Renal Disease in Madeira Islands: Twenty-Seven Years' Experience of Native Kidney Biopsies

Introduction: Renal biopsy plays an essential role either in the diagnosis or in the prognosis of patients with renal disease. In order to assess its epidemiology and evolution in Madeira Islands, we analysed twenty-seven years of native kidney biopsies. Methods: We performed a retrospective analysis of clinical records, including histological revision from 1986 to 2012, totalling 315 native kidney biopsies. They were assessed regarding the temporal evolution both for the quality/indications for renal biopsy and for the patterns of kidney disease. Results: A total of 315 native kidney biopsies were analysed. The patients’ mean age was of 40.8 ± 18.4 years and 50.5%(n = 159) were males. The most common indications for renal biopsy were nephrotic syndrome (36.2%, n = 114) and acute kidney injury (20.0%, n = 63). Among primary glomerular diseases (41.5%, n = 115) the most common were IgA nephropathy (26.1%, n = 30) and focal-segmental glomerulosclerosis (17.4%, n = 20) and among secondary glomerular diseases (31.4%, n = 87), lupus nephritis (51.7%, n = 45) and amyloidosis (20.7%, n = 18). Statistical analysis revealed significant correlation between gender and major pathological diagnosis (Fisher’s exact test, p <.01) and between indications for renal biopsy and major pathological diagnosis (χ2, p <.01). Regarding the temporal evolution, no statistically significant differences were found in the number of renal biopsies (χ2, p =.193), number of glomeruli per sample (Fisher’s exact test, p =.669), age (Kruskal-Wallis, p =.216), indications for renal biopsy (χ2, p =.106) or major pathological diagnosis groups (χ2,p =.649). However, considering the specific clinico-pathological diagnoses and their temporal variation, a statistically significant difference (Fisher’s exact test, p <.05) was found for lupus nephritis and membranous nephropathy with an increasing incidence and for amyloidosis with an opposite tendency. Discussion: The review of the native kidney biopsies from a population with particular characteristics, geographically isolated, such as those from Madeira Islands, showed parallel between epidemiological numbers referring to other European subpopulations, allowing simultaneously a comprehensive approach to our renal biopsy policies.

Treatment of Hepatitis C Virus Infection in Kidney Transplant Recipients: Case Report

Chronic hepatitis C virus (HCV) infection exists in a large proportion of patients undergoing renal transplantation. Nowadays it is not considered to be an absolute contraindication to transplantation; however, it is associated with an increased risk for the patient and accounts for a shorter half-life of the renal allograft. We present three transplant recipients who displayed serious hepatic dysfunction after renal transplantation due to an HCV infection. In two of these cases, the liver biopsies established the diagnosis of FCH. In the third case, the liver biopsy was compatible with the early stages of FCH. All patients were started on peg-interferon alfa 2-b and ribavirin with subsequent normalization of hepatic function and early complete viral responses.

Specificity and Sensitivity of Screening for Anti-HLA Antibodies in Kidney Allograft Dysfunction

BACKGROUND: Prospective testing for posttransplant circulating anti-HLA antibodies seems to be a critical noninvasive tool, but confirmatory data are lacking. MATERIALS AND METHODS: Over the last 3 years, peritubular capillary (PTC) C4d deposition was prospectively sought by an immunofluorescence technique applied to frozen tissue in biopsies obtained for allograft dysfunction. Screening for circulating anti-HLA class I/II alloantibodies (AlloAb) by the flow cytometric test was performed simultaneously. RESULTS: We evaluated 132 sets of biopsies and simultaneous serum samples. PTC C4d deposition was demonstrated in 15.9% (21/132) of biopsies. Circulating anti-HLA I/II AlloAb were detected in 25% (33/132) of serum samples. Employing receiver-operator characteristic (ROC) curves for all C4d-positive biopsies, screening for AlloAb showed a global specificity of 82% and sensitivity of 61.9%. When this analysis was restricted to biopsies obtained in the first month posttransplantation, the sensitivity increased to 81.8%, but the specificity decreased to 76.9%. After the first month posttransplantation, we observed sensitivity of 40.0% and a specificity of 86.4%. In the first month posttransplantation, all patients with a diagnosis of acute antibody-mediated rejection displayed circulating anti-HLA class I/II, but not always at the same time as the C4d-positive biopsy. CONCLUSIONS: In the first month posttransplantation, prospective monitoring of anti-HLA antibodies may be useful. The high sensitivity allows the identification of patients at risk, affording an earlier diagnosis of antibody-mediated rejection. After the first month, the test can be used to evaluate allograft dysfunction episodes, since positivity is highly suggestive of an antibody-mediated process.

Leukopenia in Kidney Transplant Patients with the Association of Valganciclovir and Mycophenolate Mofetil

Cytomegalovirus (CMV) is the most common viral infection after transplantation. Valganciclovir (VGC) is established for prophylaxis and treatment of CMV infections, but leukopenia which appears in 10% to 13% (severe in 4.9%) is the principal side effect. We have recently noted an increased incidence of leukopenia and severe neutropenia among our renal transplant patients and thought to identify the associated factors. We conducted a retrospective analysis of all kidney transplantations performed between January 2005 and December 2006. All patients received mycophenolate mofetil (MMF), tacrolimus, and steroids. VGC was used for targeted prophylaxis and preemptive therapy of CMV infection, with doses adjusted to renal function. Of the 64 patients undergoing renal transplantation 13 (20.3%) developed leukopenia within 3 +/- 2 months after transplantation with severe neutropenia in 5 (7.8%). All patients were on MMF and VGC (VGC 605 +/- 296 mg/d). Leukopenia was significantly associated with simultaneous liver-kidney transplantation and with second kidney transplantations (P < .01). The incidence of leukopenia was higher among patients under VGC since day 1 of transplantation (P = .008) with maximal incidence observed among patients prescribed 900 mg/d as opposed to those on lower doses (P < .01). There was no increase in CMV infection among patients with a low dose of VGC. No patient developed clinical CMV disease. In conclusion, VGC prophylaxis was associated with an increased frequency of leukopenia on MMF-tacrolimus treated patients or regimens. Low-dose VGC for CMV prophylaxis appeared to be as effective as high-dose treatment, and associated less frequently with leukopenia and neutropenia.

Zero-Time Kidney Histology Predicts Early Graft Function

Our purposes are to determine the impact of histological factors observed in zero-time biopsies on early post transplant kidney allograft function. We specifically want to compare the semi-quantitative Banff Classification of zero time biopsies with quantification of % cortical area fibrosis. Sixty three zero-time deceased donor allograft biopsies were retrospectively semiquantitatively scored using Banff classification. By adding the individual chronic parameters a Banff Chronic Sum (BCS) Score was generated. Percentage of cortical area Picro Sirius Red (%PSR) staining was assessed and calculated with a computer program. A negative linear regression between %PSR/ GFR at 3 year post-transplantation was established (Y=62.08 +-4.6412X; p=0.022). A significant negative correlation between arteriolar hyalinosis (rho=-0.375; p=0.005), chronic interstitial (rho=0.296; p=0.02) , chronic tubular ( rho=0.276; p=0.04) , chronic vascular (rho= -0.360;P=0.007), BCS (rho=-0.413; p=0.002) and GFR at 3 years were found. However, no correlation was found between % PSR, Ci, Ct or BCS. In multivariate linear regression the negative predictive factors of 3 years GFR were: BCS in histological model; donor kidney age, recipient age and black race in clinical model. The BCS seems a good and easy to perform tool, available to every pathologist, with significant predictive short-term value. The %PSR predicts short term kidney function in univariate study and involves extra-routine and expensive-time work. We think that %PSR must be regarded as a research instrument.

C4d Presence in Kidney Allograft Biopsy: Sensitivity and Specifity of Immunoperoxidase vs Immunofluorescence

OBJECTIVES: Evaluate the sensitivity/specificity of immunoperoxidase method in comparison with the standard immunofluorescence. MATERIAL AND METHODS: Retrospective review of 87 biopsies made for allograft dysfunction. Immunofluorescence (IF) was performed in frozen allograft biopsies using monoclonal antibody anti-C4d from Quidel®. The indirect immunoperoxidase (IP) technique was performed in paraffin-embebbed tissue with polyclonal antiserum from Serotec®. Biopsies were independently evaluated by two nephropathologist according Banff 2007 classification. RESULTS: By IF, peritubular C4d deposition were detected in 60 biopsies and absent in 27 biopsies. The evaluation of biopsy by IP was less precise due to the presence of background and unspecific staining. We find 13.8% (12/87) of false negative and Banff classification concordance in 79.3% (69/87) of cases (table1). The ROC curve study reveal a specificity of 100% and sensitivity of 80.0 % of IP method in relation to the gold standard (area under curve:0.900; 95% Confidence interval :0.817-0.954; p=0.0001). Banff Classification C4d Cases Immunofluorescence Immunoperoxidase n =87 Diffuse Negative 3 (3.4%) Focal Negative 9 (10.3%) Negative Negative 27 (31.0%) Diffuse Diffuse 33 (37.9%) Focal Focal 9 (10.3%) Diffuse Focal 6 (6.9%) CONCLUSION: The IP method presents a good specificity, but lesser sensitivity to C4d detection in allograft dysfunction. The evaluation is more difficult, requiring more experience of the observer than IF method. If frozen tissue is unavailable, the use of IP for C4d detection is acceptable.

Epidemiology of Asthma and Allergic Diseases in Portuguese Speaking Regions

The application of the same epidemiological methods in different countries allows important comparisons between different races and cultures. During the last decade, two large multi-centres epidemiological studies, the Portuguese Study of Allergic Diseases in Childhood (PAC study) and the International Study of Asthma and Allergies in Childhood (ISAAC study), were implemented in Portuguese speaking regions. The main objectives were to assess and compare allergic diseases prevalence. The authors stress out the significant differences observed in schoolchildren from the three continents, with different genetic and environmental background. It was found an increase trend in the prevalence of all allergic diseases, mainly rhinitis, in last decade. Rhinitis has been identified as an independent risk factor for asthma in Caucasian population.

Mineral and Bone Disease (MBD) on a Kidney Transplant Patient

A 50-year-old post-menopausal recipient of a kidney allograft with bone pain, osteoporosis, persistent hypercalcaemia and elevated parathormone (PTH) levels, despite a satisfactory graft function, was treated with bisphosphonates and cinacalcet starting, respectively, 5 and 6 months after renal transplantation (RT). Sixteen months after treatment, there was improvement of bone mineral density (BMD) measured by dualenergy X-ray absorptiometry (DEXA). A bone biopsy was taken, unveiling a surprising and worrisome result. Post-RT bone disease is different from classic CKD-MBD and should be managed distinctly, including, in some difficult cases, an invasive evaluation through the performance of a bone biopsy, as suggested in the KDIGO guidelines.

Brain Natriuretic Peptide Levels Predict Morbidity and Mortality in Haemodialysis Patients

Background: Brain natriuretic peptide is a predictor of mortality in multiple cardiovascular diseases but its value in patients with chronic kidney disease is still a matter of debate. Patients and methods: We studied 48 haemodialysis patients with mean age 70.0±13.9 years,62.5% female, 43.8% diabetics, with a mean haemodialysis time of 38.1±29.3 months. To evaluate the role of brain natriuretic peptide as a prognostic factor in this population we performed a two-session evaluation of pre- and postmid-week haemodialysis plasma brain natriuretic peptide concentrations and correlated them with hospitalisation and overall and cardiovascular mortality over a two-year period. Results: There were no significant variations in pre– and post-haemodialysis plasma brain natriuretic peptide concentrations. Pre- and post-haemodialysis brain natriuretic peptide concentrations were significantly greater in patients who died from all causes(p=0.034 and p=0.001, respectively) and from cardiovascular causes (p=0.043 and p=0.001, respectively). Patients who were hospitalised in the two-year study period also presented greater pre- and posthaemodialysis brain natriuretic peptide concentrations(p=0.03 and p=0.036, respectively). Patients with mean brain natriuretic peptide concentrations ≥ 390 pg/mL showed a significantly lower survival at the end of the two-year study period. Conclusion: Brain natriuretic peptide was a good predictor of morbidity and mortality (overall and cardiovascular) in our population.

Thoracic Manifestations of Connective Tissue Diseases

Connective tissue diseases (CTDs) comprise several immunologic systemic disorders, each of which associated with a particular set of clinical manifestations and autoimmune profile. CTDs may cause numerous thoracic abnormalities, which vary in frequency and pattern according to the underlying disorder. The CTDs that most commonly involve the respiratory system are progressive systemic sclerosis, systemic lupus erythematosus, rheumatoid arthritis, Sjögren syndrome, polymyositis, dermatomyositis, and mixed connective tissue disease. Pulmonary abnormalities in this group of patients may result from CTD-related lung disease or treatment complications, namely drug toxicity and opportunistic infections. The most important thoracic manifestations of CTDs are interstitial lung disease and pulmonary arterial hypertension, with nonspecific interstitial pneumonia being the most common pattern of interstitial lung disease. High-resolution computed tomography is a valuable tool in the initial evaluation and follow-up of patients with CTDs. As such, general knowledge of the most common high-resolution computed tomographic features of CTD-related lung disease allows the radiologist to contribute to better patient management.

Anti-Phospholipase A2 Receptor Antibodies in the Diagnosis of Idiopathic Membranous Nephropathy

Circulating anti-phospholipase A2 receptor antibodies (anti-PLA2R) have been described in 70% to 80% of the patients with idiopathic membranous nephropathy (iMN), but not in patients with secondary membranous nephropathy or other glomerular diseases. The goal of this study was to evaluate the sensitivity and specificity of the assay for anti-PLA2R in the diagnosis of iMN. Anti-PLA2R IgG, Elisa and immunofluorescence tests were used to detect circulating anti-PLA2R. These tests were applied in 53 patients who had a kidney biopsy. Of these, 38 had histological diagnosis of membranous nephropathy (MN) and the remaining had other glomerular diseases. The MN was classified as idiopathic in 33 patients after clinical exclusion of secondary causes. Anti-PLA2R were positive in 57.6% of the patients with iMN. All patients with secondary membranous nephropathy or other glomerular diseases did not show circulating anti-PLA2R. The sensitivity was 57.6% (CI 39.2-74.5) and specificity 100% (CI 47.8-100), AUC 0.788; p < 0.0001 for the detection of iMN. 71.4% of the iMN patients that tested negative for anti-PLA2R were in partial or complete remission. The detection of anti-PLA2R in the studied population had a specificity of 100% for the iMN diagnosis. Prior treatments seem to make the test negative and contribute to a lower sensitivity.

Idiopathic Hypocomplementaemic Tubulointerstitial Nephritis

Background: Tubulointerstitial nephritis (TIN) is a common cause of kidney injury typically seen in association with drug exposure, infection or autoimmune diseases. However, TIN with interstitial immune complex deposition, without glomerular injury, is rarely observed. Case: We report a case of a 64-yearold Indian woman admitted for dialysis-requiring renal failure, without involvement of other organs. Urinalysis showed blood 3+ and 24h proteinuria of 1.5 g. Renal ultrasound revealed normal sized kidneys with loss of parenchymal-sinus differentiation. Laboratory tests disclosed low C3, positive ANA but negative anti-dsDNA, SSA and SSB. Serum protein electrophoresis was normal. The renal biopsy showed tubulointerstitial nephritis with positive immunoglobulin staining involving the interstitium and tubular basement membrane with glomerular sparing. The patient started prednisolone (1mg/kg/day) without recovery of the renal function. Conclusion: Idiopathic hypocomplementaemic tubulointerstitial nephritis is a rare disease with few cases described in the literature. To our knowledge this is the first case reported in Portugal.