Gangrena de Fournier. Reporte de caso / Fournier's Gangrene. A Case Report

Resumen La gangrena de Fournier es una fascitis necrotizante tipo II que produce trombosis de los pequeños vasos subcutáneos, lo que genera que se propague a través de la piel del periné, área perianal y región genital. La mayoría de los casos tienen un foco perianal o colorectal en la mayoría de los casos y en una menor proporción se origina del tracto urogenital. La tasa de mortalidad varía entre el 7.8 y 50%1-3, únicamente el diagnóstico oportuno disminuye la morbilidad y mortalidad de este padecimiento. El tratamiento incluye desbridamiento quirúrgico de todo el tejido necrótico y el uso de antibióticos de amplio espectro.

Abstract Fournier's Gangrene is a type II necrotizing fascitis that leads to thrombosis of small subcutaneous vessels and spreads through the perianal and genital regions and the skin of the perineal. Most cases have a perianal or colorectal focus and in a smaller proportion it originates from the urogenital tract. The mortality rate varies between 7.8 and 50%1-3, only timely diagnosis decreases the morbidity and mortality of this condition. Treatment includes surgical debridement of all necrotic tissue and the use of broad-spectrum antibiotics.

Predictive value of troponin T levels for ischemic heart disease and mortality in patients on hemodialysis.

BACKGROUND: Serum cardiac troponin T (cTnT) levels are elevated in a high percentage of hemodialysis (HD) patients and as a result, they have been considered low specificity for ischemic heart disease (IHD). Recently, several authors have indicated the value of cTnT as a marker of IHD and left ventricular hypertrophy (LVH), as well as a mortality predictor. We try to establish the value of cTnT as an IHD marker and a mortality predictor in our patients on HD. SUBJECTS AND METHODS: Fifty-eight HD patients were prospectively studied from October 2000 to April 2002. Clinical and laboratory evaluations, including cTnT, C-reactive protein (CRP) and N terminal fragment of brain natriuretic peptide (pro-BNP) levels, were performed at the beginning of the study and at 6 and 18 months. HD patients with two or more cTnT measurements were classified in four groups: group I with all levels <0.04 ng/mL; group II with all levels between 0.04 and 0.1 ng/mL; group III with all levels >/=0.1 ng/mL; and group IV including those patients in whom cTnT levels increased during follow-up, switching from one group to another (from <0.04 to 0.04-0.1 or from 0.4-0.1 to >0.1 ng/mL). RESULTS: Mean and median cTnT levels were 0.07 +/- 0.09 and 0.04 ng/mL, respectively. Of clinically stable dialysis patients 15.5% had cTnT levels >0.1 ng/mL. In the stepwise multiple regression analysis, the subset of variables best explaining cTnT levels were pro-BNP levels, history of IHD and residual diuresis volume (r2=0.45). The analysis of variance (ANOVA linear regression analysis for repeated measures) showed an increase in cTnT and pro-BNP levels (significantly from 18 months). cTnT and CPR levels were the only variables predicting mortality (Cox's proportional hazards model). When patients were analyzed according to cTnT groups during the follow-up, no patient in group I (n=23) and only one patient in group II (n=11) experienced IHD; three patients in group III (n=12) had been diagnosed with IHD at the start of the study, and five patients in group IV (n=16) developed de novo IHD. CONCLUSIONS: Of patients on HD 15.5% had cTnT levels >0.1 ng/mL. The main variables associated with cTnT levels were IHD, pro-BNP levels and residual diuresis. cTnT and pro-BNP levels tended to increase with time on dialysis. cTnT together with CRP levels were the best mortality predictors in our HD patients. The stability over time of cTnT levels within normal ranges (<0.1 ng/mL) suggests a very low risk of subsequent IHD development, while a progressive and sustained increase in cTnT levels suggests a high risk of IHD development.

Clinical evaluation of cobas core anti-dsDNA EIA quant.

The measurement of antibodies to double-stranded DNA (anti-dsDNA) is a useful tool for the diagnosis and monitoring of patients with connective tissue diseases, particularly systemic lupus erythematosus (SLE). The aim of the present study was to compare a new enzyme-linked immunosorbent assay (ELISA) for the measurement of anti-dsDNA antibodies, which uses purified double-stranded plasmid DNA as the antigen (anti-dsDNA EIA Quant; Roche Diagnostics, Mannheim, Germany), with an established ELISA. The clinical usefulness of this new ELISA was also assessed. We measured anti-dsDNA antibodies in 398 serum samples that were divided into four groups: 1). routine samples sent to our laboratory for an antinuclear antibody (ANA) test (n=229), 2). samples from blood donors (n=74), 3). samples from patients with SLE (n=48), and 4) samples from patients with other autoimmune diseases (n=47). The methods used were the Cobas Core Anti-dsDNA EIA Quant (Roche Diagnostics, Mannheim, Germany) and the Anti-dsDNA test (Gull Diagnostics, Bois d'Arcy, France). We obtained a kappa index and Spearman correlation coefficient in the comparative study, and sensitivity, specificity, predictive values, and likelihood ratios in the clinical study. The results obtained show a good agreement between the two methods in both the qualitative results (kappa=0.91) and the quantitative data (r=0.854). The best accuracy, predictive values, likelihood ratios, and correlation with active disease were obtained with the Roche anti-dsDNA assay.

Clinical evaluation of a new automated anti-dsDNA fluorescent immunoassay.

The measurement of anti-double-stranded DNA (anti-dsDNA) antibodies is a useful tool for the diagnosis and the follow-up of systemic lupus erythematosus (SLE). Anti-dsDNA antibodies are involved in the pathogenesis of lupus nephritis and they are, specially the high-avidity antibodies, the most specific antibodies associated with SLE nephritis and active SLE. The aim of the present study was to assess the clinical utility of an enzyme-linked immunosorbent assay (EUSA) that utilizes a circular double-stranded plasmid DNA as a nucleic acid source, adapted to an automated fluorescence immunoassay (EliA dsDNA, Pharmacia, Freiburg, Germany). Also, we compared this method with other immunoassays used in clinical laboratories. We have measured anti-dsDNA antibodies in the serum of 179 patients with a positive result for antinuclear antibodies (ANA). Seventy six sera were from SLE patients (14 men and 62 women), and the other 103 sera (from 20 men and 83 women) constituted the control group. This latter group includes nine Sjogren's syndrome patients, six patients with rheumatoid arthritis and 88 with various other diseases, including connective tissue diseases (n=34), hepatopathies (n= 17; 11 primary biliary cirrhosis and 6 autoimmune hepatitis), and 37 patients with nonautoimmune diseases (viral hepatitis, renal disease, diabetes, exanthema and hypertension). Methods used were "EliA dsDNA" (Pharmacia, Germany), "Varelisa dsDNA" (Pharmacia, Germany), Farr (Amersham, UK) and Chritidia luciliae immunofluorescence test (Vitro-Immun, Germany). We assessed sensitivity, specificity, positive predictive value and negative predictive value in the clinical study, and kappa index and scatter plots in the comparative study. The results show a low concordance between methods (kappa < 0.6). The evaluated EliA method shows a very good specificity for SLE (93.2%) and a good sensitivity for active SLE (70.8%).

Antinuclear antibodies (ANA) screening by enzyme immunoassay with nuclear HEp-2 cell extract and recombinant antigens: analytical and clinical evaluation.

OBJECTIVES: Immunofluorescence assay (IFA) has been the standard method for antinuclear antibodies (ANA). To simplify and standardize the ANA test, generic ANA solid phase enzyme immunoassay has been promoted. The objective of the present work has been to study the relationship with IFA and the clinical usefulness of a generic EIA for ANA (COBAS Core HEp-2 ANA EIA, Roche Diagnostics). DESIGNS AND METHODS: We studied 74 healthy individuals, 119 patients with defined systemic autoimmune diseases, 26 patients with other autoimmune diseases, and 490 routine samples sent to laboratory for ANA analysis. RESULTS: Precision study showed intra-assay coefficient of variations (CVs) below 8% and inter-assay CVs below 10%. In relation to IFA, a 0.6 kappa index of agreement was obtained. COBAS-ANA concentrations increased according to IFA titer and greatest COBAS-ANA responses were obtained with pure or mixed homogeneous patterns and centromeric patterns. Analysis of COBAS-ANA response to particular antigenic specificities showed that SS-B, Scl-70 and U1sn-RNP specificities were saturating at high concentrations, whereas Jo-1, SS-A and nuclear and centromeric specificities exhibited lower responses. Elevated serum concentrations of IgG and IgM did not interfere COBAS-ANA, but high serum rheumatoid factor (RF) concentrations produced a decrease of ANA. For systemic lupus erythematosus (SLE) patients, the COBAS-ANA best efficiency was obtained with a cut-off of 0.9, with a sensitivity of 97% and a specificity of 88%, whereas the best IFA-ANA efficiency was obtained with a 1:80 dilution, giving a sensitivity of 90% and a specificity of 99%. There were no differences between areas under ROC curves for COBAS-ANA and IFA-ANA. For other systemic and nonsystemic autoimmune diseases sensitivity and specificity of COBAS-ANA were similar or higher than that of 1:160 IFA-ANA titer. CONCLUSION: Sensitivity and specificity of COBAS Core ANA-EIA for SLE and other systemic and nonsystemic autoimmune diseases, together with performance characteristics make it an adequate automated system for ANA screening.