[Thrombotic microangiopathy during urinary tract infection]. / Un caso di microangiopatia trombotica in corso di infezione urinaria.

An 84 year-old woman was admitted because of sepsis, thrombocytopenia, anaemia and acute renal failure that required hemodialysis. The diagnostic tests performed during hospitalization showed a severe urinary tract infection due to Enterococcus faecalis, resulting in mild sepsis. This infection was responsible for acute tubular necrosis and thrombotic microangiopathy, in a clinical context of difficult differential diagnosis and hemolytic-uremic syndrome.

Antiphospholipid antibodies and hypertension.

Hypertension is a common manifestation of antiphospholipid syndrome (APS). Antiphospholipid antibodies (aPL) have been described in patients with hypertension secondary to renal artery stenosis (RAS). Twenty-six patients with RAS and 25 patients with severe essential hypertension (diastolic blood pressure > 110 mmHg or > or = 3 hypertensive drugs) were studied and compared to 61 age- and sex-matched healthy subjects. Serum samples were tested for lupus anticoagulant (LA), anticardiolipin (aCL) IgG and IgM, antiprothrombin (aPT) IgG and IgM, anti-beta2glycoprotein 1 (abeta2GP1) IgG and IgM. aPL were negative in all patients with RAS. Two patients with essential hypertension had positive aPL (8%) (LA in one patient confirmed in a second assay and abeta2GP1-IgG in the other patient confirmed one year later together with aCL IgG positivity). Among healthy subjects, one case (1.6%) was found to be positive for LA, aCL IgM, abeta2GP1 IgM, aPT IgG, aPT IgM. In conclusion, the association between RAS and aPL seems to be casual rather than an expression of an elective thrombotic localization ofAPS. The positive finding of aPL in 8% of patients with essential hypertension, a frequency higher than that of the control population, deserves further studies in larger series to better explore the relationship between aPL and hypertension.

[Biopsy experience at the G. Bosco Hospital from 1996 to 1999]. / Esperienza bioptica dell'Ospedale G. Bosco dal 1996 al 1999.

BACKGROUND: Aim of this study was a retrospective analysis of the renal biopsies performed in our Division. METHODS: Since January 1, 1996 to September 30, 1999 289 biopsies were performed on native kidneys, 90 patients were older than 65. RESULTS: The most frequent nephropathy was IgA glomerulonephritis (IgAGN) (28%), followed by membranous glomerulonephritis (MGN) (11%). In patients older than 65, the most frequent was MGN (20%), followed by IgAGN (12.2%). The total complications were 84 (29.1%) (hematomas >3 cm 1%; blood transfusion: 1.4%). Complications were not related to age, blood pressure, renal function, clinical presentation, number of shots. In 217 patients, the results obtained with two different modalities were compared: manual system (needle size=15 gauge) and automatic system (18 gauge). No statistically significant differences were found as regards the number of shots for single biopsy, number of glomeruli and major complications (1.6% vs 1.3%), while minor complications were more frequent in the second group. CONCLUSIONS: In conclusion, the number of renal biopsies performed in our Division has been increasing year after year. This trend can be partially explained by our wider indications to renal biopsy in elderly population (the data related to resident population showed the greatest prevalence of biopsies in patients 70 to 79 years old). Renal biopsy actually represents a safe examination even in elderly patients. From a technical point of view, on the basis of personal experience, 18 gauge acecut automatic needles seem to be preferred to other kind of devices.

Report on intensive treatment of extracapillary glomerulonephritis with focus on crescentic IgA nephropathy.

UNLABELLED: PURPOSE AND DESIGN OF STUDY: In this retrospective analysis the effects of combined treatment with steroid pulses, cyclophosphamide and plasma exchange on six crescentic IgA glomerulonephritis (IgAGN) patients, selected on a histological basis, were examined. The histological criteria included involvement of more than 40% of glomeruli by cellular crescents. The effects of this treatment were compared to those observed in three untreated crescentic IgAGN patients and 12 treated patients who had extracapillary glomerulonephritis of different origins, i.e. ANCA-associated systemic or renal-limited vasculitis. All patients, except the three crescentic untreated IgAGN patients, received the same 2-month treatment according to a standardized protocol: steroid boli 15 mg/kg methylprednisolone for 3 consecutive days by intravenous infusion, followed by prednisone per os (1 mg/kg/day for 4 weeks, 0.75 mg/kg/day for 4 more weeks), cyclophosphamide per os 2.5 mg/kg/day for 8 weeks, and plasma exchange. RESULTS: After this 2-month course of therapy, substantial clinical improvement was observed in both IgAGN and vasculitis patients. However, a second biopsy revealed that florid crescents persisted in IgAGN patients and, unlike the vasculitis group, during the long-term the initial clinical amelioration disappeared in one-half of the treated IgAGN cases. Nevertheless, even in the progressive cases, intensive treatment seemed to substantially delay the onset of dialysis. CONCLUSIONS: Despite some clinical benefits of therapy, short-term reversal of active crescents appears less likely to occur in crescentic IgAGN than in vasculitis-associated crescentic GN. Intensive treatment seems sufficient to arrest, but inadequate to reverse, phlogistic lesions in IgAGN before development of chronic changes.

Indium-111-labeled granulocyte head accumulation in patients with Wegener's granulomatosis.

Among the symptoms of systemic vasculitis, purulent rhinorrhea with painful sinusitis is thought to be relatively specific to Wegener's granulomatosis (WG). Sixteen patients with rapidly progressive glomerulonephritis (GN), arteritis and extensive crescents in renal biopsy were studied by head indium-111 (111In)-granulocyte scanning. They included 8 WG, 5 microscopic polyarteritis, 2 necrotizing and crescentic GN and 1 classic polyarteritis nodosa. Autologous granulocytes labeled with 12.3 MBq of 111In-oxine were administered intravenously. Scintigraphic studies were performed at 4 and 24 h post-injection. Compared to the non-WG cases, considered as a whole, significant accumulation of tracer in sinuses was observed in WG patients (Fisher's p = 0.02). Substantial scintigraphic amelioration was obtained in a WG case treated with methylprednisolone pulses and, in another WG case, after high doses of intravenous gamma-globulins. The complete disappearance of facial uptake was obtained after 2 months of intensive therapy (i.e., steroid, cyclophosphamide and plasma exchange) in another WG patient. 111In-oxine granulocyte imaging may be useful in clinical practice as an additional marker of disease activity and a tool of identification of upper respiratory tract involvement.

Urinary endothelin in glomerulonephritis patients with normal renal function.

The vasoconstrictor peptide endothelin-1 (ET1) has only recently been characterized and its effects are at present largely speculative. It has been hypothesized that ET1 acts on mesangial cells to cause vasoactive changes which might ultimately contribute to the development of glomerulosclerosis. Opposite to ET1, nitric oxide (NO) inhibits mesangial cell contraction and proliferation. NO activates soluble guanylic acid cyclase and the final product, cyclic GMP (cGMP), has been recently used as a marker of NO action. Urinary levels of ET1 and cGMP were detected in 58 patients with biopsy-proven glomerulonephritis (GN), including 36 IgA nephropathy (IgAGN), 30 with normal and 6 with impaired renal function, 10 patients with non-IgA mesangial GN and 12 pts with membranous GN (MGN) with normal renal function. Compared to normal controls (0.019 +/- 0.006 ng/min), urine ET1 levels were significantly higher in patients with normal renal function having IgAGN (0.035 +/- 0.017, p < 0.01), MGN (0.028 +/- 0.013, p < 0.05), non-IgA mesangial GN (0.027 +/- 0.012, p < 0.05) and those with IgAGN and renal failure (0.032 +/- 0.011, p < 0.01). However no difference was found between MGN patients and normals by deleting MGN cases with mild to moderate mesangial proliferation. The mean value of urinary cGMP in IgAGN patients with renal failure (0.186 +/- 0.117 nmol/min) was lower (p < 0.05) than that of each group with normal renal function (IgAGN: 0.378 +/- 0.010 nM/min; MGN: 0.338 +/- 0.064 nmol/min, non-IgAGN: 0.436 +/- 0.168 nmol/min). The same significant differences were obtained by correcting cGMP values for creatinine urinary excretion. Urinary ET/cGMP ratio (assumed as an index of the relative balance between vasoconstrictor and vasorelaxing factors) was found to be higher than normal (0.570 +/- 0.010 ng/nmol) both in IgAGN patients with normal renal function (0.103 +/- 0.064 ng/mol, p < 0.05), and in those with renal failure (0.203 +/- 0.108 ng/nmol, p < 0.02). Urinary cGMP values were not related to plasma levels of atrial natriuretic peptide (ANP). These data show that hyperexcretion of ET1 occurs in a number of patients with mesangial proliferative GN. In some of them, mainly those with established glomerular damage, the local production of ET1 is not counter-balanced by adequate cGMP biosynthesis.

Colour-coded Doppler sonography in monitoring native kidney biopsies.

Two hundred and one patients had biopsies of their native kidneys with ultrasound-guided needle technique. They were evaluated on the second post-biopsy day with colour-coded Doppler sonography. Ten patients out of these 201 were found to have an arteriovenous fistula, which remained asymptomatic for the whole follow-up period (follow-ups ranged from 2 to 31 months). Four of these 10 patients developed a perirenal haematoma as well and five macroscopic haematuria. Our study shows that the systematic use of colour-coded Doppler sonography after renal biopsy facilitates diagnosis of arteriovenous renal fistula.

Removal systems of immunoglobulin A and immunoglobulin A containing complexes in IgA nephropathy and cirrhosis patients. The role of asialoglycoprotein receptors.

BACKGROUND: Whereas the complex removal routes hypothesized for IgA containing immune complexes (IC) and macromolecules can be adequately analyzed by a recently proposed IgA1-IgG aggregate probe (Lab Invest, 66: 86-95), the relative significance of the asialoglycoprotein receptors in IgAIC clearance is still uncertain. EXPERIMENTAL DESIGN: The removal kinetics of 99mTc diethylenetriamine-pentaacetic acid-conjugated asialo alpha 1 acid glycoprotein (AAGP) and 123I-labeled IgA1-IgG aggregate were analyzed in 11 cirrhosis patients and 13 IgAN patients of comparable age. RESULTS: IgA1-IgG aggregate mean plasma clearance rate was delayed in IgA neuropathy (IgAN) patients (slope 0.038 minutes-1, range 0.027 to 0.053) compared with normals (0.047 minutes-1, range 0.038 to 0.053, p = 0.05). The liver was the main organ involved in the IgA1-IgG removal. When compared with normals, (34.3 minutes, range 29.8 to 42.2), the liver mean transit time (MTT) was significantly (p < 0.02) prolonged in IgAN patients (41.3 minutes, 33.6 to 52.3). Participation of spleen in clearance was observed in some patients and was almost invariably concurrent with normal clearance parameters. Conversely, 9 out of 11 cirrhosis patients had a remarkable splenic uptake, but the blood clearance rate was invariably delayed (0.022 minutes-1, 0.014 to 0.028, p < 0.003) and liver MTT extremely prolonged (122.4 minutes, 52.4 to 400, p < 0.003). In IgAN patients with delayed clearance of the IgA1-IgG aggregate, a distinct trend of progression towards renal failure was noted. AAGP clearance was also delayed in cirrhosis patients: slope = 0.166 minutes-1, 0.108 to 0.247, p = 0.05 as compared with both normals (0.230, 0.173 to 0.289) and IgAN patients (0.250, 0.184 to 0.254). Liver MTT in cirrhosis patients was extremely prolonged: 240.6 minutes, 132.5 to 400 minutes, p < 0.007 compared with both normals (90.0 minutes, 82.7 to 96.6) and IgA patients (92.2 minutes, 70.3 to 107.1). AAGP clearance parameters in normals and IgAN patients were not statistically different. MTT values of AAGP and IgA1-IgG aggregate were strictly related (p = 0.008), suggesting that asialoglycoprotein receptors are partially involved in the clearance of the IgA1-IgG aggregate probe. CONCLUSIONS: Some patients with IgAN have a prolonged circulation of an IgAIC miming probe, probably due to an impaired macrophage function. Other possibilities of prolonged circulation of IgAIC in these patients should imply an abnormal IgA glycosylation pattern that allows IC to escape from an effective asialoglycoprotein receptor system. In cirrhosis patients, all of the removal routes of IgA and IgA containing IC are greatly altered suggesting a causative role in the development of an associated, often clinically inapparent, glomerular disease.

Role of monocytes in cryoglobulinemia-associated nephritis.

Several monocyte-macrophage functions were found to be defective in cryoglobulinemic patients. Nevertheless, monocytes actively phagocytizing cryoglobulins have been frequently found in kidney specimens from these patients. Whether subsequent degradation of the ingested immune material is effective, however, is still unknown. Monocytes from eight cryoglobulinemic patients (4 with active disease and associated nephritis and 4 inactive cases without nephritis) and eight normal controls of same sex and similar age were analyzed. Monocytes from patients with active cryoglobulinemia and associated nephritis were found to be able to ingest, but unable to catabolize, cryoglobulins, as shown by electron microscopy using gold-labeled goat IgG to human IgG and IgM in 18-hour cultured suspensions. Synthesis and maturation of monocyte cathepsin D, one of the most important lysosomal proteases, were analyzed in the same subjects. Purified monocytes were cultured in presence or absence of cryoglobulins for 18 hours at 37 degrees C in RPMI medium and labeled with 35S-methionine. The various forms of cathepsin D were separated by electrophoresis and visualized by fluorography. Results from cultures of monocytes from clinically active cryoglobulinemic patients with nephritis suggest that intracellular transport of newly synthesized cathepsin D was impaired and the release into the medium of precursor polypeptides of the enzyme enhanced in each experimental condition. Since procathepsin D is susceptible to activation in pathologic conditions lowering local pH (such as in inflamed tissues), these data suggest that monocytes from patients with active cryoglobulinemia and associated nephritis have a propensity to exert phlogistic effects via secretion of procathepsin D in tissues.

Serum and intracellular detection of cytokines in patients undergoing chronic hemodialysis.

Tumor necrosis factor (TNF) was detected, before and after dialysis, in sera from 69 patients and, at various times during dialysis, in 28 patients carefully selected for the absence of intercurrent illness. Blood samples were also sequentially collected for separation of monocytes, and cells were sonicated to detect intracellular TNF. Compared with serum levels obtained from 41 healthy subjects, basal TNF values of the unselected group of 69 patients were significantly higher (p < 0.01), independent of the dialyzer membrane. A significant increase in TNF levels by the end of dialysis was found only with Cuprophan (p < 0.01). In the selected group of 28 patients, no significant changes in TNF values were observed in sequential samples. However, a significant increase of intramonocyte TNF levels was found in Cuprophan patients (p < 0.025). Soluble interleukin-2 receptor (IL-2R) levels, measured in parallel in sera from unselected and selected patients, were found to be very much higher than healthy controls without significant changes during the dialysis procedure. While the diverse profiles of TNF obtained from differently selected patients suggest that mechanisms other than membrane biocompatibility play a role in the appearance of these low cytokine levels, the possible nature of uremic toxin for soluble IL-2R can be envisaged by detection in dialysis patients.

Kinetics and fate of IgA-IgG aggregates as a model of naturally occurring immune complexes in IgA nephropathy.

The characteristic granular IgA immunofluorescent pattern in the kidneys of IgA nephropathy patients is consistent with immune complex pathogenesis. The possibility of a delayed clearance of IgA-containing immune complexes from circulation in IgA nephropathy patients is still under discussion. Since pure IgA immune complexes are probably nonphlogistic, (in contrast to IgG-containing IgA immune complexes), the in vivo clearance of a mixture of heat-aggregated IgA/G purified from pooled human sera was analyzed. The test probe was efficiently labeled with 123I and the time course of radioactivity was measured by a gamma-camera. Both the liver and the spleen were found to be involved in the disappearance of IgA/G complexes. Liver accumulation, which was markedly predominant, closely approximates a gamma-variate function which allowed determination of a mean transit time of 34.37 minutes, range 29.8 to 42.2, in 8 normal and 37.54 minutes, range 30.9 to 50.7 in 17 patients (p less than 0.04). At 2 hours, segmental gut accumulation was found, which demonstrated removal by hepatobiliary system as well. Compartmental analysis in patients indicated 3 major compartments represented by vascular bed, hepatobiliary and reticuloendothelial systems (including both liver and spleen phagocytes). Blood clearance rate, representing the final result of multiorgan removal of the test probe from the blood stream, was found to be significantly delayed in IgA nephropathy patients with a slope (0.035 min-1, range 0.019 to 0.052) significantly less negative compared with controls (0.047 min-1, range 0.038 to 0.053, p less than 0.01). This test probe was able to reproduce both removal routes (macrophages cells and hepatobiliary system) hypothesized for IgA-containing immune complexes in humans.

The fate of aggregated immunoglobulin A injected in IgA nephropathy patients and healthy controls.

Organ uptake of IgA-containing immunologically active material was studied in humans by intravenous (IV) injection of 131I-labeled heat-aggregated human secretory IgA (HAS-IgA) in nine patients affected by primary IgA nephropathy and 10 normal volunteers. Aggregated secretory IgA was found to be removed almost exclusively by the liver. The peak activity in liver was reached at 21.1 minutes (range, 18 to 26 minutes) in patients and 19 minutes (range, 14 to 22 minutes) in controls. The rate of increase of liver radioactivity was found to be significantly slower in patients (with a mean slope of 5.0; range, 3.4 to 7.1 v 7.6, 5.6 to 11.4; P less than 0.02). The mean liver to precordium ratio at the peak time was significantly lower in patients (mean value, 2.3; range, 1.9 to 3.1) compared with controls (mean value, 3.3; range, 2.4 to 4.0) (P less than 0.02). These data confirm the pivotal role of the liver in the removal of aggregated IgA in humans and the defective clearance capacity of this test probe in IgA nephropathy patients.

Influence of gluten-derived fractions on chemiluminescence production by human neutrophils.

The effects of gliadin and glyc-gli on leukocyte chemiluminescence response were assessed in vitro. A dose-dependent increase in chemiluminescence response of neutrophils stimulated by zymosan was observed by using gliadin at concentrations ranging between 1 and 20 micrograms. By increasing glyc-gli concentration, a bimodal response was observed with an enhancement up to 50 micrograms/ml, followed by suppressive effects, which were again dose-dependent. The possible implications of these findings in human pathology are discussed.

Wheat protein antigens and effector cells of aspecific immunity.

The effects of gliadin and glyc-gli on leukocyte chemiluminescence response, cytotoxic activity and locomotion were assessed in vitro. A dose-dependent increase in chemiluminescence response of neutrophils stimulated by Zymosan was observed by using gliadin at concentrations ranging between 1 and 20 micrograms. By increasing glyc-gli concentrations, a bimodal response was observed with an enhancement up to 50 micrograms/ml, followed by dose-dependent suppressive effects. The cytotoxic activity of a suspension of peripheral blood mononuclear cells on the human myeloid line K562 was assessed in a Chromium release assay. By pretreating effector cells with optimal doses of gliadin (5 micrograms/ml) or glyc-gli (50 micrograms/ml), an enhancement of cytotoxic activity, similar to that of the gamma-Interferon, could be achieved. Finally glyc-gli was found to elicit neutrophil chemokinesis. The possible implications of these findings in diseases characterized by gluten intolerance are discussed.

Effects of a gluten-free diet in primary IgA nephropathy.

In an uncontrolled study a gluten-free diet was given to 29 patients affected by primary IgA nephropathy (IgAGN). All of them followed the diet for 6 months, 23 patients for 1 year and 9 for 2 to 4 years. Mean levels of IgA containing circulating immune complexes (IgAIC), detected by a specific conglutinin assay and by measuring IgA content in 2.5% polyethylene glycol precipitates, on an unrestricted diet, significantly decreased after 6 months of gluten-free diet (p less than 0.01) and remained reduced during the follow-up. A decrease in IgAIC levels was evident in 85.7% of the cases with basal positive data, with complete normalization in 64.3% of them. IgA to gluten antigens (ethanol- or saline-soluble gliadin, glutenin and the lectin fraction termed glyc-gli) as well as to heterologous bovine and egg albumins were found to be significantly increased on an unrestricted diet in the group of 14 IgAGN patients with basal positive IgAIC. The mean levels of IgA to most dietary antigens significantly decreased after 6 months to 1 year of a gluten-free diet. A decrease in IgA to ethanol-soluble gliadin was evident in 81.8% of the cases with basal positive data, with complete normalization in 63.6%. A subgroup of 27.5% of IgAGN patients showed positive IgAIC values associated with increased IgA values to a variety of dietary antigens. A gluten-free diet induced in 75% of the cases a parallel improvement in these abnormal immunological data. Mean proteinuria values were found to be significantly decreased after 6 months of the diet and a reduction was also observed in microscopic hematuria. However, mean blood creatinine levels showed a significant increase after the gluten-free diet. The data of this study indicate that a gluten-free diet can modify some immunological abnormalities in a group of IgAGN patients, reducing levels of IgAIC and IgA to dietary antigens. The clinical course does not seem to be favorably influenced, since a relentless progression towards renal failure was observed.