 mmHg, P = 0.002). In subsequent native kidney biopsies, there was a higher number of SLE-nephritis (12% vs. 4.6%, P = 0.001) compared to initial biopsies. CONCLUSION: The different types of risk factors for complications in initial versus subsequent renal biopsies could be important for the clinicians to improve patients' safety.

Allergen-specific IgG+ memory B cells are temporally linked to IgE memory responses.

BACKGROUND: IgE is the least abundant immunoglobulin and tightly regulated, and IgE-producing B cells are rare. The cellular origin and evolution of IgE responses are poorly understood. OBJECTIVE: The cellular and clonal origin of IgE memory responses following mucosal allergen exposure by sublingual immunotherapy (SLIT) were investigated. METHODS: In a randomized double-blind, placebo-controlled, time course SLIT study, PBMCs and nasal biopsy samples were collected from 40 adults with seasonal allergic rhinitis at baseline and at 4, 8, 16, 28, and 52 weeks. RNA was extracted from PBMCs, sorted B cells, and nasal biopsy samples for heavy chain variable gene repertoire sequencing. Moreover, mAbs were derived from single B-cell transcriptomes. RESULTS: Combining heavy chain variable gene repertoire sequencing and single-cell transcriptomics yielded direct evidence of a parallel boost of 2 clonally and functionally related B-cell subsets of short-lived IgE+ plasmablasts and IgG+ memory B cells. Mucosal grass pollen allergen exposure by SLIT resulted in highly diverse IgE and IgGE repertoires. These were extensively mutated and appeared relatively stable as per heavy chain isotype, somatic hypermutations, and clonal composition. Single IgGE+ memory B-cell and IgE+ preplasmablast transcriptomes encoded antibodies that were specific for major grass pollen allergens and able to elicit basophil activation at very low allergen concentrations. CONCLUSION: For the first time, we have shown that on mucosal allergen exposure, human IgE memory resides in allergen-specific IgG+ memory B cells. These cells rapidly switch isotype, expand into short-lived IgE+ plasmablasts, and serve as a potential target for therapeutic intervention.

Renal transplant biopsy complications: assessment of risk factors and potential of desmopressin to decrease risk of hemorrhage.

BACKGROUND: Renal transplant biopsies are essential in nephrology; however, they are invasive and complications can occur. PURPOSE: To explore the risk of transplant kidney biopsy (TxB) complications in relation to possible preventive effects of desmopressin prophylaxis. MATERIAL AND METHODS: A total of 515 consecutive TxB (375 patients, median age 53 years) were analyzed. In 252 TxB, the Resistive Index (RI) was measured right before the biopsy. A total of 282 patients had serum creatinine >150 µmol/L. In one of the six hospitals 39/282 patients consecutively received desmopressin (dose 0.3 µg/kg subcutaneously) as prophylaxis within 1 h before the biopsy. Fisher's exact and χ2 test were used (odds ratio [OR], 95% confidence interval [CI]). Univariate and multiple binary logistic regression analyses were performed. A two-sided P value <0.05 was considered significant. RESULTS: RI ≥ 0.8 was a risk factor for major TxB complications (OR 4.2, 95% CI 1.13-15.76). The risk for minor complications decreased with mean arterial blood pressure (MAP) (97.9 vs. 89.5 mmHg, OR 0.97, 95% CI 0.95-0.997). In a multiple regression analysis for overall biopsy complications, the risk remained increased for patients with RI ≥ 0.8 (OR 4.45, 95% CI 1.32-15.04). No patients (0/39) with desmopressin prophylaxis had a major complication versus 8/243 in the other group. In patients with serum creatinine >150 µmol/L, those with a higher MAP had more overall TxB complications (104.5 vs. 98.2 mmHg, OR 1.05, 95% CI 1.004-1.1). CONCLUSION: RI ≥ 0.8 was a risk factor for major and overall complications and a lower MAP for minor biopsy complications. Desmopressin prophylaxis showed yet no verified benefit as prophylaxis in TxB.

Twiddler's syndrome with occult lead insulation damage in a child with epicardial pacemaker leads.

We present a rare case of incidentally diagnosed Twiddler's syndrome in a child 7 years after implantation of a dual-chamber pacemaker system with epicardial leads. During revision, an insulation defect of the ventricular lead was evident, despite unremarkable prior pacemaker lead testing. The lead was repaired and a new generator was suture-fixated to prevent re-occurrence of generator manipulation.

Treatment strategies for protein-losing enteropathy in Fontan-palliated patients.

OBJECTIVE: Protein-losing enteropathy is an infrequent but severe condition occurring after Fontan procedure. The multifactorial pathogenesis remains unclear and no single proposed treatment strategy has proven universally successful. Therefore, we sought to describe different treatment strategies and their effect on clinical outcome and mortality. MATERIAL AND METHODS: We performed a retrospective observational study. From the total cohort of 439 Fontan patients treated in our institution during the study period 1986-2019, 30 patients (6.8%) with protein-losing enteropathy were identified. Perioperative, clinical, echocardiographic, laboratory, and invasive haemodynamic findings and treatment details were analysed. RESULTS: Median follow-up after disease onset was 13.1 years [interquartile range 10.6]. Twenty-five patients received surgical or interventional treatment for haemodynamic restrictions. Medical treatment, predominantly pulmonary vasodilator and/or systemic anti-inflammatory therapy with budesonide, was initiated in 28 patients. In 15 patients, a stable remission could be achieved by medical or surgical procedures (n = 3 each), by combined multimodal therapy (n = 8), or ultimately by cardiac transplantation (n = 1). Phrenic palsy, bradyarrhythmia, Fontan pathway stenosis, and absence of a fenestration were significantly associated with development of protein-losing enteropathy (p = 0.001-0.48). Ten patients (33.3%) died during follow-up; 5-year survival estimate was 96.1%. In unadjusted analysis, medical therapy with budesonide and pulmonary vasodilator therapy in combination was associated with improved survival. CONCLUSIONS: Protein-losing enteropathy is a serious condition limiting survival after the Fontan procedure. Comprehensive assessment and individual treatment strategies are mandatory to achieve best possible outcome. Nevertheless, relapse is frequent and long-term mortality substantial. Cardiac transplantation should be considered early as treatment option.

Desmopressin (Octostim®) before a native kidney biopsy can reduce the risk for biopsy complications in patients with impaired renal function: A pilot study.

AIM: To evaluate whether the administration of desmopressin alters the risk for renal biopsy complications. METHODS: A multicenter registry containing 576 native kidney biopsies (NKb) with a serum creatinine above 150 µmol/L in 527 patients (372 men and 155 women, median age 61 years) was used. Most of the data were prospective. At one of the hospitals all biopsies with creatinine above 150 µmol/L received desmopressin before biopsies (NKb 204). These were compared to outcome of biopsy complications against other centres where desmopressin was not given (NKb 372). Fisher's exact test, χ2 analyses, univariate and multiple binary logistic regression were used. Data were given as odds ratio (OR) and confidence interval (CI). A two sided P-value of <0.05 was considered significant. RESULTS: In NKb with creatinine >150 µmol/L, those with desmopressin had less overall (3.4% vs 8.4%, OR 0.39, CI 0.17-0.90) whereas major or minor complications were not different. While desmopressin did not exhibit difference in complications in men, women received less major (0% vs 8.6%, P = 0.03) and overall complications (0% vs 12.1%, P = 0.006). A multiple logistic regression revealed that, after adjusting for BMI, age and sex, prophylaxis with desmopressin showed less major (OR 0.38, CI 0.15-0.96) and overall complications (OR 0.36, CI 0.15-0.85). CONCLUSION: Desmopressin given before a native kidney biopsy in patients with impaired renal function can reduce the risk for complications.

Interventional re-opening of a PDA for reverse potts shunt circulation after ADO i implantation in a child.

We report interventional re-opening of a PDA for reverse Potts shunt circulation 12 months after closure in a 3.8 year old child, suffering from right ventricular (RV) failure due to suprasystemic pulmonary artery hypertension (PAH) after ADO I implantation. After ex vivo simulation, perforation through the mesh of the ADO I with the use of transseptal needle, wire looping (AO-PA), balloon dilatation, stent implantation (Palmaz 6 mm) and post dilatation, a reverse Pott-shunt circulation was established. A follow-up period of 11 months was achieved with preserved RV function and reverse Pott shunt circulation maintained a post ductal saturation of 94-88%. © 2016 Wiley Periodicals, Inc.

Characterization of membrane-bound dehydrogenases of Gluconobacter oxydans 621H using a new system for their functional expression.

Acetic acid bacteria are used in biotechnology due to their ability to incompletely oxidize a great variety of carbohydrates, alcohols, and related compounds in a regio- and stereo-selective manner. These reactions are catalyzed by membrane-bound dehydrogenases (mDHs), often with a broad substrate spectrum. In this study, the promoters of six mDHs of Gluconobacter oxydans 621H were characterized. The constitutive promoter of the alcohol dehydrogenase and the glucose-repressed promoter of the inositol dehydrogenase were used to construct a shuttle vector system for the fully functional expression of mDHs in the multi-deletion strain G. oxydans BP.9 that lacks its mDHs. This system was used to express each mDH of G. oxydans 621H, in order to individually characterize the substrates, they oxidize. From 55 tested compounds, the alcohol dehydrogenase oxidized 30 substrates and the polyol dehydrogenase 25. The substrate spectrum of alcohol dehydrogenase overlapped largely with the aldehyde dehydrogenase and partially with polyol dehydrogenase. Thus, we were able to resolve the overlapping substrate spectra of the main mDHs of G. oxydans 621H. The described approach could also be used for the expression and detailed characterization of substrates used by mDHs from other acetic acid bacteria or a metagenome.

Expression of membrane-bound dehydrogenases from a mother of vinegar metagenome in Gluconobacter oxydans.

Acetic acid bacteria are well-known for their membrane-bound dehydrogenases rapidly oxidizing a variety of substrates in the periplasm. Since many acetic acid bacteria have not been successfully cultured in the laboratory yet, studying membrane-bound dehydrogenases directly from a metagenome of vinegar microbiota seems to be a promising way to identify novel variants of these enzymes. To this end, DNA from a mother of vinegar was isolated, sequenced, and screened for membrane-bound dehydrogenases using an in silico approach. Six metagenomic dehydrogenases were successfully expressed using an expression vector with native promoters in the acetic acid bacterium strain Gluconobacter oxydans BP.9, which is devoid of its major native membrane-bound dehydrogenases. Determining the substrates converted by these enzymes, using a whole-cell DCPIP assay, revealed one glucose dehydrogenase with an enlarged substrate spectrum additionally oxidizing aldoheptoses, D-ribose and aldotetroses, one polyol dehydrogenase with an extreme diminished spectrum but distinguishing cis and trans-1,2-cyclohexandiol and a completely new secondary alcohol dehydrogenase, which oxidizes secondary alcohols with a hydroxyl group at position 2, as long as no primary hydroxyl group is present. Three further dehydrogenases were found with substrate spectra similar to known dehydrogenases of G. oxydans 621H.

Sixteen Gauge biopsy needles are better and safer than 18 Gauge in native and transplant kidney biopsies.

Background Kidney biopsies are essential for optimal diagnosis and treatment. Purpose To examine if quality and safety aspects differ between types and sizes of biopsy needles in native and transplant kidneys. Material and Methods A total of 1299 consecutive biopsies (1039 native and 260 transplant kidneys) were included. Diagnostic quality, needle size and type, clinical data and complications were registered. Eight-three percent of the data were prospective. Results In native kidney biopsies, 16 Gauge (G) needles compared to 18 G showed more glomeruli per pass (11 vs. 8, P < 0.001) with less complications. Sub-analysis in native kidney biopsies revealed that 18 G 19-mm side-notch needles resulted in more major (11.3% vs. 3%; odds ratio [OR], 4.1; 95% confidence interval [CI], 1.4-12.3) and overall complications (12.4% vs. 4.8%; OR, 2.8; 95% CI, 1.1-7.1) in women than in men. If the physician had performed less compared to more than four native kidney biopsies per year, minor (3.5% vs. 1.4%; OR, 2.6; 95% CI, 1.1-6.2) and overall complications (11.5% vs. 7.4%; OR, 1.6; 95% CI, 1.1-2.5) were more common. In transplant kidney biopsies, 16 G needles compared to 18 G resulted in more glomeruli per pass (12 vs. 8, P < 0.001). No differences existed in frequency of biopsy complications. The localization of performing biopsies was not a risk factor to develop complications. Conclusion Kidney biopsies taken by 16 G needles result in better histological quality and lower frequency of complications compared to 18 G. For native kidney biopsies the performer of the biopsy should do at least four biopsies per year.

Relapsing-remitting central nervous system autoimmunity mediated by GFAP-specific CD8 T cells.

Multiple sclerosis (MS) is an inflammatory disease of the CNS that causes the demyelination of nerve cells and destroys oligodendrocytes, neurons, and axons. Historically, MS has been thought to be a CD4 T cell-mediated autoimmune disease of CNS white matter. However, recent studies identified CD8 T cell infiltrates and gray matter lesions in MS patients. These findings suggest that CD8 T cells and CNS Ags other than myelin proteins may be involved during the MS disease process. In this article, we show that CD8 T cells reactive to glial fibrillary acidic protein (GFAP), a protein expressed in astrocytes, can avoid tolerance mechanisms and, depending upon the T cell-triggering event, drive unique aspects of inflammatory CNS autoimmunity. In GFAP-specific CD8 TCR-transgenic (BG1) mice, tissue resident memory-like CD8 T cells spontaneously infiltrate the gray matter and white matter of the CNS, resulting in a relapsing-remitting CNS autoimmunity. The frequency, severity, and remissions from spontaneous disease are controlled by the presence of polyclonal B cells. In contrast, a viral trigger induces GFAP-specific CD8 T effector cells to exclusively target the meninges and vascular/perivascular space of the gray and white matter of the brain, causing a rapid, acute CNS disease. These findings demonstrate that the type of CD8 T cell-triggering event can determine the presentation of distinct CNS autoimmune disease pathologies.