First-line daratumumab shows high efficacy and tolerability even in advanced AL amyloidosis: the real-world experience

Background

Daratumumab was the first monoclonal CD38 antibody with single-agent activity approved for the treatment of multiple myeloma. Moreover, daratumumab demonstrated high response rates in relapsed immunoglobulin light-chain (AL) amyloidosis.

Patients and methods

In our single-center retrospective real-life case series, we analyzed the efficacy and safety of daratumumab as first-line treatment. Daratumumab was administered with low-dose dexamethasone alone or in combination with other multiple myeloma therapeutics

Results

Fourteen patients were eligible, including nine patients with cardiac stage IIIa or IIIb. Overall hematologic response rate was 100%, with 64.3% achieving complete response after a median of 16 cycles of treatment. Median time to hematologic response was 1.4 months. Organ response rates were 45.5% after a median of 4.0 months and 66.7% after a median of 10.0 months, for heart and kidney involvement, respectively. After a median follow-up of 20.5 months, two patients underwent successful autologous stem cell transplantation (ASCT), while another three patients were in preparation for ASCT. Three patients remained on daratumumab at the last follow-up. There were no unexpected toxicities and no grade III or IV adverse events, although more than half of our patients were in stage IIIa or IIIb.

Conclusion

Daratumumab proved to be highly effective in newly diagnosed AL amyloidosis with excellent hematologic and organ response rates, a remarkable safety profile, and good tolerability even in patients with advanced stage of disease.

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Daratumumab yields high hematologic response rates in untreated AL amyloidosis.

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Treatment is well tolerated even in advanced disease stages.

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No unexpected toxicity was observed.

Blood Lactate And Lactate Clearance: Refined Biomarker And Prognostic Marker In Burn Resuscitation

Adequate resuscitation of acute burn patients is important to ensure end organ perfusion and oxygenation. The ideal marker to the endpoint of burn resuscitation is still not established. We aimed to evaluate the role of blood lactate and lactate clearance in burn resuscitation and their association with mortality and sepsis in burn patients. The retrospective study included patients (18-50 years) with thermal and scald burns with total body surface area of 30% to 60% over a period of 9 months who had achieved target urine output of at least 0.5ml/kg/hr within 24 hours of resuscitation. Patients were divided based on their admission blood lactate levels (Group A < 2 mmol/L and Group B > 2 mmol/L). Group B was further subdivided into Group B1 in whom blood lactate levels reached less than 2 mmol/L within 24 hours of burn resuscitation and Group B2 in whom it did not. Total patients included were 203. Mortality (M) and sepsis (S) rates in subgroup B2 were higher (M=57.9%; S=43.5%) and rates in subgroup B1 (M=25.8%; S=27.4%) were comparable to Group A (M=27.8%; S=26.4%). Persistent lactic acidosis at 24 hours was independently associated with significantly increased mortality and sepsis. Our data suggests a correlation of blood lactate levels and lactate clearance within 24 hours of admission with mortality and sepsis related to burn injury.

P2727Hemodynamic profiles in patients with cardiac amyloidosis

Background

Intracardiac filling and pulmonary arterial pressures play a central role in various heart failure entities, as they are strong predictors of outcome. However, their role in patients with cardiac amyloidosis (CA) is less clear.

Purpose

We aimed to characterize hemodynamic profiles of CA patients and assess their association with outcomes.

Methods

The present study was conducted within a prospective, national CA registry.

Patients underwent invasive hemodynamic, clinical, laboratory, and echocardiography assessment, as well cardiac magnetic resonance imaging with T1-mapping. The main outcome measure was a combined endpoint consisting of hospitalization for heart failure or cardiovascular death.

Results

Between March 2012 and October 2018, 63 consecutively recruited CA patients underwent invasive hemodynamic profiling. Of those, 36 had cardiac transthyretin amyloidosis (ATTR) and 25 cardiac light-chain amyloidosis (AL). In two patients amyloid subtyping was not possible.

Median age of the study population was 74.0 years and the majority were male (61.9%). Almost half of the patients were in New York Heart Association (NYHA) class ≥III (47.6%) and showed elevated N-terminal prohormone of brain natriuretic peptides (NT-proBNP) with a median of 3222 pg/mL. In comparison to AL, cardiac TTR patients were older (75.0 years versus 69.0 years, p=0.004), more often male (80.6% versus 40.0%, p=0.001), less symptomatic (NYHA class ≥III: 38.9% versus 64.0%, p=0.021), and had lower NT-proBNP values (2324pg/mL versus 5151pg/mL, p=0.004).

Hemodynamic profiling revealed significantly increased intracardiac as well as pulmonary arterial pressures (PAP). On an average, pulmonary artery wedge pressure was 20.0mmHg [interquartile range (IQR): 17.0–25.0], mean PAP (mPAP) was 30.0mmHg (IQR: 25.0–37.0), and mean right atrial pressure (mRAP) was 11.0mmHg (IQR: 7.0–16.0). No differences between ATTR and AL patients could be detected (p=0.148, p=0.398, p=0.620). During a median follow-up of 63.0 weeks, 28 study participants (44.4%) reached the combined endpoint. Moreover, cardiac AL patients had significantly more events as their ATTR counterparts (72.0% versus 27.8%, p=0.001). In cardiac ATTR patients, mPAP was significantly associated with outcome [hazard ratio (HR): 1.083, p=0.034, Figure 1A], which was not the case in the AL group (HR: 1.024, p=0.186, Figure 1B). Cardiac output and pulmonary vascular resistance were not associated with outcome. Neither in the ATTR (p=0.144; p=0.063) nor in AL cohort (p=0.420; p=0.115).

Figure 1

Conclusion

Despite differences in the severity of symptoms between cardiac AL and cardiac ATTR patients, no differences with regards to hemodynamic profiles could be detected.

Furthermore, intracardiac filling and pulmonary arterial pressures seem to be of greater clinical importance in cardiac ATTR as compared to cardiac AL, as these parameters were associated with outcome in the first, but not the latter group.

P2726Extremely boosted prediction of cardiac amyloidosis by routine laboratory paramaters

Background/Introduction

Cardiac amyloidosis (CA) is a rare and complex condition with poor prognosis. Novel therapies have been shown to improve outcome, however, most of the affected individuals remain undiagnosed, mainly due to a lack in awareness among clinicians. One approach to overcome this issue is to use automated diagnostic algorithms that act based on routinely available laboratory results.

Purpose

We tested the performance of flexible machine learning and traditional statistical prediction models for non-invasive CA diagnosis based on routinely collected laboratory parameters. Since laboratory routines vary between hospitals or other health care providers, special attention has been taken to adaptive and dynamic parameter selection, and to dealing with the frequent occurrence of missing values.

Methods

Our cohort consisted of 376 clinically accepted patients with various types of heart failure. Of these, 69 were diagnosed with CA via endomyocardial biopsy (positives), and 307 had unrelated cardiac disorders (negatives). A total of 63 routine laboratory parameters were collected from these patients, with a high incidence of missing values (on average 60% of patients for each parameter). We tested the performance of two prediction models: logistic regression, and extreme gradient boosting with regression trees. To deal with missing values we adopted two strategies: a) finding an optimal overlap of parameters and deleting all patients with missing values (reduction of parameters and samples), and b) retaining all features and imputing missing values with parameter-wise means. To fairly assess the performance of prediction models we employed a 10-fold cross validation (stratified to preserve sample class ratio). Finally, area under curve for receiver-operator characteristic (ROC AUC) was used as our final performance measure.

Results

A complex machine learning model based on forests of regression trees proved to be the most performant (ROC AUC 0.94±4%) and robust to missing values. The best regression model was obtained with the 25 most frequent variables and patient deletion in case of missing values (ROC AUC 0.82±0.8%). While progressive inclusion of predictor variables worsened the performance of the logistic regression, it increased that of the machine learning approach.

Conclusions

Extreme gradient boosting of regression trees by routine laboratory parameters achieved staggering accuracy results for the automated diagnosis of CA. Our data suggest that implementations of such algorithms as independent interpreters of routine laboratory results may help to establish or suggest the diagnosis of CA in patients with heart failure symptoms, even in the absence of specialized experts.

Adhesion of Escherichia coli under flow conditions reveals potential novel effects of FimH mutations

FimH-mediated adhesion of Escherichia coli to bladder epithelium is a prerequisite for urinary tract infections. FimH is also essential for blood-borne bacterial dissemination, but the mechanisms are poorly understood. The purpose of this study was to assess the influence of different FimH mutations on bacterial adhesion using a novel adhesion assay, which models the physiological flow conditions bacteria are exposed to. We introduced 12 different point mutations in the mannose binding pocket of FimH in an E. coli strain expressing type 1 fimbriae only (MSC95-FimH). We compared the bacterial adhesion of each mutant across several commonly used adhesion assays, including agglutination of yeast, adhesion to mono- and tri-mannosylated substrates, and static adhesion to bladder epithelial and endothelial cells. We performed a comparison of these assays to a novel method that we developed to study bacterial adhesion to mammalian cells under flow conditions. We showed that E. coli MSC95-FimH adheres more efficiently to microvascular endothelium than to bladder epithelium, and that only endothelium supports adhesion at physiological shear stress. The results confirmed that mannose binding pocket mutations abrogated adhesion. We demonstrated that FimH residues E50 and T53 are crucial for adhesion under flow conditions. The coating of endothelial cells on biochips and modelling of physiological flow conditions enabled us to identify FimH residues crucial for adhesion. These results provide novel insights into screening methods to determine the effect of FimH mutants and potentially FimH antagonists.

Polyetiology of Renal Allograft Dysfunction

In 101 consecutive patients with renal allograft dysfunction a correlation of Duplex Doppler sonography (DDS) with histopathologic reports of simultaneously performed biopsies was made. Renal vascular impedance was estimated by calculating the resistive index (RI). A total of 290 different specific histologic diagnoses (mean 2.1 ± 0.84 diagnoses/biopsy) was noted. With increasing time interval to transplantation, single diagnoses as cause of allograft dysfunction decreased. DDS could not reliably differentiate, exclude, or grade any of the common causes of renal allograft dysfunction like vascular and/or cellular rejection, chronic rejection, acute tubular necrosis, cyclosporin nephrotoxicity, relapse of glomerulonephritis and infection. Follow-up studies after established histologic diagnosis in 19 patients with persisting allograft dysfunction demonstrated a lack of sensitivity of DDS to significant superimposed causes of transplant malfunction. We conclude that biopsy is still necessary to direct proper therapy of renal allograft dysfunction.

Interdigitating dendritic cell sarcoma of the parotid gland

Interdigitating dendritic cell sarcomas (IDCSs) are extremely uncommon tumours that arise predominantly in lymphoid tissue. We report a case of an IDCS arising in the parotid gland of a 73-year-old man. Clinically, a primary salivary gland tumour was suspected but fine needle aspiration cytology suggested a soft tissue tumour. A diagnosis of IDCS was made on histopathological examination of the resection specimen, with subsequent confirmation by electron microscopy. Given the extreme rarity of this tumour at this site, it is unlikely to be a common diagnostic problem, but the importance of multiple diagnostic modalities is emphasized. The findings of cytology, histology, immunohistochemistry and electron microscopy have not previously been described together in a single case report of this tumour.

Cryopreservation of a whole ovary as a strategy for restoring ovarian function

PURPOSE

To evaluate whether a total ovary can successfully be cryopreserved and thawed under maintenance of high proportions of structurally normal primordial follicles.

METHODS

Porcine ovaries were explanted immediately after slaughtery. Ten ovaries were cooled to -196 degrees C using cryoprotective solution and a computer-controlled freezing technique. Five contralateral ovaries were fixed with formalin for histological examination, the five remaining ovaries were directly plunged in liquid nitrogen. After three weeks of storage, frozen ovaries were thawed and examined by light and electron microscopy. Viability was assessed by evaluation of intact primordial follicles with respect to cellular and intracellular structures.

RESULTS

Histological viability of primordial follicles in computer-frozen ovaries was 84.4% (76.1-90.6%), as compared to non-frozen control samples (92-100%; mean 97.6%) and to ovaries plunged in liquid nitrogen without cryoprotection 21.1% (4.5-35.0%).

CONCLUSIONS

Cryopreservation of whole ovaries may present a feasible way to maintain high numbers of viable primordial follicles in ovarian tissue retransplantation.

Plastic surgery in rural area: A report

Most of our rural population does not seek the expensive specialist service of distant city hospitals due to social or financial reasons. Existing health system in rural area is not efficient enough to meet the health demands of such vast population. There is only one Government Plastic surgery unit covering the population of 40 lacs leading to huge backlog of patients waiting for reconstructive surgery. To evade this situation a team of Plastic surgeons from Government Medical College Jabalpur goes to rural areas twice a year and has operated in on nine occasions since last 4 years.

The activities and experiences of the last nine visits are reported here.

Immunological risk factors are solely responsible for primary non-function of renal allografts

Primary non-function (PNF) of renal allografts has been attributed to various risk factors, among them immunological ones, as well as unfavourable preservation conditions. To investigate the impact of these risk factory on the occurrence of PNF, 1335 consecutive kidney transplants performed at a single centre over a 10-year period were analysed. All patients received immunosuppression based on cyclosporine. As the method of analysis a conditional stepwise logistic regression model was chosen, comparing each graft suffering PNF with its partner kidney retrieved from the same donor. Thus, all donor-related variables could be omitted from the analysis, as they are the same in every pair of grafts. Risk factors analysed included panel-reactive antibodies, number of pretransplant transfusions, pregnancies, number of prior transplants, cold and second warm ischaemia time, mismatches on HLA loci A, B and DR and recipient age. The overall incidence of PNF was 87 grafts (6.5%). One patient suffered immediate rejection due to transplantation of an ABO incompatible graft. This case was excluded from further analysis. PNF occurred three times in recipients of living related grafts, twice in recipients of en-bloc grafts and four times in grafts, in which the paired kidney was either not transplanted or shipped outside the Eurotransplant region, so that no paired graft was available for matched case-control analysis. Of the remaining 77 pairs, twice both organs of one donor failed immediately. The remaining 73 complete pairs were analysed. Two of the investigated risk factors have independently a significant impact on the occurrence of PNF. Increasing the number of pretransplant transfusions raises the relative risk of graft failure up to six fold (P=0.02), while a history of prior transplants bears a relative risk of 0.21E05 (P=0.005). Ischaemia has no significant impact on the occurrence of PNF. Our data strongly suggest that immunological rather than donor risk factors are responsible for the non-function of kidney grafts.

The ephrin-A1 ligand and its receptor, EphA2, are expressed during tumor neovascularization

Eph receptor tyrosine kinases and their ephrin ligands have been implicated in embryonic vascular development and in in vivo models of angiogenesis. Eph proteins may also regulate tumor neovascularization, but this role has not been previously investigated. To screen for Eph proteins expressed in tumor blood vessels, we used tumor xenografts grown in nude mice from MDA-MB-435 human breast cancer cells or KS1767 human Kaposi's sarcoma cells. By immunohistochemistry, the ephrin-A1 ligand and one of its receptors, EphA2, were detected throughout tumor vasculature. Double-labeling with anti-CD34 antibodies demonstrated that both ephrin-A1 and EphA2 were expressed in xenograft endothelial cells and also tumor cells. Furthermore, EphA2 was tyrosine-phosphorylated in the xenograft tumors, indicating that it was activated, presumably by interacting with ephrin-A1. Ephrin-A1 and EphA2 were also detected in both the vasculature and tumor cells of surgically removed human cancers. In an in vitro angiogenesis model, a dominant negative form of EphA2 inhibited capillary tube-like formation by human umbilical vein endothelial cells (HUVECs), demonstrating a requirement for EphA receptor signaling. These data suggest that ephrin-A1 and EphA2 play a role in human cancers, at least in part by influencing tumor neovascularization. Eph proteins may represent promising new targets for antiangiogenic cancer treatments.

The Duffy antigen receptor for chemokines is up-regulated during acute renal transplant rejection and crescentic glomerulonephritis

BACKGROUND

Recruitment of leukocytes during immune responses requires the coordinate expression of adhesion molecules in concert with chemokines and their receptors. The Duffy antigen receptor for chemokines (DARC) binds multiple chemokines and is expressed on postcapillary venules in the normal kidney. The chemokine receptor CCR5, which shares the ligand regulated upon activation, normal T-cell expressed and secreted (RANTES) with DARC, is expressed by infiltrating T cells in the renal interstitium. As DARC might be involved in the attraction of CCR5-positive cells, we studied the distribution of DARC and CCR5 in two forms of cell-mediated renal injury: renal allograft rejection and crescentic glomerulonephritis (cGN).

METHODS

A total of 87 renal specimens, including 12 pretransplant biopsies, 47 transplant biopsies (Banff 1, N = 10; Banff 2, N = 19; and various other lesions N = 18), and 28 biopsies from patients with cGN, was analyzed. Immunohistochemistry for CCR5 and DARC was performed on serial sections of formalin-fixed and paraffin-embedded tissue.

RESULTS

Compared with pretransplant biopsies, the mean number of DARC-positive interstitial venules was significantly increased during both transplant rejection and cGN. This was accompanied by an infiltration of CCR5-positive leukocytes. During transplant rejection, the number and distribution of CCR5-positive cells correlated with DARC-positive venules. Infiltrating CCR5-positive leukocytes were found mainly in the interstitium, often clustering around Bowman's capsules in biopsies from cGN. The number of glomerular CCR5 positive cells is low, but they are common in a subset of crescents.

CONCLUSIONS

We hypothesize that the increased number of DARC-positive venules in areas of interstitial injury and the colocalization with CCR5-positive infiltrating leukocytes may indicate a role for endothelial DARC expression during leukocyte adhesion and interstitial infiltration.

Renal oncocytoma with prominent intracytoplasmic vacuoles of mitochondrial origin

AIMS

We observed two oncocytomas with prominent intracytoplasmatic vacuoles. To investigate if this previously undescribed finding is a diagnostic feature and compatible with the diagnosis of oncocytoma, we characterized these vacuoles by electron microscopy and immunohistochemistry.

METHODS AND RESULTS

The tumours were analysed by transmission electron microscopy. Immunohistochemistry was performed with antimitochondrial antibody, anti-Golgi-zone antibody, anti-lysozyme antibody and anti-human-trans-Golgi-network antibody. By electron microscopy, the vacuoles were found to be double-membrane-bounded, and some contained fragmented christae. Immunohistochemistry showed a positive reaction of the vacuoles with anti-mitochondrial antibody. Staining with anti-Golgi-zone antibody, anti-lysozyme antibody and anti-human-trans-Golgi-network antibody was negative.

CONCLUSION

Both tumours are benign oncocytomas. The phenomena of cells with prominent intracytoplasmatic vacuoles is not inconsistent with the diagnosis of oncocytoma. The vacuoles are of mitochondrial origin and may develop, by balloon degeneration, as a mechanism of mitochondrial involution and elimination.

Capillary haemangioma of the testis

A case of testicular capillary haemangioma is reported and the importance of intraoperative examination of this very rare lesion emphasised. Capillary haemangioma of the testis can be similar to malignant testicular tumours on clinical presentation, as well as on ultrasonography and magnetic resonance imaging, and therefore should be included in the intraoperative differential diagnosis. Because of the benign nature of this lesion, conservative surgical treatment by means of tumour enucleation with preservation of the testis is possible, if intraoperative examination of frozen sections of representative tissue can be performed.

[Ovarian tissue banking--primary results]

Lifelong hormone replacement therapy and infertility often follow oncological therapy in young women due to a dramatic reduction of the primordial follicle reserve. Reimplantation and function of frozen ovarian tissue slices were successfully demonstrated in animal models, but the durability is limited. Cryopreservation of a whole ovary could reestablish an almost normal ovarian function. Experiments with porcine ovaries showed histological viability. Cryopreservation and retransplantation of sheep ovaries should demonstrate success by hormonal response and pregnancy.

Anti-cancer activity of targeted pro-apoptotic peptides

We have designed short peptides composed of two functional domains, one a tumor blood vessel 'homing' motif and the other a programmed cell death-inducing sequence, and synthesized them by simple peptide chemistry. The 'homing' domain was designed to guide the peptide to targeted cells and allow its internalization. The pro-apoptotic domain was designed to be nontoxic outside cells, but toxic when internalized into targeted cells by the disruption of mitochondrial membranes. Although our prototypes contain only 21 and 26 residues, they were selectively toxic to angiogenic endothelial cells and showed anti-cancer activity in mice. This approach may yield new therapeutic agents.

Molecular cloning and expression of a novel human trans-Golgi network glycoprotein, TGN51, that contains multiple tyrosine-containing motifs

Previously, it has been shown that glycoproteins with approximately 130-kDa molecular mass react with antisera from patients with renal vasculitis (Kain, R., Matsui, K., Exner, M., Binder, S., Schaffner, G., Sommer, E. M., and Kerjaschki, D. (1995) J. Exp. Med. 181, 585-597). To search for a molecule that reacts with the antibodies, we screened a lambdagt11 human placental cDNA library. Two of the isolated clones were found to encode a putative counterpart of the rodent trans-Golgi network (TGN) glycoprotein 38, hTGN46, which has the tyrosine containing motif YQRL shared by mouse and rat TGN38. Moreover, reverse transcription-polymerase chain reaction analysis of hTGN46 transcripts and genomic analysis of a cDNA deposited as an expressed sequence tag in dbEST Data Base revealed that additional cDNAs exist that are produced by alternate usage of 3'-splice sites of intron III. Alternative splicing results in frame shifts and leads to novel larger translation products with one (for hTGN48) or two (for hTGN51) additional tyrosine-containing motifs. hTGN51 expressed in Chinese hamster ovary cells were localized to the trans-Golgi network, overlapping with beta-1,4-galactosyltransferase even after mutating the tyrosine-containing motif common to hTGN46. In contrast, mutated hTGN48 and hTGN46 are no longer retrieved to the TGN. These results strongly suggest that hTGN51 may have a unique function compared with hTGN46 or hTGN48 in shuttling between the cell surface and the TGN.

A novel variant of lysosomal acid lipase in cholesteryl ester storage disease associated with mild phenotype and improvement on lovastatin

Cholesterol ester storage disease (CESD) is a rare congenital disorder of lipid metabolism, with mutation of the lysosomal acid lipase gene, causing chronic liver disease, usually before adolescence. We here describe three adult siblings with CESD diagnosed by light microscopic demonstration of excessive lysosomal storage of lipids with accumulation of foamy cells in liver biopsies and by a decrease in acid lipase activity (2-3% of controls). One patient (male, 46a) had extensive liver fibrosis, another (female, 58a) had cirrhosis of the liver. The third patient had died from variceal haemorrhage (female, 56a). Using sequence analysis of RT-PCR products of LAL mRNA, the patients were identified as compound heterozygotes for a G-->A substitution at position -1 of the exon 8 splice donor site and a point mutation at the second allele, resulting in a His108-->Pro shift. In two patients, therapy with lovastatin was initiated, which led to normalisation of serum cholesterol and triglyceride levels. After 12 months, liver biopsy demonstrated a significant decrease in vacuolisation of hepatocytes, with fewer and smaller droplets. Semi-automated computer-assisted image analysis of electron microscopic sections demonstrated a decrease in the hepatocellular lysosomal area from 20.5+/-7.1% to 11.7+/-6.5% (p<0.05) and 41.7+/-5.1% to 33.4+/-4.4% (p<0.01). We conclude that in two siblings with a novel LAL variant and mild phenotype of CESD, lovastatin decreased both serum lipid concentrations and hepatocellular lysosomal content.

Altered Golgi localization of core 2 beta-1,6-N-acetylglucosaminyltransferase leads to decreased synthesis of branched O-glycans

Mucin type O-glycans with core 2 branches are distinct from nonbranched O-glycans, and the amount of core 2 branched O-glycans changes dramatically during T cell differentiation. This oligosaccharide is synthesized only when core 2 beta-1, 6-N-acetylglucosaminyltransferase (C2GnT) is present, and the expression of this glycosyltransferase is highly regulated. To understand how O-glycan synthesis is regulated by the orderly appearance of glycosyltransferases that form core 2 branched O-glycans, the subcellular localization of C2GnT was determined by using antibodies generated that are specific to C2GnT. The studies using confocal light microscopy demonstrated that C2GnT was localized mainly in cis to medial-cisternae of the Golgi. We then converted C2GnT to a trans-Golgi enzyme by replacing its Golgi retention signal with that of alpha-2,6-sialyltransferase, which resides in trans-Golgi. Chinese hamster ovary cells expressing wild type C2GnT and the chimeric C2GnT were then subjected to oligosaccharide analysis. The results obtained clearly indicate that the conversion of C2GnT into a trans-Golgi enzyme resulted in a substantial decrease of core 2 branched oligosaccharides. These results, taken together, strongly suggest that the predominance of core 2 branched oligosaccharides in those cells expressing C2GnT is due to the fact that C2GnT is located earlier in the Golgi than alpha-2,3-sialyltransferase that competes with C2GnT for the common substrate. Furthermore, alteration of Golgi localization renders the chimeric C2GnT much less efficient in synthesizing core 2 branched oligosaccharides, indicating the critical role of orderly subcellular localization of glycosyltransferases.

[Microscopic polyangiitis with eosinophilia--an overlap syndrome or separate disease entity? A case report and review of the literature]

Systemic vasculitides are potentially life-threatening diseases. Early and appropriate diagnosis based on case history, clinico-pathological features, and laboratory parameters, such as the presence of anti-neutrophil cytoplasmic antibodies (ANCA), is crucial for starting appropriate and, often, life-saving therapeutic measures. We report a 50-year-old female patient who presented with fever, arthralgias and hemoptysis. Skin signs included disseminated hemorrhagic pustules, ulcerations of oral and genital mucosa, subcutaneous nodules on arms and legs, and a pyoderma gangrenosum-like lesion on the right leg. Laboratory investigations revealed a peripheral eosinophilia and a positive cANCA titer. Histopathologic analysis of various biopsy specimens showed a granulomatous vasculitis in the subcutis, a nongranulomatous vasculitis with massive eosinophil infiltration in the lungs, and a segmental, necrotizing glomerulonephritis in the kidneys. Differential diagnosis included Wegener's granulomatosis, microscopic polyangiitis (MPA) and Churg-Strauss syndrome. MPA was diagnosed based on clinical and histopathological criteria. An interesting feature of this case was marked peripheral and tissue eosinophilia. Therapy consisted of cyclophosphamide and methylprednisolone. The patient went into a long-lasting clinical remission one month after starting therapy.

A novel class of autoantigens of anti-neutrophil cytoplasmic antibodies in necrotizing and crescentic glomerulonephritis: the lysosomal membrane glycoprotein h-lamp-2 in neutrophil granulocytes and a related membrane protein in glomerular endothelial cells

Necrotizing and crescentic glomerulonephritis (NCGN) is frequently associated with circulating antineutrophil cytoplasmic autoantibodies (ANCA). It is established that ANCA are specific for soluble enzymes of granules of polymorphonuclear neutrophil granulocytes (PMN), such as myeloperoxidase (MPO) or protease 3 (PR3). The purpose of this study was to identify membrane proteins of PMNs, and/or glomerular cells, as additional autoantigenic ANCA targets. When membrane protein fractions were prepared from PMNs and isolated human glomeruli, and immunoblotted with ANCA sera of NCGN patients, two bands with apparent molecular masses of 170 and 80-110 kD (gp170/80-110) were labeled in PMNs, and a 130-kD glycoprotein (gp130) in glomeruli. Gp130 was purified, and monoclonal and rabbit antibodies (Abs) were produced which showed the same double specificity as the patient's ANCA. Using these probes, evidence was provided that gp170/80-110 is identical with human lysosomal-associated membrane protein 2 (h-lamp-2), because both proteins were immunologically cross-reactive and screening of a cDNA expression library from human promyelocytic leukemia cells with anti-gp130 Ab yielded a clone derived from h-lamp-2. Gp170/80-110 was localized primarily in granule membranes of resting PMNs, and was translocated to the cell surfaces by activation with FMLP. By contrast, gp130 was localized in the surface membranes of endothelial cells of human glomerular and renal interstitial capillaries, rather than in lysosomes, as found for h-lamp-2. Potential clinical relevance of autoantibodies to gp170/80-110 and gp130 was assessed in a preliminary trial, in which ANCA sera of patients (n = 16) with NCGN were probed with purified or recombinant antigens. Specific reactivity was detected in approximately 90% of cases with active phases of NCGN, and frequently also in combination with autoantibodies specific for PR3 or MPO. Collectively, these data provide evidence that h-lamp-2 in PMNs and a different, structurally related 130-kD membrane protein on the cell surface of renal microvascular endothelial cells are autoantigenic targets for ANCA in patients with active NCGN.

[Ultrasound-guided fine-needle biopsy with an automatic full-incision system: the initial experiences and comparison with a conventional biopsy gun]

The purpose of this study was to evaluate the efficacy of a new automatic biopsy device (Autovac, Angiomed, Karlsruhe, Germany) in ultrasound (US) guided biopsies of focal abdominal lesions. 50 consecutive patients with focal abdominal lesions underwent US guided biopsies. In the first 24 patients, needle passes were performed with the Autovac system (outer diameter 0.95 mm) as well as with the Biopty gun (outer diameter 0.9 mm) (Bard Covington, USA). The size and the quality of the histologic and the cytologic material obtained by both systems were evaluated by histopathologists blinded to the system used. Autovac yielded significantly more material (defined as the area of the obtained tissue cores) and a significantly higher quality score than did the Biopty system. 96% of the histologic specimen and 100% of the cytologic smears obtained with Autovac were diagnostic, compared to 70 and 81% with Biopty, respectively. With the exception of a short-time elevation of the blood pressure in one patient, no complications occurred. The results indicate an advantage of the automatic full-cut type system Autovac over the tru-cut type Biopty gun in US-guided biopsies of focal abdominal lesions.

Renal biopsy: in vitro and in vivo comparison of a new automatic biopsy device and conventional biopsy systems. Work in progress

A nondisposable full-cut biopsy gun with a disposable needle (system 1, prototype of system 2) and a disposable gun-needle combination (system 2) were compared with conventional needles and Tru-Cut-type biopsy systems in renal parenchymal biopsy procedures. In cadaveric kidneys, more glomeruli were harvested with system 1 than with four other biopsy systems. In native kidneys, more glomeruli were harvested and core quality was better with system 2 than with a Tru-Cut-type biopsy gun.

Polyetiology of renal allograft dysfunction. Does calculation of the resistive index still make sense?

In 101 consecutive patients with renal allograft dysfunction a correlation of Duplex Doppler sonography (DDS) with histopathologic reports of simultaneously performed biopsies was made. Renal vascular impedance was estimated by calculating the resistive index (RI). A total of 290 different specific histologic diagnoses (mean 2.1 +/- 0.84 diagnoses/biopsy) was noted. With increasing time interval to transplantation, single diagnoses as cause of allograft dysfunction decreased. DDS could not reliably differentiate, exclude, or grade any of the common causes of renal allograft dysfunction like vascular and/or cellular rejection, chronic rejection, acute tubular necrosis, cyclosporin nephrotoxicity, relapse of glomerulonephritis and infection. Follow-up studies after established histologic diagnosis in 19 patients with persisting allograft dysfunction demonstrated a lack of sensitivity of DDS to significant superimposed causes of transplant malfunction. We conclude that biopsy is still necessary to direct proper therapy of renal allograft dysfunction.

[Vascular kidney transplant rejection--is a duplex sonographic diagnosis possible?]

The diagnostic value of quantitative Duplex Doppler sonography (DS) in renal allograft evaluation is being viewed increasingly critically. We undertook a retrospective analysis of DS in 51 consecutive patients to assess the capability of DS in the diagnosis of vascular rejection. At the time of renal allograft biopsy, a mean resistive index (RI) was calculated from Doppler measurements within main, segmental, interlobar and arcuate arteries and correlated with histological diagnosis. Our results indicate a low specificity (36% for RI greater than 0.7), low sensitivity (35% for RI greater than 0.9) as well as a low positive predictive value (54% for RI greater than 0.7) for the diagnosis of vascular rejection. Therefore, elevation of the RI is an unspecific finding in different causes of allograft dysfunction. Thus, renal biopsy to establish specific histologic diagnosis of allograft dysfunction remains mandatory.

Transcellular transport and membrane insertion of the C5b-9 membrane attack complex of complement by glomerular epithelial cells in experimental membranous nephropathy

Deposition of the C5b-9 complex of C in glomeruli of rats with experimental membranous nephropathy (MN) is essential for the development of proteinuria. In this investigation C5b-9 was localized in the passive Heymann nephritis (PHN) by immunoelectron microscopy with a mAb specific for C5b-9(m) neoantigen. Its distribution was compared with that in another model of MN induced by successive injections of cationic human IgG and rabbit anti-human IgG into rats. In PHN C5b-9 was found: 1) in the immune deposits (ID), and on the cell membranes of foot processes close to the ID; 2) in clathrin-coated pits of the glomerular epithelial cells (GEC) close to the ID and in membrane vesicles in the cytoplasm, separated from sheep IgG and the gp330 Ag; 3) in high concentration in multivesicular bodies of GEC; and 4) in association with membrane vesicles in the urinary space which presumably are the exocytosed content of membrane vesicular bodies. By contrast, in the cationic IgG-MN model C5b-9 was found mostly in ID, but rarely within the GEC. By freeze-fracture electron microscopy we have further identified 200- to 250-A intramembrane particles in PHN in the cell membranes of the "soles" of the foot processes which resemble membrane inserted human C5b-9(m). Degradation products of C5b-9 were further detected by immunoblotting of a 100,000 x g pellet of PHN rat urine. These results indicate that, in PHN, C5b-9 is inserted into the cell membranes of GEC, and that it is selectively endocytosed and transported across GEC by a cellular mechanism which apparently protects the cell from accumulation of membrane-inserted C5b-9.

Transcellular transport and membrane insertion of the C5b-9 membrane attack complex of complement by glomerular epithelial cells in experimental membranous nephropathy

Deposition of the C5b-9 complex of C in glomeruli of rats with experimental membranous nephropathy (MN) is essential for the development of proteinuria. In this investigation C5b-9 was localized in the passive Heymann nephritis (PHN) by immunoelectron microscopy with a mAb specific for C5b-9(m) neoantigen. Its distribution was compared with that in another model of MN induced by successive injections of cationic human IgG and rabbit anti-human IgG into rats. In PHN C5b-9 was found: 1) in the immune deposits (ID), and on the cell membranes of foot processes close to the ID; 2) in clathrin-coated pits of the glomerular epithelial cells (GEC) close to the ID and in membrane vesicles in the cytoplasm, separated from sheep IgG and the gp330 Ag; 3) in high concentration in multivesicular bodies of GEC; and 4) in association with membrane vesicles in the urinary space which presumably are the exocytosed content of membrane vesicular bodies. By contrast, in the cationic IgG-MN model C5b-9 was found mostly in ID, but rarely within the GEC. By freeze-fracture electron microscopy we have further identified 200- to 250-A intramembrane particles in PHN in the cell membranes of the "soles" of the foot processes which resemble membrane inserted human C5b-9(m). Degradation products of C5b-9 were further detected by immunoblotting of a 100,000 x g pellet of PHN rat urine. These results indicate that, in PHN, C5b-9 is inserted into the cell membranes of GEC, and that it is selectively endocytosed and transported across GEC by a cellular mechanism which apparently protects the cell from accumulation of membrane-inserted C5b-9.