Genome-wide association analyses define pathogenic signaling pathways and prioritize drug targets for IgA nephropathy

IgA nephropathy (IgAN) is a progressive form of kidney disease defined by glomerular deposition of IgA. Here we performed a genome-wide association study of 10,146 kidney-biopsy-diagnosed IgAN cases and 28,751 controls across 17 international cohorts. We defined 30 genome-wide significant risk loci explaining 11% of disease risk. A total of 16 loci were new, including TNFSF4/TNFSF18, REL, CD28, PF4V1, LY86, LYN, ANXA3, TNFSF8/TNFSF15, REEP3, ZMIZ1, OVOL1/RELA, ETS1, IGH, IRF8, TNFRSF13B and FCAR. The risk loci were enriched in gene orthologs causing abnormal IgA levels when genetically manipulated in mice. We also observed a positive genetic correlation between IgAN and serum IgA levels. High polygenic score for IgAN was associated with earlier onset of kidney failure. In a comprehensive functional annotation analysis of candidate causal genes, we observed convergence of biological candidates on a common set of inflammatory signaling pathways and cytokine ligand-receptor pairs, prioritizing potential new drug targets.

[Membranous glomerulonephritis with crescent overlapping]

Acute crescentic transformation is a rare but well described event in patients with membranous glomerulonephritis. We report our experience with a 66-year-old Caucasian man presented for rapid decline in renal function. For nearly 10 years, he was suffering from hypertension and mixed sensori-motor polyneuropathy. He performed therapy with prednisone and azathioprine, suspended 1 year before presentation. Moreover, six months before presentation, laboratory tests showed a serum creatinine concentration 220 mol/L and a 24-h protein excretion 0,75 g/d. The physical examination showed oedema and severe hypertension; the 24-h protein excretion was 1,1 gr/d and creatinine concentration was 550.8 mol/L; ANCA and other immunological tests were negative. There was no evidence of SLE, infection or malignancy. The kidney biopsy highlighted a membranous GN with crescentic overlap. The patient was treated with steroid and cyclophosphamide. Because there was no sign of improvement after 2 months, we stopped the cyclophosphamide therapy and the patient started chronic haemodialysis treatment. Unlike membranous nephropathy, patients with superimposed crescentic glomerulonephritis appear to have a more aggressive clinical course. The importance of recognizing this group of patients with membranous nephropathy and crescentic glomerulonephritis is that immunosuppressive therapy may ameliorate the progression of renal damage and in some cases early treatment was associated with useful recovery of renal function.

[Renal involvement in Erdheim-Chester disease]

The Erdheim-Chester disease is a rare form of Langherans cells. Since 1987 it is distinguished from other istiocytosis previously identified. The diagnosis of the disease relies on defined radiological (bone imaging) and pathological (histiocytic infiltration) criteria. Bone disease is crucial but systemic manifestations are reported more frequently at onset. Renal involvement is always asymptomatic at onset of disease or in the follow-up. In this review we analyze the reports of the literature; we highlight 3 pathological mechanisms of renal involvement: renal and retroperitoneal infiltration, urinary tract obstruction, renal arteries stenosis. No treatment to date has demonstrated an improvement in survival of patients with EC. Renal involvement is therefore symptomatic (ureteral stenting, percutaneous nephrostomy) or is adopted a wait-and-see attitude.

Kidney involvement in a Wegener granulomatosis case

Wegener Granulomatosis is a systemic Anti-Neutrophil Cytoplasmic Autoantibody-associated Vasculitis, affecting small-to-medium vessels. Clinical presentation with simultaneous involvement of kidney and upper and lower respiratory tract is unusual. We report an instructive case of WG, analyzing clinical course, laboratory, and radiological features, kidney, lung, and larynx histological pictures. Besides renal biopsy, nephrology team performed larynx and lung biopsies because of unusual clinical presentation, computed tomography chest examination, and relevant malignancy risk regarding following immunosuppressant therapy.

Natural history of honeycombing: follow-up of patients with idiopathic pulmonary fibrosis treated with single-lung transplantation

PURPOSE

Although honeycombing is one of the key features for the diagnosis of idiopathic pulmonary fibrosis (IPF), its origin and evolution are still poorly understood. The aim of our study was to analyse the natural history of honeycombing in patients treated with single-lung transplantation.

MATERIALS AND METHODS

We considered seven patients who underwent single-lung transplantation; two of them (28.6%) were excluded from our analysis because they died in the posttransplantation period, whereas the remaining five (71.4%) were evaluated with computed tomography (CT) over 67.6±38.56 months. Each CT scan was assessed for disease extension and cyst size (visual score and size of target cysts); CT scans acquired after 2006 were also assessed for native lung volume.

RESULTS

All patients showed disease progression (with a concurrent reduction in lung volume in two, 40%) and a progression of honeycombing, with increased number and size of cysts in four (80%). We observed dimensional changes in all target cysts (enlargement or reduction); three patients (60%) also had radiological evidence of complications, such as spontaneous rupture with pneumothorax and development of mycetomas within the cysts.

CONCLUSIONS

Honeycombing is a dynamic process in which the overall trend is represented by a dimensional increase in cystic pattern; however, single cysts may have a different evolution (enlargement, reduction or complications). This behaviour could be explained by the variety of the pathogenetic processes underlying honeycombing, with cysts that may present abnormal communication with the airway, including the development of a check-valve mechanism.

Incidence of hepatitis C virus infection in patients with chronic kidney disease on conservative therapy

Hepatitis C virus (HCV) infection is a never-ending public health problem. Many studies have investigated the incidence of HCV infection among dialysis patients, but there have only been a few epidemiological studies in renal conservative therapy. We studied 320 subjects with pre-dialysis chronic kidney disease living in Sicily, Italy. The incidence of HCV infection was 6.25%. In Europe, incidence ranges from 0.2% to 3.5%. It appears that the incidence of HCV infection is higher in the studied patient population than in the population as a whole.

[Nephrotic syndrome and Gram-negative sepsis in a patient with strongyloidiasis: a case report]

Strongyloidiasis is caused by a small intestinal nematode with a complex life cycle. In Italy the infection is endemic in rural areas of the Po Valley. The clinical syndrome of S. stercoralis encompasses a broad spectrum of symptoms and signs and, in the immunocompromised host, larvae can migrate to different organs and tissues. Also immune response seems to play a role in the pathogenesis of the disease. We report a case of strongyloidiasis complicated by Gram-negative sepsis and nephrotic syndrome in an immigrant from South America with a normal immune response. Whereas sepsis cleared up quickly, parasitic clearance was obtained only after treatment with ivermectin and nephrotic syndrome was still present three months after the end of treatment.

[Treatment of lupus nephritis]

SLE begins with renal symptoms in about 30-50% of the patients and after 10 years over 70% of them has complications. In the last years the medical therapy improved the outcome of SLE and its complications. Presently, the survival for lupus nephritis is 80% after five years. The nephritis treatment is divided into remission-inducing treatment that is followed by remission-maintaining treatment. Moreover, it is considered the therapy for preventing or reducing toxic and side-effects from drugs and the therapy for flare-ups. To initiate the specific therapy is important to consider the histological class (WHO). In the remission-inducing treatment steroids are used alone for 3-6 months in class IIB or in association with cyclophosphamide in classes III-IV and V and for flare-ups. For remission-maintaining treatment steroids are used in association with azathioprine. The drugs improved the outcome of nephritis but produced side-effects that determined the suspension of the drug and/or reduction of dosage and/or the use of other drugs like mycophenolate mofetil or rituximab.

Prevalence of drug resistance and newly recognised treatment-related substitutions in the HIV-1 reverse transcriptase and protease genes from HIV-positive patients naïve for anti-retrovirals

The aim of this study was to assess the prevalence of genetic changes in either the HIV reverse transcriptase (RT) or protease (Pro) genes in a cohort of patients naïve for anti-retroviral therapy. Of 61 patients, 43 (70.5%) were infected with HIV strains harbouring at least one resistance-related mutation, with 41 (67.2%) harbouring newly recognised treatment-related mutations. Among the 61 patients, the prevalence of specific mutations in the RT gene was as follows: 39A, 1.6%; 43E, 1.6%; and 228H, 1.6%. The prevalence of specific mutations in the Pro gene was as follows: 11I, 1.6%; 13V, 26.2%; 35D, 19.6%; 45R, 1.6%; 58E, 1.6%; 62V, 31%; 72V, 11.4%; 72M, 6.5%; 72T, 3.2%; 75I, 1.6%; and 89M, 13%. A higher prevalence of newly recognised mutations was found in strains from patients infected through sexual practices (30/36 = 83.4% vs. 11/25 = 44%; p 0.0023; OR 10.91; 95% CI 3.14-40.39). These findings support the use of resistance testing in patients naïve for anti-retroviral therapy, and suggest that the possible impact of newly recognised treatment-related mutations on clinical outcome requires further investigation.

Double diagnostic meaning of serum transferrin receptor in hemodialysis patients: two case reports

Hemodialysis patients on maintenance erythropoietin need an adequate supply of iron to optimize therapy and achieve and maintain target levels of hemoglobin. Evaluation of iron stores and early detection of iron deficiency are essential for management of erythropoiesis in chronic renal failure, but there is still no single biochemical or hematological parameter that is sensitive or specific enough to completely describe the distribution of iron in the body. Serum transferrin receptor (sTfR) is a marker of iron that is available for erythropoiesis. We selected 2 clinical cases in which hemodialysis patients were receiving maintenance erythropoietin. To suggest how sTfR can be used in its double diagnostic meaning according to the clinical context of the patient, sTfR was evaluated in one case as a marker of iron deficiency and in the other as a marker of erythropoiesis. The association of sTfR with hematological parameters of iron-deficient erythropoiesis (reticulocyte hemoglobin content, percentage of hypochromic erythrocytes, ratio of reticulocyte hemoglobin content to hemoglobin content) and parameters of stimulated erythropoiesis (absolute reticulocyte count, immature reticulocyte fraction) increases the accuracy of sTfR in its double diagnostic power.

A 10-year survey of Mycobacterium tuberculosis isolates in Pavia and their drug resistance: a comparison with other Italian reports

A retrospective review was made of the bacteriological and medical records of patients with culture-confirmed pulmonary tuberculosis who attended the IRCCS San Matteo Polyclinic of Pavia, between 1990 and 2000. Altogether, 279 patients were included in the survey: 220 new cases and 59 prior treatment cases. Resistance to at least one drug, and resistance to both isoniazid and rifampicin (MDR) were more common among previously treated patients than among new cases (86.4% vs. 34.1%, and 44% vs. 5.9%, respectively). While the frequency of resistance to any drug showed no variation in the period examined, a trend toward a progressive decrease in the frequency of primary MDR-TB was observed (from 11.9% in 1990-1992 to 1.3% in 1998-2000). The level of resistance observed in our study suggests that all isolates of Mycobacterium tuberculosis should be tested for drug susceptibility, especially when obtained from patients who report a previous episode of the disease.

Bactericidal activity of Pistacia lentiscus mastic gum against Helicobacter pylori

In this study we evaluated the antibacterial activity of mastic gum, a resin obtained from the Pistacia lentiscus tree, against clinical isolates of Helicobacter pylori. The minimal bactericidal concentrations (MBCs) were obtained by a microdilution assay. Mastic gum killed 50% of the strains tested at a concentration of 125 microg/ml and 90% at a concentration of 500 microg/ml. The influence of sub-MBCs of mastic gum on the morphologies of H. pylori was evaluated by transmission electron microscopy. The lentiscus resin induced blebbing, morphological abnormalities and cellular fragmentation in H. pylori cells.

The very long-term prognosis and complications of lupus nephritis and its treatment

Although the short- and medium-term (5-10 years) outcome of patients with lupus nephritis has been studied extensively, there are very few data on the second and subsequent decades. We studied outcome in 110 local patients investigated at a single centre before 1986, who all had potential follow-up of more than 10 years (actual 2-31 years, median 15.5 years). At last follow-up, 40 patients were dead and 70 alive, nine of whom were on maintenance dialysis or transplanted, actuarial survivals being 84%, 72%, 62%, 61% and 54% at 5, 10, 15, 20 and 25 years for the group as a whole. Survival was better in the cohort 1976-86 (n = 60) than in that from 1963-75 (n = 50) (90, 81 and 76% vs. 78, 56 and 43% at 5, 10 and 15 years, p < 0.001). Sepsis (12) and myocardial infarction (8) were the principal causes of death. Of living patients with renal function, 38% had normal urine and renal function, 11 were off all treatment (19%), 62% had persistent proteinuria and 18% had reduced but generally stable renal function. Renal failure, in those patients who developed it, occurred during the first decade and none of 67 patients actually followed more than 10 years subsequently went into renal failure. Induction treatment was with prednisolone, combined with azathioprine in more severe forms of nephritis, and from the middle 1970s to 1986, 30 with methylprednisolone and in 12 cases plasma exchange. Seventeen other patients were treated using oral cyclophosphamide during the 1960s. No patient received i.v. cyclophosphamide as induction therapy, although nine patients had this form of treatment later, largely because of non-compliance. Serious complications of lupus and/or its treatment occurred in 49%: sepsis in 32, ischaemic heart disease in 20, thrombosis in one and avascular necrosis of bone in eight. In contrast, fracturing osteoporosis occurred in only three, and cataracts requiring surgery and diabetes mellitus in none. The very long-term outlook of lupus nephritis, especially its more severe forms, has improved, but that with current management strategies only a minority of patients are able to stop treatment altogether, and the incidence of serious complications is high.

Rapid identification of Mycobacterium tuberculosis and Mycobacterium avium by polymerase chain reaction and restriction enzyme analysis within sigma factor regions

A single Polymerase Chain Reaction (PCR) within the rpoV gene was developed to rapidly distinguish mycobacteria isolated from clinical specimens. The species identifications of Mycobacterium avium complex (MAC) and Mycobacterium tuberculosis were congruent with standard typing techniques. The analysis was targeted toward the identification of species-specific markers for the clinically relevant M. tuberculosis and M. avium. In addition, HaeIII digestion of the amplification products yielded isolates-specific bands.

Multicenter comparison of ESP Culture System II with BACTEC 460TB and with Lowenstein-Jensen medium for recovery of mycobacteria from different clinical specimens, including blood

The recently developed ESP Culture System II (AccuMed, Chicago, Ill.) was compared with radiometric BACTEC 460TB (Becton Dickinson, Towson, Md.) and with Lowenstein-Jensen medium for recovery of mycobacteria from over 2,500 clinical specimens both of respiratory and nonrespiratory origin, including blood. The majority of the 219 mycobacterial isolates (129) belonged to the Mycobacterium tuberculosis complex, followed by 37 isolates of the Mycobacterium avium complex (MAC) and 53 isolates of eight other mycobacterial species. Rates of recovery obtained with BACTEC, ESP, and Lowenstein-Jensen medium were 89, 79, and 64%, respectively, with such differences being statistically significant. Different media and systems appeared to behave differently when the more frequently detected organisms were considered: M. tuberculosis complex isolates grew better with BACTEC, and MAC isolates grew better with ESP. An analysis of the combinations of Lowenstein-Jensen medium with BACTEC and with ESP did not reveal significant differences in recovery rates. With regard to the times needed for the detection of positive cultures, they were significantly longer on Lowenstein-Jensen medium (average, 28 days) than with the remaining two systems, between which there was no difference (average, 18 days). We conclude, therefore, that the ESP system, when used in combination with a solid medium, performs as well as the thoroughly validated radiometric BACTEC system and offers the advantages of full automation and absence of radioisotopes.

Rapid drug susceptibility of Mycobacterium avium complex using a fluorescence quenching method

Mycobacteria Growth Indicator Tube (MGIT) is a recently introduced rapid growth detection method which uses an oxygen quenched fluorescent indicator. The present study evaluated the ability of this new method to determine the drug susceptibility of Mycobacterium avium complex (MAC). Thirty strains recovered from patients with AIDS were tested for susceptibility to clarithromycin, rifabutin, ciprofloxacin, azithromycin and amikacin using MGIT. Results were compared to susceptibilities determined by the agar dilution method. The results obtained showed a 100% correlation between MGIT and the agar dilution method for rifabutin and clarithromycin. There was a 100% correlation between the two methods for azithromycin against 27 strains. MGIT was well correlated with the agar dilution method for detecting resistance to clarithromycin, rifabutin and azithromycin in 4 days, but the correlation was poor when susceptibilities to ciprofloxacin and amikacin were determined. This rapid method is non-radiometric, noninvasive and does not require any special instruments.

Isolation of the newly described species Mycobacterium celatum from AIDS patients

Mycobacterium celatum is a recently described species which, on the basis of conventional tests, may be misidentified as Mycobacterium xenopi or as belonging to the Mycobacterium avium complex. Only genomic sequencing or high-performance liquid chromatography of cell wall mycolic acids can presently allow a correct identification of this mycobacterium. Two cases of infection due to M. celatum, in AIDS patients, are described here. The quantitative susceptibility pattern of the isolates to a wide spectrum of drugs is also reported.

Lactobacillus casei endocarditis in an intravenous heroin drug addict: a case report

A 24-year-old HIV negative unemployed intravenous heroin addict with teeth in poor condition was admitted to hospital with left hemiparesis; CT scan of the brain revealed a hypodense area in the right parietal region. He was apyrexial with marked leukocytosis and raised ESR, had an aortic diastolic murmur and an echocardiogram showed marked aortic insufficiency with possible small vegetations on the anterior leaflet of the mitral valve. Lactobacillus Casei was isolated from repeated blood cultures. Therapy with penicillin G together with netilmicin for 6 weeks led to improvement of his clinical status and an echocardiogram on discharge showed clear improvement. Regression of the cerebral lesions was also demonstrated on CT scan. We conclude that lactobacillus species should be sought in all haemoculture negative endocarditis in the presence of tooth disease.

Serum bactericidal activity against aerobes and anaerobes of volunteers receiving cefoxitin or cefotetan

Six volunteers received intravenously a single 1 g dose of cefoxitin or cefotetan. The 2 groups were crossed after a week of washout. Five strains each of Escherichia coli, Klebsiella pneumoniae, Bacteroides fragilis and Bacteroides thetaiotaomicron susceptible to the administered drugs were tested for serum bactericidal activity (SBA). Blood samples were obtained before and 0.5, 3.0 and 12.0 hours after antibiotic injection. SBA was determined using microtitre procedures. Anaerobic bacteria were incubated in an anaerobic chamber. Cefotetan showed a very high SBA both against aerobes and anaerobes over the 12 hour sampling time. Cefoxitin reached satisfactory SBA values only 0.5 hours after administration.