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#2
04.06.2017, 20:28
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DIAGNOSIS — The laboratory findings should be interpreted together with clinical manifestations, exposure history, occupation, and history of past infection [ 36,37 ]. Laboratory tools for diagnosis of brucellosis include culture, serology, and polymerase chain reaction (PCR) [ 38 ]. Ideally, the diagnosis is made by culture of the organism from blood or other sites such as bone marrow or liver biopsy specimens. The sensitivity of culture is limited; if standard blood cultures are negative and brucellosis remains a consideration, the lab should be alerted regarding suspicion for brucellosis so that additional blood culture techniques can be performed. Serologic testing should also be performed; serum agglutination and ELISA are the most common serologic tests.
Results of routine laboratory studies are usually nonspecific. White blood cell counts are usually normal to low; pancytopenia can occur. Minor abnormalities in hepatic enzymes are relatively common [ 39,40 ]. In neurobrucellosis, abnormalities of the cerebrospinal fluid typically include a pleocytosis of 10 to 200 white blood cells (predominantly mononuclear cells), elevated protein levels, and hypoglycorrhachia [ 41 ]. In the setting of findings consistent with aseptic meningitis, elevated levels of adenosine deaminase in cerebrospinal fluid suggest brucella meningitis (or tuberculous meningitis) [ 42 ]. Radiographs, bone scans, computerized tomography, magnetic resonance imaging, and echocardiography may be helpful in evaluating focal disease but do not provide a definitive diagnosis. Culture — The diagnosis of brucellosis is established when Brucella are isolated from blood, bone marrow, or other body fluids or tissues [ 15 ]. Culture techniques are time consuming, insensitive and pose risk for laboratory infection [ 3 ]. The classic biphasic (solid and liquid) Ruiz-Castaneda blood culture technique is still used in developing settings but automated blood culture systems are more effective [ 10 ]. The percentage of cases with positive blood cultures ranges from 15 to 70 [ 10 ]. The majority of blood cultures are positive between the 7th and 21st day [ 43 ]. The semiautomatic methods (BACTEC 9204 and Bac/Alert) shorten considerably the time taken for detection; the presence of Brucella can be detected by the third day of incubation [ 7,15,44 ]. Lysis-centrifugation technique provides rapid diagnosis and also has high sensitivity in confirmation of brucellosis, especially of chronic illness. In one report, the lysis-centrifugation technique was more sensitive than Ruiz-Castaneda culture in both acute (91 versus 72 percent) and chronic brucellosis (74 versus 33 percent) [ 45 ]. Compared with early versions of automated blood culture systems, the lysis-centrifugation approach had shorter time to detection, but in some cases, the automated systems produced higher sensitivity rates [ 46 ]. Studies with the newer continuous monitoring systems indicate that the BACTEC 9000 series is able to achieve times to detection that are shorter than those of lysis-centrifugation and has greater sensitivity [ 47 ]. Bone marrow culture is considered the gold standard for the diagnosis of brucellosis. It is significantly more sensitive than blood culture, especially in chronic cases. The time to detection is shorter, and prior use of antibiotics does not reduce the sensitivity [ 48 ]. However, because harvesting bone marrow for culture is an invasive procedure, bone marrow culture is reserved for patients with abnormal hematologic findings, fever of unknown origin, and negative brucellosis serology [ 10,11 ]. Serologic tests — A presumptive diagnosis of brucellosis can be made by demonstrating elevated or rising titers of specific serum antibodies [ 15 ]. The interpretation of serological tests can be difficult, particularly in the setting of chronic infection, reinfection, relapse, and in endemic areas where a high proportion of the population has antibodies against brucellosis [ 27 ]. Positive serological tests results can persist long after recovery in treated individuals, so it is not always possible to distinguish serologically between active and past infection [ 36,37,49 ]. A variety of serologic methods that allow the detection of antibodies against the cell wall components or some cytoplasmic proteins have been used:
ELISA is the second most common serologic method utilized in evaluating patients with suspected Brucella infections. ELISA is rapid, objective, highly sensitive and specific; it measures IgM, IgG, and IgA [ 44 ]. While ELISA with S-LPS is a very promising test, there are problems of inter-laboratory comparability due to issues related to standardization, reagent quality and interpretation of results (particularly when based on optical density readings alone); standard reference materials are needed [ 7,15,36 ]. One investigation concluded that ELISA did not improve diagnostic accuracy compared to SAT and Coombs in combination [ 53 ]. Another showed that the sensitivity of either ELISA IgM or IgG were lower than SAT; the sensitivity and specificity were similar when IgM and IgG were used in combination [ 54 ]. Diagnostic use of ELISA anti-LPS and anti-cytoplasmic protein antibodies appears to be helpful in combination [ 55 ]. Rose Bengal plate agglutination test is often used as a rapid screening test, with very high sensitivity (>99 percent), and fairly high specificity [ 53 ]. The Coombs and immunocapture agglutination (Brucellacapt) tests may be more suitable in relapsing brucellosis and patients with persistent active infection [ 36,37 ]. The 2-mercaptoethanol (2-ME) agglutination test measures IgG antibodies only, and is a good marker to follow disease activity after initiation of therapy [ 15,27 ]. There are a number of disadvantages associated with serologic tests. Cross-reactivity with other bacteria is a problem with standard tube agglutination; cross reacting organisms include Francisella tularensis, Yersinia enterocolitica O:9, Escherichia coli O116 and O157, Salmonella urbana, Vibrio cholerae, Xanthomonas maltophilia, and Afipia clevelandensis [ 10,56 ]. False negative results are common early in the course of infection [ 57 ], in the setting of immunosuppression and in the presence of incomplete or blocking antibodies (serum agglutination) [ 58,59 ]. In addition, a ‘prozone’ phenomenon may also be observed with serum agglutination testing (eg, inhibition of agglutination at low dilutions due to an excess of antibodies or to non-specific serum factors) [ 15,56 ]. Molecular tests — Polymerase chain reaction (PCR) is a promising tool for rapid and accurate diagnosis of human brucellosis. PCR can be performed on blood or any body tissue and can yield positive results as early as 10 days after inoculation [ 10 ]. PCR-based laboratory tests cannot yet be considered a routine diagnostic method, however, given the need for standardization of methods, infrastructure, equipment, expertise and a better understanding of the clinical significance of the results [ 3,60 ]. A number of molecular tests are available for the identification of Brucella to the genus and species levels; these are research tools. PCR assays targeting omp43, omp31, the 16S rRNA gene, 16S to 23S internal transcribed spacer regions, heat shock protein genes and the perosamine synthetase gene have been developed to detect Brucella species [ 61 ]. All Brucella 16S rRNA gene sequences have been determined to be identical. Thus 16S, rRNA gene sequencing is useful for genus identification but cannot be used for species identification [ 62 ]. Resolution to species level is possible through ribotyping, amplified fragment length polymorphism analysis, DNA sequencing of omp2 and omp25, and PCR assays targeting species-specific insertions of IS711 or IS650 elements [ 61 ]. Synovial fluid — In general, analysis of synovial fluid (including cell count, glucose, protein, and culture) is not particularly helpful in the diagnosis of brucellosis [ 63 ]. In some circumstances, synovial fluid analysis may help distinguish Brucella arthritis from other causes. In the setting of Brucella arthritis, the synovial fluid white blood cell count does not generally exceed 15,000 cells/microL, which is similar to findings with reactive arthritis due to Salmonella and Yersinia species, but unlike the higher leukocyte count observed in other septic arthritides [ 64-66 ]. In brucellosis, lymphocytes frequently predominate (in contrast to septic arthritis due to other bacteria, in which polymorphonuclear leukocytes frequently predominate) [ 67 ]. 
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#3
05.06.2017, 08:20
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Уточнение
Ознакомился с данной статьей. Смотрел ранее сведения, например по Казахстану, -там при любых болях в суставах, в тч артроз -делают анализы на бруцелез, поэтому и был такой вопрос.
Вопрос, может ли быть бруцелез, если температуры на протяжении длительного периода (более 4-х мес.) не было, анализ по Хендельсону -отрицательный, ОАК и мочи сдавали несколько раз , С - белок, ревм.фактор- в норме, анализы на иерсенелии, опестархоз и др.-норм. Беспокоят быстрое начало и прогрессирование заболевания -остеартроз (по МРТ и ренгену дианостарован, хондромеляция (проявляется -неустойчивость -возникшая в течении 14 дней от первых болях в коленях), неврологи консультировали -в норме, ревмотологичкские исследования -в норме. Проведенным МРТ и ренген исследования в течении полугода -трижды - изменения в суставах. Мужчина, 40 лет, без вредных привычек, 82-76 кг. Что может вызывать остеартроз и как замедлить прогресирование - изменения вашего направления деятельности такое было?
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Линейный вид
