Evaluation of the human immunodeficiency virus type 1 and 2 antibodies detection in dried whole blood spots (dbs) samples

Human Immunodeficiency Vírus Type 1 and 2 antibodies detection was performed in 457 dried whole blood spots samples (S&S 903). Q-Preven HIV 1+2 was the screening test used. The results were compared with the gold standard serum tests by ELISA (Cobas Core e Axsym HIV1/2 gO) and imunofluorescence was the definitive confirmatory test. The samples were obtained from the Hospital Nossa Senhora da Conceição in Porto Alegre, RS - Brazil, through whole blood transfer to filter paper card and sent to Caxias do Sul, RS - Brazil where the tests were performed. The dried whole blood spot stability was evaluated with two different panels. The first one was composed of five negative and five positive samples stored at room temperature, 4 ºC, -20 ºC and -70 ºC, while the second was composed of two negative and three positive samples stored at 37 ºC (humidity <50%). Each sample was screened every week for six weeks. These measurement results didn't show variation during the study period. The detected sensibility was 100%, specificity was 99.6%, the positive predictive value was 99.5% and negative predictive values were 100%. The results demonstrated high performance characteristics, opening a new perspective of dried whole blood spot utilization in HIV screening diagnosis.

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.

Renal Pathology in Portuguese HIV-Infected Patients

HIV-infected patients may be affected by a variety of renal disorders. Portugal has a high incidence of HIV2 infection and a low prevalence of HIV-infected patients under dialysis treatment. The aim of this study was to characterise the type of renal disease in Portuguese HIV-infected patients and to determine if HIV2 infection is associated to renal pathology. Only 60 of the 5158 HIV-infected patients followed in our hospital underwent renal biopsy. Clinical and laboratory data and the type of renal disease were reviewed. Male gender was predominant (76.7%), as was Caucasian race (78.3%). Mean age was 37.9±10.6 years. The majority had criteria for AIDS, 66% were on combined antiretroviral therapy and 18.3% were on dialysis. The predominant lesions were immunecomplex glomerulonephritis (n=19), tubulointerstitial nephropathy (n=12), focal segmental glomerulosclerosis(n=11), followed by HIVAN (n=8). Other patterns(amyloidosis, vasculitis, minimal change lesion) were observed. Only three patients were HIV2 infected, and presented diabetic nephropathy, acute tubular necrosis and tubulointerstitial nephritis. No correlations between clinical findings and renal pathology were found. In conclusion, renal disease in HIV patients has a broad spectrum, and renal biopsy remains the gold standard for establishing the diagnosis and guide treatment. Renal disease is not frequent in HIV2-infected patients, and, when present, is probably not directly associated with HIV infection.

Validation of a rapid stool antigen test for diagnosis of Helicobacter pylori infection

The aim of this study was to validate the rapid lateral flow Helicobacter pylori stool antigen test (One step H. pylori antigen test, ACON laboratories, San Diego, USA; Prime diagnostics, São Paulo), using 13C-Urea Breath Test as the gold standard for H. pylori infection diagnosis. A total of 98 consecutive patients, asymptomatic or dyspeptic, entered the study. Sixty-nine were women, with a mean age of 45.76 ± 14.59 years (14 to 79 years). In the H. pylori-positive group, the rapid stool antigen test detected H. pylori antigen in 44 of the 50 positive patients (sensitivity 88%; 95% CI: 75.7-95.5%), and six false-negative; and in the H. pylori-negative group 42 presented negative results (specificity 87.5%; 95% CI: 74.7-95.3%), and six false-positive, showing a substantial agreement (Kappa Index = 0.75; p < 0.0001; 95% CI: 0.6-0.9). Forty four of fifty patients that had positive stool antigen were H. pylori-positive, the PPV of the stool antigen test was 88% (95% CI: 75.7-95.5%), and 42 patients with negative stool antigen test were H. pylori-negative, the NPV of the stool antigen test was 87.5% (95% CI: 74.7-95.3%). We conclude that the lateral flow stool antigen test can be used as an alternative to breath test for H. pylori infection diagnosis especially in developing countries.

C4d Detection in Renal Allograft Biopsies: Immunohistochemistry vs. Immunofluorescence

Introduction. Peritubular capillary complement 4d staining is one of the criteria for the diagnosis of antibody-mediated rejection, and research into this is essential to kidney allograft evaluation. The immunofluorescence technique applied to frozen sections is the present gold-standard method for complement 4d staining and is used routinely in our laboratory. The immunohistochemistry technique applied to paraffin-embedded tissue may be used when no frozen tissue is available. Material and Methods. The aim of this study is to evaluate the sensitivity and specificity of immunohistochemistry compared with immunofluorescence. We describe the advantages and disadvantages of the immunohistochemistry vs. the immunofluorescence technique. For this purpose complement 4d staining was performed retrospectively by the two methods in indication biopsies (n=143) and graded using the Banff 07 classification. Results. There was total classification agreement between methods in 87.4% (125/143) of cases. However, immunohistochemistry staining caused more difficulties in interpretation, due to nonspecific staining in tubular cells and surrounding interstitium. All cases negative by immunofluorescence were also negative by immunohistochemistry. The biopsies were classified as positive in 44.7% (64/143) of cases performed by immunofluorescence vs. 36.4% (52/143) performed by immunohistochemistry. Fewer biopsies were classified as positive diffuse in the immunohistochemistry group(25.1% vs. 31.4%) and more as positive focal (13.2% vs. 11.1%). More cases were classified as negative by immunohistochemistry (63.6% vs. 55.2%). Study by ROC curve showed immunohistochemistry has a specificity of 100% and a sensitivity of 81.2% in relation to immunofluorescence (AUC: 0.906; 95% confidence interval: 0.846-0.949; p=0.0001). Conclusions. The immunohistochemistry method presents an excellent specificity but lower sensitivity to C4d detection in allograft dysfunction. The evaluation is more difficult, requiring a more experienced observer than the immunofluorescence method. Based on these results, we conclude that the immunohistochemistry technique can safely be used when immunofluorescence is not available.

Cistectomia Radical e o seu Impacto na Sexualidade Feminina: uma Revisão da Literatura

Objectivo: A cistectomia radical (CR) é considerada o “gold-standard” no tratamento curativo dos tumores vesicais músculo-invasivos localizados. Nas mulheres implica classicamente a remoção da bexiga e órgãos adjacentes: uretra, parede anterior da vagina,útero e anexos. Em relação à derivação urinária, as mais utilizadas são a neobexiga ortotópica e o conducto ileal. Tendo em conta o grande impacto físico e psicológico que esta cirurgia tem na vida das mulheres, nomeadamente a nível sexual, procedeu-se a uma revisão da literatura sobre o tema, com vista a caracterizar a disfunção sexual secundária a CR, bem como técnicas e tratamentos existentes para minimizar a sua incidência. Métodos: Realizou-se uma revisão bibliográfica da literatura publicada entre 2000 e 2008, com recurso à Medline®/PubMed®, sobre o impacto da cistectomia radical e diferentes derivações urinárias na vida sexual das mulheres tratadas. Resultados: A CR tem impacto negativo na sexualidade feminina. Tal é independente do tipo de derivação urinária utilizada, prendendo-se com factores como lesões nervosas e vasculares decorrentes da técnica cirúrgica empregue. Conclusões: A CR é uma cirurgia com grande impacto na sexualidade feminina. É possível, alterando a técnica cirúrgica, promover à diminuição da disfunção sexual feminina subsequente a CR.

Comparison of five methods for oxacillin susceptibility testing of Staphylococcus aureus isolates from cystic fibrosis patients

Methicillin-resistant Staphylococcus aureus (MRSA) are now a worldwide problem. Cystic fibrosis (CF) patients are commonly colonized and infected by MRSA. Accurate oxacillin susceptibility testing is mandatory for the adequate management of these patients. We performed a comparison of the accuracy of different tests in CF isolates, including methicillin-susceptible S. aureus and MRSA with different SCCmec types, and using the mecA gene as the gold-standard. The sensitivity and specificity of oxacillin disc, Etest, and oxacillin agar screening plate were 100%. Sensitivity of the cefoxitin disc was 85% and specificity was 100%. For clinically relevant isolates, laboratories may consider the use of a combination of two phenotypic methods.

QUANTITATIVE REAL-TIME PCR (Q-PCR) FOR SPUTUM SMEAR DIAGNOSIS OF PULMONARY TUBERCULOSIS AMONG PEOPLE WITH HIV/AIDS

Objective: To assess quantitative real-time polymerase chain reaction (q-PCR) for the sputum smear diagnosis of pulmonary tuberculosis (PTB) in patients living with HIV/AIDS with a clinical suspicion of PTB.Method: This is a prospective study to assess the accuracy of a diagnostic test, conducted on 140 sputum specimens from 140 patients living with HIV/AIDS with a clinical suspicion of PTB, attended at two referral hospitals for people living with HIV/AIDS in the city of Recife, Pernambuco, Brazil. A Löwenstein-Jensen medium culture and 7H9 broth were used as gold standard.Results: Of the 140 sputum samples, 47 (33.6%) were positive with the gold standard. q-PCR was positive in 42 (30%) of the 140 patients. Only one (0.71%) did not correspond to the culture. The sensitivity, specificity and accuracy of the q-PCR were 87.2%, 98.9% and 95% respectively. In 39 (93%) of the 42 q-PCR positive cases, the CT (threshold cycle) was equal to or less than 37.Conclusion: q-PCR performed on sputum smears from patients living with HIV/AIDS demonstrated satisfactory sensitivity, specificity and accuracy, and may therefore be recommended as a method for diagnosing PTB.

EVALUATION OF METHODS IN DETECTING VANCOMYCIN MIC AMONG MRSA ISOLATES AND THE CHANGES IN ACCURACY RELATED TO DIFFERENT MIC VALUES

INTRODUCTION: Methicillin-Resistant Staphylococcus aureus (MRSA) presenting reduced susceptibility to vancomycin has been associated to therapeutic failure. Some methods used by clinical laboratories may not be sufficiently accurate to detect this phenotype, compromising results and the outcome of the patient. OBJECTIVES: To evaluate the performance of methods in the detection of vancomycin MIC values among clinical isolates of MRSA. MATERIAL AND METHODS: The Vancomycin Minimal Inhibitory Concentration was determined for 75 MRSA isolates from inpatients of Mãe de Deus Hospital, Porto Alegre, Brazil. The broth microdilution (BM) was used as the gold-standard technique, as well as the following methods: E-test® strips (BioMérieux), M.I.C.E® strips (Oxoid), PROBAC® commercial panel and the automated system MicroScan® (Siemens). Besides, the agar screening test was carried out with 3 µg/mL of vancomycin. RESULTS: All isolates presented MIC ≤ 2 µg/mL for BM. E-test® had higher concordance (40%) in terms of global agreement with the gold standard, and there was not statistical difference among E-test® and broth microdilution results. PROBAC® panels presented MICs, in general, lower than the gold-standard panels (58.66% major errors), while M.I.C.E.® MICs were higher (67.99% minor errors). CONCLUSIONS: For the population of MRSA in question, E-test® presented the best performance, although with a heterogeneous accuracy, depending on MIC values.

Analgesia e Anestesia Obstétricas na Maternidade do Hospital D. Estefânia: Estudo Retrospectivo

Resumo: Por intermédio deste estudo, pretendeu-se verificar qual a realidade em termos de analgesia e anestesia obstétricas na Maternidade do Hospital D. Estefânia, ao longo de 4 anos. Para isso, foi realizado um estudo retrospectivo no período entre Janeiro de 2005 e Dezembro de 2008. Foram avaliados a classificação ASA das parturientes, o número total de partos, o número de parturientes submetidas a técnicas locorregionais e suas complicações, número de cesarianas e a necessidade de conversão de técnica regional para anestesia geral. No período do estudo, houve um total de 8291 partos, maioritariamente em mulheres ASA I, dos quais 2643 foram cesarianas. A maioria das parturientes (77%) foi submetida a uma técnica locorregional, para analgesia de trabalho de parto ou anestesia para cesariana, com baixa taxa de complicações (2,9%) e com rara necessidade de conversão para anestesia geral (3,5%). As autoras concluiram que, na Maternidade do Hospital D. Estefânia, a epidural continua a ser a técnica gold standard para analgesia do trabalho de parto, com raras complicações e permitindo a fácil conversão para anestesia para cesariana.

LIVER BIOPSY: IMPORTANCE OF SPECIMEN SIZE IN THE DIAGNOSIS AND STAGING OF CHRONIC VIRAL HEPATITIS

Liver biopsy is the gold standard method for the grading and staging of chronic viral hepatitis, but optimal biopsy specimen size remains controversial. The aim of this study was to evaluate the quality of liver specimen (number of portal tracts) and to evaluate the impact of the number of portal tracts in the staging of chronic hepatitis. Material and Methods: 468 liver biopsies from consecutive patients with hepatitis C virus and hepatitis B virus infection from 2009 to 2010 were evaluated. Results: The length of fragment was less than 10 mm in 43 cases (9.3%), between 10 and 14 mm in 114 (24.3%), and ≥ 15 mm in 311 (64.4%); of these, in 39 (8.3%) cases were ≥ 20 mm. The mean representation of portal tracts was 17.6 ± 2.1 (5-40); in specimens ≥ 15 mm the mean portal tract was 13.5 ± 4.7 and in cases ≤ 15 mm was 11.4 ± 5.0 (p = 0.002). Cases with less than 11 portal tracts were associated with F3, and cases with 11 or more portal tracts with F2 (p = 0.001). Conclusion: this study demonstrated the good quality of liver biopsy and a relationship between the macroscopic size of the fragment and the number of portal tracts.

MALARIA DIAGNOSIS BY LOOP-MEDIATED ISOTHERMAL AMPLIFICATION (LAMP) IN THAILAND

The loop-mediated isothermal amplification method (LAMP) is a recently developed molecular technique that amplifies nucleic acid under isothermal conditions. For malaria diagnosis, 150 blood samples from consecutive febrile malaria patients, and healthy subjects were screened in Thailand. Each sample was diagnosed by LAMP, microscopy and nested polymerase chain reaction (nPCR), using nPCR as the gold standard. Malaria LAMP was performed using Plasmodiumgenus and Plasmodium falciparum specific assays in parallel. For the genus Plasmodium, microscopy showed a sensitivity and specificity of 100%, while LAMP presented 99% of sensitivity and 93% of specificity. For P. falciparum, microscopy had a sensitivity of 95%, and LAMP of 90%, regarding the specificity; and microscopy presented 93% and LAMP 97% of specificity. The results of the genus-specific LAMP technique were highly consistent with those of nPCR and the sensitivity of P. falciparum detection was only marginally lower.

Porokeratosis Ptychotropica of the Scrotum: Dermoscopic Evaluation of an Atypical Presentation

Porokeratosis ptychotropica is a rare variant of porokeratosis that is classically located on the gluteal and perianal regions, seldom extending to the genitalia. The authors report an atypical presentation of porokeratosis ptychotropica and discuss the use of dermoscopy in evaluating this dermatosis. Dermoscopic findings, although not specific to this variant of porokeratosis, are helpful in the differential diagnosis of other genital disorders. Histopathology, through the visualization of multiple cornoid lamellae, prevails as the gold standard for the definite diagnosis of porokeratosis ptychotropica.

Estudo Comparativo entre Dois Tipos de Eco-Contrastes: Echovist® e Levovist®, Avaliação da Permeabilidade Tubária em Infertilidade Feminina

Na propedêutica inicial do casal infértil, a realização da Sonossalpingografia (SoSG) contrastada através de dois tipos de ecocontrastes, Echovist® e Levovist®, durante a realização da ultra-sonografia ginecológica convencional pode, em casos seleccionados, substituir como exame de “screening” da permeabilidade tubária a Histerossalpingografia (HSG) e a Laparoscopia com cromotubação (LPC). Objectivos: Comparar os resultados da permeabilidade tubária através da SoSG contrastada com Echovist® ou com Levovist® e a HSG e determinar a sua acuidade em relação a LPC considerada “gold-standard”. Pacientes e métodos: Foram avaliadas prospectivamente 90 pacientes inférteis submetidas a SoSG em que se utilizou o contraste ecogénico Echovist® e 28 pacientes em que se utilizou o eco-realçador Levovist®. Para a HSG utilizou-se, em todas as pacientes, contraste iodado e hidrossolúvel Telebrix®. A observação da permeabilidade tubária teve sua avaliação final e sistemática pela LPC. Resultados: No estudo das trompas pelo Echovist® observamos permeabilidade em 67 pacientes (74,4%) e obstruções bilaterais em 23 das pacientes (25,6%) e pelo Levovist®, respectivamente, 22 (78,6%) e 6 pacientes (21,4%). Na comparação da avaliação da permeabilidade tubária entre a SoSG com Echovist® e LPC encontramos: especificidade € 91,3%, sensibilidade (S) 100%, falsos positivos (FP) 8,7%, falsos negativos (FN) 0%, valor preditivo positivo (VPP) 97,1%, valor preditivo negativo (VPN) 100% e Kappa de 96,5%, e entre a HSG e LPC, neste grupo Echovist® foram: E 100%, S 91,04%, FP 0%, FN 8,96%, VPP 100%, VPN 79,31% e Kappa de 88,6%. Na comparação da avaliação da permeabilidade tubária entre a SoSG com Levovist® e LPC encontramos: E 100%, S 100%, FP 0%, FN 0%, VPP 100%, VPN 100% e Kappa de 100%, e entre a HSG e LPC, no grupo Levovist® foram: E 100%, S 86,36%, FP 0%, FN 13,64%, VPP 100%, VPN 66,67% e Kappa de 82,2%. Conclusões: As Sonossalpingografias (SoSG) contrastadas utilizando-se como eco-realçadores o Echovist® ou o Levovist® podem ser consideradas exames complementares equivalentes na rotina da avaliação inicial do factor tubário por apresentarem, além do mesmo composto químico activo, alta sensibilidade, especificidade e concordância, ambos com acuidade superior à HSG quando comparados com a LPC.

Importância da Prova de Synacthen no Diagnóstico Diferencial de Pubarca Precoce

Introdução: Nos doentes com pubarca precoce, o gold-standard para o diagnóstico diferencial entre pubarca precoce idiopática (PPI) e a forma não clássica da hiperplasia congénita da suprarrenal (HCSR--NC) é a prova de Synacthen. Esta permite também estimar a reserva adrenal de cortisol nos doentes com HCSR-NC.Objetivos: Comparar as características clínicas e perfil hormonal basal dos doentes com pubarca pre-coce; avaliar a importância da prova de Synacthen no diagnóstico diferencial entre PPI e HCSR-NC e na determinação da reserva adrenal de cortisol. Material e métodos: Estudo transversal de doentes com pubarca precoce que realizaram prova de Synacthen. Resultados: Foram incluídos 43 doentes, com idade mediana de 7,5 anos (3,5-9,4), sendo 37 (86,0%) do sexo feminino. Na prova de Synacthen, 37 (86,0%) foram classificados como PPI e 6 (14,0%) como HCSR-NC.Não houve diferencças significativas entre os 2 grupos quanto às características clínicas e doseamentos basais de ACTH, cortisol e androgénios da suprarrenal. A 17-OHP basal e estimulada foi mais elevada nos doentes com HCSR-NC (p = 0,001 e p < 0,001, respetivamente) (basal: 4,62 ± 3,70 ng/ml [0,80-10,50];estimulada: 35,41 ± 24,87 ng/ml [12,0-80,2]) do que nos doentes com PPI (basal: 1,04 ± 0,77 ng/ml [0,22-3,80]; estimulada: 4,18 ± 1,71 ng/ml [1,0-8,96]). O cut-off basal habitualmente proposto (< 2,0 ng/ml) paraa distinção entre estes grupos não o permitiu em 2 doentes, que apenas foram diagnosticados após realização da prova de Synacthen. Dois doentes com HCSR-NC (33,3%) tiveram cortisol após estimulação< 18 g/dl, revelando necessidade de tratamento com glucocorticoide em stress. Os doentes com HCSR--NC com valores mais elevados de 17-OHP basal tiveram valores de cortisol mais baixos após estimulação(p = 0,004; r = -0,43).Conclusão: A realização desta prova foi útil para distinguir os doentes com HCSR-NC e PPI, pois nenhum valor de 17-OHP basal permitia fazer o diagnóstico diferencial definitivo. Em alguns doentes com HCSR-NCa prova revelou secreção inapropriada de cortisol em stress, contribuindo para a decisão terapêutica.