Analysis of different staining techniques for c4d detection in renal allograft biopsies.

Capillary C4d deposition has been recognized as a marker of antibody-mediated rejection (AMR). Although the detection of capillary C4d by means of immunofluorescence (IF) in cryostat sections is well established, frozen tissue is not always available, thus limiting the diagnosis of AMR. The aim of the present study was to analyze different techniques for C4d staining and the prevalence of C4d in renal allograft biopsies. Detection of C4d was carried out using IF or immunohistochemistry (IHC) on frozen and paraffin sections of renal allograft biopsies available from the same patients. Biopsies obtained from 20 patients were classified into 3 groups: no rejection, acute rejection, and chronic allograft nephropathy (CAN). The capillary C4d deposition prevalence in frozen-IF, considered the gold standard technique for C4d detection, was 45% (9/20 cases). Compared with frozen-IF, the frozen-IHC technique presented an 85% concordance rate (17/20 cases; r = .70; P < .001; sensitivity = 77.8%; specificity = 90.9%). The paraffin-IF technique showed similar results, with an 80% concordance rate (16/20 cases; r = .64; P < .005; sensitivity = 55.6%; specificity = 100%), whereas C4d detection occurred in only 65% of paraffin-IHC cases (13/20; r = .30; not significant; sensitivity = 66.7%; specificity = 63.6%). No capillary C4d deposition was detected in cases without evidence of rejection. However, 4/7 cases (57%) of acute rejection were C4d positive. In the CAN group, 5/11 cases (45%) were C4d positive. In conclusion, these results demonstrated that frozen-IHC and paraffin-IF can be considered alternative techniques to frozen-IF for C4d detection. The paraffin-IHC technique displayed the lowest concordance rate for C4d detection.

[Testicular toxoplasmosis: a rare case of a testicular mass]. / Toxoplasmosis testicular: un caso raro de masa testicular.

Toxoplasma gondii is an intracellular protozoan infecting birds and mammals. Acute infection is asymptomatic in immune competent people. For immune deficient patients (acquired immune deficiency syndrome, lymphoma patients or those under steroids to prevent organ transplantation rejection) infection may be lethal. We describe an uncommon case of testicular toxoplasmosis in patient under steroids after organ transplantation with no positive serum test for HIV and/or systemic toxoplasmosis.

Toxoplasmosis testicular: un caso raro de masa testicular / Testicular toxoplasmosis: a rare case of mass testicular

El Toxoplasma gondii es un protozoario intracelular que infecta aves y mamíferos. La infección aguda es asintomática en pacientes inmunocompetentes. En pacientes con deficiencia inmunológica (síndrome de la inmunodeficiencia adquirida, linfomas o pacientes sometidos a terapia con corticoides para prevención derechazo de transplante de órganos) la infección puede ser fatal. Nosotros describimos un caso poco común de toxoplasmosis testicular en paciente sometido a transplante renal hace 6 años con serología negativa para el virus VIH y sin toxoplasmosis sistémica (AU)

Toxoplasma gondii is an intracellular protozoan infecting birds and mammals. Acute infection is asymptomatic in immune competent people. For immune deficient patients (acquired immune deficiency syndrome, lymphoma patients or those under steroids to prevent organ transplantation rejection) infection may be lethal. We describe an uncommon case of testicular toxoplasmosis in patient under steroids after organ transplantation with no positive serum test for HIV and/or systemic toxoplasmosis (AU)

Association between polymorphisms of the renin-angiotensin system and more severe histological forms of lupus nephritis.

AIMS: The pathogenesis of lupus nephritis (LN) has not been fully understood. The renin-angiotensin system (RAS) is implicated in various immunological and non-immunological phenomena, and the polymorphism of the RAS genes has been associated with cardiovascular and renal disease onset and outcome. Therefore, we evaluated the possible association between the polymorphism of the renin-angiotensin system genes and the development of the different types of histological lesions of lupus nephritis in Brazilian patients. METHODS: 72 LN patients and 65 healthy subjects (sex-and ethnic-matched) were enrolled and compared in this study. Following the extraction of genomic DNA from the leukocytes of the peripheral blood, the genotypes of the angiotensin converting enzyme (ACE I/D), of the angiotensinogen (AGT M235T) and of the angiotensin II type 1 receptor (AGTR1 A1166C) were determined by the polymerase chain reaction. The renal lesions of the patients with LN were classified by the histological findings according to the WHO criteria. In addition, the activity and chronicity indices were used to assess the severity of renal involvement. RESULTS: Among the 72 patients with LN, there were 17 class II, 8 class III, 40 class IV and 7 class V, according to the WHO criteria. Individuals with the III and IV classes of LN (WHO) showed a significantly increased DD genotype frequency of ACE I/D genes when compared to the control group (48% vs. 27.7%, chi2 = 4.885, df = 1, p = 0.0442). No difference was found in the distribution of the AGT M235T and AGTR1 A1166C genotype frequencies among the LN of the different histological classes (WHO) and healthy controls. There was no association between genetic polymorphism of ACE, AGT M235T and AGTR1 A1166C and susceptibility to lupus nephritis, nor histological activity and chronicity indices in renal biopsy among the patients studied. CONCLUSIONS: This study suggests that the DD genotype of the ACE may be associated with the development of the more severe histological forms of lupus nephritis.

[Recurrent hematuria in children: study of 250 cases]. / Hematúria recorrente na infância: estudo de 250 casos.

In order to analyse the etiology of recurrent hematuria in childhood, we studied 250 children, referred to our Service (age: 6 mo-17 ys; 102 female and 148 male). They were submitted to the following protocol: urine analyses, uroculture, serum total and fraction complement, electrophoresis of hemoglobin, serum creatinine, BUN, 24h urinary calcium, uric acid and protein, oral calcium load test in children with hypercalciuria (UCa greater than 4mg/kg/day). Radiological evaluation and renal percutaneous biopsy was performed when necessary. The following diagnostic distribution was obtained: Alport syndrome, 19; Berger disease, 15; other glomerulopathies, 45; hypercalciuria, 67; uric acid hyperexcretion, 10; nephrolithiasis, 27; urinary tract infection, 14; renal malformation, 8; no diagnosis, 43. Based in these results, we conclude that appropriate investigation on recurrent hematuria, leads to determination of etiology in over 80% of cases.

Cistinose na infancia. Apresentacao de tres casos. / Cystinosis in childhood. Report of 3 cases

A cistinose, alteracao metabolica rara (f=1/40.000), e a principal causa de sindrome de De Toni-Debre-Fanconi na infancia. Os autores apresentam o estudo de tres criancas, todas brancas, do sexo feminino, portadoras de cistinose nefropatica que se manifestou clinicamente como sindrome de Fanconi. O material para estudo histologico foi obtido por necropsia, no primeiro caso; por biopsia renal, no segundo; e puncao de medula ossea, na terceira crianca. Em todos os tecidos houve deposicao de cristais de cistina, em grande quantidade

Emprego da metilprednisolona em glomerulopatias na infancia. Estudo de vinte e seis casos. / Methylprednisolone in the treatment of glomerulopathies in childhood. Report of twenty-six cases

Os autores tentam avaliar as vantagens da metilprednisolona no tratamento das glomerulopatias. Os efeitos do medicamento foram estudados em 26 criancas com glomerulopatias, diagnosticadas por biopsia renal, estando todas descompensadas na ocasiao. A observacao destes primeiros casos deixou a impressao de que alguns pacientes realmente mostraram melhoras com o uso da droga