Fibrin degradation product D-dimer in the diagnosis of pulmonary embolism

Summary The study objective was to determine the specificity and sensitivity of plasma concentrations of D-dimer, a fibrin degradation product, as a marker for ongoing thrombotic and thrombolytic events in pulmonary embolism. A prospective study was performed in 74 patients with suspected pulmonary embolism who appeared in the emergency room with dyspnea and/or chest pain.The presence of pulmonary embolism was established by positive findings either in pulmonary angiography or lung scan. D-dimer concentrations were determined in all patients. In 11 patients with positive pulmonary angiography, D-dimer concentrations were monitored for 6–12 days.D-dimer concentrations were determined by a quantitative enzyme-linked immunoassay. Plasma probes of 26 patients (16 with/10 without positive pulmonary angiography) were reassayed with a semiquantitative latex agglutination assay. D-dimer levels were significantly higher in patients with pulmonary embolism (>1000 ng/mL in 41 out of 43) than in those without (<1000 ng/mL in all 21 patients) (p<0.01).The sensitivity and specificity for the ELISA were found to be 95% and 100%, respectively, for establishing the diagnosis of pulmonary embolism. In the latex assay the values were 81% and 60%, respectively.It is concluded that in patients with dyspnea and/or chest pain, determination of D-dimer in plasma by ELISA adds a valuable tool to the noninvasive diagnostic procedure for pulmonary embolism. From the time-course of D-dimer values we conclude that this assay might be valuable up to at least 6 days after symptom onset. The assay, however, is unreliable in malignancies or after surgery.Abbreviations apPE angiographically proven pulmonary embolism - hpPE highly probable pulmonary embolism - imPE highly improbable pulmonary embolism - rPE pulmonary embolism ruled out - pPE possible pulmonary embolism     

Value of D-dimer measurement in the exclusion diagnosis of pulmonary embolism]

Diagnosis of pulmonary embolism, a common and potentially fatal disease, is first based on clinical probability assessment, and often requires invasive testing such as pulmonary angiography. However, it often represents a diagnosis challenge. The measurement of D-dimer, a specific fibrin degradation product, was recently introduced in the diagnosis strategy. Even if D-dimer levels are highly sensitive in the diagnosis of pulmonary embolism, they are not specific of an on-going venous thromboembolic process. Its high negative predictive value enables to validly exclude diagnosis of pulmonary embolism, particularly in outpatients, in the case of D-dimer levels below a well-defined cut-off value. Prospective management studies confirmed that D-dimer measurement could be validly used as an initial screening test in patients with clinically suspected pulmonary embolism. Using such a diagnosis strategy, imaging tests would be performed only in the case of high D-dimer levels i.e. above the cut-off level. Even if they constitute the gold standard, conventional Elisa are not useful as a routine emergency test. New rapid and automated assays based on various principles (Elisa-derived or micro-latex agglutination) are now available. All demonstrated both high sensitivity (about 100%) and negative predictive value (over 98%), using a well-defined cut-off level (usually defined to be 500 ng/mL). Finally, with the increasing number of new D-dimer assays currently available, a lack of standardization was pointed out. As the result, both the clinical significance and the cut-off level have to be defined in prospective clinical trials, for each individual assay.     

Measurement of plasma D-dimer for diagnosis of deep venous thrombosis

Venography was performed on fifty-six patients suspected of having deep venous thrombosis (DVT) of the legs. The accuracy of the D-dimer measurement in plasma using two latex tests and an enzyme-linked immunosorbent assay (ELISA) was compared with that of usual determination of total fibrin(ogen) degradation products (FDPs) in serum with respect to the presence of DVT. The three D-dimer tests were clearly superior to the FDP assay, but only the ELISA could accurately rule out the diagnosis of DVT with a predictive value of 100% when plasma D-dimer level was less than 200 micrograms/L. However, this test cannot be used for positive diagnosis (false positive rate of 69%). Thus, plasma D-dimer measurement with ELISA allows identification of patients in whom further investigation by means of more specific tests (venography or plethysmography) is indicated in order to establish the diagnosis of DVT. In contrast to this, sensitivity of the two latex tests studied was low (60 and 76%, respectively), which makes them unsuitable for emergency screening. In addition, the potential of D-dimer dosage for diagnosis of DVT in hospitalized patients is hampered by the presence of associated conditions that are responsible for elevated plasma levels in most cases.     

Assessment of D-dimer measurement by ELISA or latex methods in deep vein thrombosis diagnosed by ultrasonic duplex scanning

In 100 consecutive patients with clinically suspected deep vein thrombosis (DVT) of the legs, plasma D-dimer measurements based on an enzyme linked immunosorbent assay (ELISA) and on latex agglutination (Diagnostica Stago) were compared to the results of real time B mode ultrasound imaging combined with Doppler examination, which in a previous study has proved to be a very accurate method competitive with venography for the diagnosis of DVT.Forty five patients had DVT identified with the ultrasonic tests. We have obtained for ELISA and latex tests of D-dimer respectively: accuracy: 60%, 56%; sensitivity: 98%, 98%; specificity: 29%, 22%; predictive value of a positive test: 53%, 50% and predictive value of a negative test: 94%, 92%. These results confirmed those of previous studies using ELISA or latex assays, with venography as a reference test.We conclude that a negative D-dimer test, defined by a value lower than 0.5 μg/ml, excludes the diagnosis of DVT in 94% of cases by ELISA method and in 92% of cases by latex method. A reduction of venography or other objective testing of the venous circulation could be obtained if these methods were not performed in the case of a negative D-dimer test. However the safety of withholding anticoagulant therapy in out patients with negative tests needs confirmation in a prospective trial.     

Latex agglutination test for adenovirus diagnosis in diarrheal disease

A commercial latex agglutination test for diagnosis of adenovirus in diarrheal disease (Adenolex, Orion Diagnostica, Finland) was evaluated by comparison with the results obtained by ELISA, electron microscopy (EM), and virus isolation. Fifty specimens originated from the diagnostic routine, and 50 were selected from a previous epidemiological study on the etiology of diarrheal disease in children. Thirteen of the 100 specimens reacted with the latex control, impairing interpretation of the results. Although the ELISA detected adenovirus antigen in 10(2) higher dilutions than the latex agglutination test, a total agreement was obtained between results by the two tests for 87 specimens including 42 positives. The two additional positives found by EM and virus isolation could not be diagnosed by the latex agglutination test. Of 37 specimens containing enteric adenoviruses (types 40 and 41), the agglutination test diagnosed all but 4 specimens containing type 41 virus. These four specimens were negative also by ELISA and adenovirus had been detected by virus isolation on the 293 cell line. The latex agglutination test gave positive results with nine specimens containing adenovirus types other than the enteric types 40 and 41. The latex agglutination test was found to be a rapid and simple method for the detection of adenovirus in diarrheal disease. Compared to ELISA and EM, the sensitivity was 100% and 95% respectively, and the specificity 100%.     

Measurement of plasma fibrin D-dimer levels with the use of a monoclonal antibody coupled to latex beads

Recently, monoclonal antibody (DD-3B6) to fibrin D-dimer was prepared and coupled to latex beads to provide a specific test (Dimertest) for fibrinolysis. The purpose of this study was to evaluate the Dimertest assay as a clinical laboratory test for the measurement of plasma fibrin D-dimer derivatives. The Dimer-test assay specifically detected 2 micrograms/mL of purified fibrin D-dimer or fibrin D-dimer/fragment E complex added to afibrinogenemic plasma but did not detect 500 micrograms/mL of either fibrinogen fragments X, D, E, or 160 micrograms/mL cross-linked fibrinogen. The fibrin(ogen) degradation product (FDP) assays of American Dade or Wellcome Diagnostics detected 5.0 micrograms/mL of fibrin D-dimer and from 1 to 10 micrograms/mL of the other FDPs. Twenty-eight percent of 150 random plasma samples assayed from hospitalized patients were positive for fibrin D-dimer derivatives. Plasma samples from 152 patients suspected of having disseminated intravascular coagulation (DIC) were assayed for serum FDP (Wellcome Diagnostics) and plasma fibrin D-dimer derivatives. Samples from 69% of patients with serum FDP levels less than 10 micrograms/mL, and more than 90% of those with serum FDP levels greater than 10 micrograms/mL, were positive for fibrin D-dimer derivatives. Dimertest results were not modified by heparin, streptokinase, freeze-thawing, or clotting plasma. Serum fibrinogen-related antigens were immunoadsorbed from Dimer-test positive sera by anti-fibrinogen antibody and formalin-fixed Cowan I strain Staphylococcus aureus. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and protein blotting with the use of monoclonal antibody DD-3B6 demonstrated a protein band with similar mobility to purified D-dimer. The measurement of plasma fibrin D-dimer derivatives by the Dimertest assay is a rapid, sensitive, and specific laboratory test for fibrinolysis. The Dimertest assay has proven to be a useful addition to the clinical laboratory and should be helpful in the diagnosis and management of patients with diseases associated with fibrinolysis.     

Incidence and possible reasons for discordant results between positive FDP and negative D-dimer latex assays in clinical specimens.

In general, FDP and D-dimer values have a correlation in clinical conditions associated with disseminated intravascular coagulation(DIC) or coagulation activation. However, there are some patients with discordant results who demonstrate elevated FDP and negative D-dimer results by latex agglutination assays. The incidence and possible reasons for the discordance between FDP and D-dimer results were investigated through simultaneous measurements (n = 763) from clinical patients with suspected DIC or coagulation activation. 24.8% (189/763) of samples with elevated FDP were negative for D-dimer assays by the latex agglutination method. Further detailed analysis on randomly-selected discordant samples (n = 41) revealed that the most common reason for the discordance was the lower sensitivity of the semiquantitative latex agglutination method for D-dimer, compared with quantitative enzyme or other latex immunoassay. The other contributing factors to the discordance were accelerated fibrinogenolysis without secondary fibrinolysis, elevated soluble fibrin monomer and rheumatoid factor.     

Direct determination of cryptococcal antigen in transthoracic needle aspirate for diagnosis of pulmonary cryptococcosis.

Pulmonary cryptococcosis causes significant morbidity and mortality in immunocompromised patients. Definitive diagnosis of pulmonary cryptococcosis is usually difficult. The use of direct determination of cryptococcal antigen in transthoracic needle aspirate to diagnose pulmonary cryptococcosis was investigated. Over a 2-year period, we studied a total of 41 patients with respiratory symptoms and pulmonary infiltrates of unknown etiology who were suspected of having pulmonary cryptococcosis. Twenty-two patients were immunocompetent patients and 19 patients were immunocompromised. A diagnosis of pulmonary cryptococcosis was based on cytological examination, culture for Cryptococcus neoformans, histopathologic examination, and clinical response to antifungal therapy. All patients underwent chest ultrasound and ultrasound-guided percutaneous transthoracic needle aspiration to obtain specimens for cryptococcal antigen determination. The presence of cryptococcal antigen was determined by the latex agglutination system (CALAS; Meridian Diagnostics, Cincinnati, Ohio). An antigen titer equal to or greater than 1:8 was considered positive. The specimens were also sent for cytological examination, fungal culture, and/or histopathologic examination. A final diagnosis of pulmonary cryptococcosis was made in eight patients. Direct determinations of cryptococcal antigen in lung aspirate were positive in all eight patients with pulmonary cryptococcosis (100% sensitivity, 97% specificity, a positive predictive value of 89%, and negative value of 100%), and there was only one false-positive in noncryptococcosis patients. The diagnostic accuracy was 97.5%. Serum cryptococcal antigen was positive in only three patients with pulmonary cryptococcosis (sensitivity, 37.5%). This study showed that direct measurement of cryptococcal antigen in lung aspirate can be a rapid and useful test for diagnosis of pulmonary cryptococcosis.     

肺栓塞CTPA间接征象诊断价值分析及临床意义

目的 评价肺栓塞患者肺动脉CT血管造影（CTPA）间接征象的诊断价值,提高肺栓塞的诊断率,减少漏诊误诊。方法 回顾性分析2015年1月~2016年1月在安徽医科大学第二附属医院就诊的99例疑诊肺栓塞患者的临床及影像学资料,以CTPA作为肺栓塞的确诊依据,分为肺栓塞组（40例）和非肺栓塞组（59例）,观察CTPA间接征象的特点,包括胸腔积液、心包积液、双侧胸膜明显增厚、右心室肥大伴室间隔偏移、肺梗死及马赛克征,对CTPA的间接征象及相关实验室检查结果（D-二聚体的定性检测）进行统计学分析。结果 肺栓塞组中胸腔积液发生率47.50%、双侧胸膜明显肥厚发生率25.00%、肺梗死发生率10.00%、右心室大伴室间隔偏移发生率12.50%、心包积液发生率5.00%、马赛克征发生率7.50%、D-二聚体阳性率100.00%,而非肺栓塞组中分别为27.10%、10.10%、0、1.70%、1.70%、0、59.30%。结论 胸腔积液、肺梗死、马赛克征及右心室肥大伴室间隔偏移等CTPA间接征象的出现,结合实验室指标D-二聚体的升高,对疑似肺栓塞患者具有提示诊断意义。     

Re-evaluation of ELISA and latex agglutination test for rheumatoid factor detection in the diagnosis of rheumatoid arthritis.

An indirect ELISA for the determination of each isotype (IgM, IgG, IgA, IgD, IgE) of rheumatoid factors (RF) was performed with sera obtained from 77 patients with either classical or definite rheumatoid arthritis (RA) and 319 controls, using rabbit IgG as the antigen. The results were compared with those of a commercial latex agglutination test, using denatured human gamma globulin as the antigen for rheumatoid factor determination. At the cut-off level at which positive results were found in less than 5% of normal controls, ELISA for IgM RF determination had sensitivity, specificity, efficiency, positive predictive value and negative predictive value of 46.75%, 98.12%, 88.13%, 85.71%, 88.41%, while those for IgA RF were 46.75%, 93.42%, 84.34%, 63.16%, 87.91% and for IgG RF were 59.74%, 92.16%, 85.86%, 64.78%, 90.46%, respectively. These indices by latex agglutination test were 83.11%, 93.73%, 91.67%, 76.19% and 95.83%, respectively. IgD RF titre greater than or equal to 1:5 was detected in 19/77 RA patients and 4/200 normal controls while IgE RF titre greater than or equal to 1:5 was detected only in 7/77 RA patients. Thus, ELISA did not appear to have any advantage over latex agglutination test for diagnosis of RA.     

Assessments of the associations of thrombus localization with accompanying disorders,risk factors,D-dimer levels,and the red cell distribution width in pulmonary embolism

OBJECTIVE:

Pulmonary embolisms occur as a wide spectrum ranging from clinically asymptomatic thrombi to massive thrombi that lead to cardiogenic shock. The purpose of this study was to determine the associations of thrombus localization with risk factors, accompanying disorders, D-dimer levels and the red blood cell distribution width in patients with pulmonary embolism.

MATERIAL AND METHODS:

In 148 patients diagnosed with pulmonary embolism, the presence and anatomical localization of the thrombus were assessed via computed tomographic pulmonary angiography. The accompanying disorders, risk factors, serum D-dimer levels, and red blood cell distribution width of the patients were retrospectively evaluated. ClinicalTrials.gov: NCT02388841.

RESULTS:

The mean age of the patients was 54±16.0 years, and 48 patients were ≥65 years of age. The most frequent accompanying disorders were chronic obstructive pulmonary disease (22%) and malignancy (10.1%), and the most frequent risk factors were recent operation (14.1%) and immobilization (18.2%). Thrombi were most frequently observed in the right pulmonary artery (37.8%). In 31% of the patients, the thrombus was localized to the main pulmonary arteries. Immobile patients exhibited a higher proportion of thrombi in the main pulmonary arteries than mobile patients. The mean D-dimer level and the mean red blood cell distribution width in the patients with thrombi in the main pulmonary arteries were higher than those in the patients with thrombi in more distal pulmonary arterial branches.

CONCLUSION:

Significant associations of proximally localized thrombi with immobilization, the D-dimer levels, and the red blood cell distribution width were observed.     

New rapid latex agglutination test for diagnosing Trichomonas vaginalis infection.

A newly developed latex agglutination test for Trichomonas vaginalis infection was compared for sensitivity, specificity, efficiency, and positive and negative predictive values with microscopy, culture, and an enzyme linked immunosorbent assay (ELISA) in the diagnosis of 395 women attending a genitourinary medicine clinic. T vaginalis infection was diagnosed in 42 (11%) women. The sensitivities of both the latex agglutination test and the ELISA were 95% compared with 74% for microscopy and 76% for culture. The latex test was specific and showed no cross reaction with a wide range of other genital tract infections. The latex agglutination test can detect antigen in both soluble and insoluble forms, and as it is simple to perform, can be undertaken during routine examination without recourse to special equipment or training. Further evaluation is required.     

Comparison of non-culture-based methods for detection of systemic fungal infections, with an emphasis on invasive Candida infections

The accepted limitations associated with classic culture techniques for the diagnosis of invasive fungal infections have lead to the emergence of many non-culture-based methods. With superior sensitivities and quicker turnaround times, non-culture-based methods may aid the diagnosis of invasive fungal infections. In this review of the diagnostic service, we assessed the performances of two antigen detection techniques (enzyme-linked immunosorbent assay [ELISA] and latex agglutination) with a molecular method for the detection of invasive Candida infection and invasive aspergillosis. The specificities for all three assays were high (> or = 97%), although the Candida PCR method had enhanced sensitivity over both ELISA and latex agglutination with values of 95%, 75%, and 25%, respectively. However, calculating significant sensitivity values for the Aspergillus detection methods was not feasible due to a low number of proven/probable cases. Despite enhanced sensitivity, the PCR method failed to detect nucleic acid in a probable case of invasive Candida infection that was detected by ELISA. In conclusion, both PCR and ELISA techniques should be used in unison to aid the detection of invasive fungal infections.     

Comparison of an in-house latex agglutination test with IgM ELISA and MAT in the diagnosis of leptospirosis

The laboratory diagnosis of leptospirosis is fraught with several problems. Isolation of Leptospira by culture has a low sensitivity and the microscopic agglutination test (MAT) is time consuming To overcome these problems, a rapid latex agglutination test (LAT) has been standardized for the detection of antileptospiral antibodies in serum samples from suspected cases of leptospirosis. We compared the efficiency of the LAT to a commercially available IgM ELISA and MAT. A total of 150 serum samples were tested by LAT, IgM ELISA, and MAT. The positivity was 26.7%, 26% and 24% respectively. The sensitivity and specificity of LAT as compared to MAT was 90.62 and 91.96% respectively. Even though LAT and ELISA showed similar results, its rapidity and simplicity made latex agglutination test more suitable as a rapid screening test.     

凝集反应对大鼠组织因子、D-二聚体及内皮细胞的影响

目的:探讨血凝素诱发的凝集反应对血浆组织因子(TF)、D-二聚体及内皮细胞的影响。方法:42只SPF级SD大鼠(雌雄不限,体重180~200 g),随机分为生理盐水对照组、不同浓度(5、10和20 g/L)植物血凝素组及灭活的植物血凝素组,每组6只。通过尾静脉向大鼠体内注入生理盐水、植物血凝素及灭活植物血凝素,用ELISA法检测大鼠血浆TF和D-二聚体的水平,透射电镜观察大鼠肺部毛细血管内皮细胞形态。结果:5、10和20g/L植物血凝素组大鼠血浆TF和D-二聚体含量均显著高于生理盐水对照组及相应浓度的灭活植物血凝素组(P0.05)。电镜下,与生理盐水对照组相比,各浓度植物血凝素组出现肺毛细血管内皮细胞损伤,表现为内皮细胞肿胀、溶解,胞质疏松,边界不清,线粒体肿胀,基膜增厚。各灭活植物血凝素组内皮细胞结构正常。结论:体内发生的凝集反应可破坏毛细血管内皮细胞,导致凝血纤溶系统紊乱。     

Right-sided EKG in pulmonary embolism

PURPOSE: To identify right-sided chest lead electrocardiographic abnormalities in acute pulmonary embolism. PATIENTS AND METHODS: Analysis of electrocardiographic changes in 100 African American patients suspected of having pulmonary embolism was made at Howard University Hospital during 2001-02 (60% women, 40% men, median age 50 years). Standard 12-lead EKGs were obtained within one hour of arrival to emergency room. Right-sided EKGs were obtained within 24 hours of onset of symptoms of pulmonary embolism. Parameters of both right- and left-sided EKGs available were measured and compared. RESULTS: Only 20% of these patients were diagnosed with pulmonary embolism. EKG changes (three of seven) suggestive of acute right ventricular strain were found in both right- and left-sided leads in 16 (80%) patients diagnosed with pulmonary embolism. These EKG changes disappeared within 24 hours of admission in 14 (87.5%) patients. Four patients with a diagnosis of pulmonary embolism had normal left-sided EKGs but the right-sided EKGs showed ST segment elevation and a qr or qs pattern (prominent q waves) in one to three of the leads V4R, V5R and V6R. These patterns were also seen in 10 of the 16 patients showing right ventricular strain pattern in their EKGs. Non-specific ST-T wave changes were seen in 20 (25%) patients not considered to have pulmonary embolism. V3R leads showed rS configuration in 90% of the patients. CONCLUSION: EKG changes in right-sided chest leads occur frequently in pulmonary embolism. The diagnostic potential of routinely recorded right-sided EKG appears to be greatest in patients with acute pulmonary embolism not manifesting typical changes in their standard 12-lead EKGs. This study also confirms previous case reports observing similar changes in the right-sided leads.     

D-二聚体联合纤维蛋白原对2型糖尿病患者急性肺栓塞的诊断价值

目的:探讨D-二聚体(D-dimer,D-D)联合纤维蛋白原(fibrinogen,FIB)对2型糖尿病内科住院患者急性肺栓塞的诊断价值.方法:选择2013年1月至2016年3月经CT肺动脉造影确诊急性肺栓塞的2型糖尿病内科住院患者及同期排除肺栓塞的2型糖尿病患者各80例,检测D-D及FIB水平.结果:在2型糖尿病急性肺栓塞患者中,D-D及FIB水平明显高于对照组.D-D和FIB单独检测诊断急性肺栓塞时的灵敏度、特异度、约登指数及ROC曲线下面积分别为:72.5％,42.5％;62.5％,91.25％;0.35,0.338;0.675(95％CI:0.597～0.747),0.669(95％CI:0.590～0.741);两者联合检测诊断急性肺栓塞时灵敏度为85.0％,特异度为60.0％,约登指数为0.45,工作特征曲线(receiver operatorcharacteristic,ROC)下面积为0.773(95％CI:0.700～0.835).D-D和FIB联合检测诊断急性肺栓塞时的ROC曲线下面积与单独检测D-D,FIB比较,差异有统计学意义(P＜0.01).结论:D-D联合FIB可作为2型糖尿病内科住院患者急性肺栓塞早期诊断时简单易行可靠的检测指标.     

Comparison of a latex agglutination assay and an enzyme-linked immunosorbent assay for detecting cholera toxin.

To determine the pandemic potential of Vibrio cholerae, one must demonstrate both the presence of O1 antigen and the production of enterotoxin (CT). Tissue culture or enzyme-linked immunosorbent assays (ELISAs) for CT have been limited to research and reference laboratories. A kit for detecting CT by reversed passive latex agglutination is now commercially available and was used to test 168 strains of V. cholerae O1 and non-O1. When compared with the routine ELISA, the latex test was 98% accurate (86 of 88) for serogroup O1 strains and 100% accurate (80 of 80) for non-O1 strains. For both O1 and non-O1 study strains, the sensitivity of the latex agglutination test was 0.97 and the specificity was 1.00 when results were compared with ELISA results. The latex test is commercially available and has the advantages of being less complicated and less time-consuming than the ELISA.     

Rapid detection of cross-linked fibrin degradation products in plasma using monoclonal antibody-coated latex particles

Conformational and structural changes on conversion of fibrinogen to fibrin and its cross-linking by Factor XIIIa lead to the development of new antigenic determinants that permit differentiation between their plasminolytic cleavage products. A monoclonal antibody (DD-3B6/22) that is specific for cross-linked fibrin derivatives containing the D dimer configuration has been used in developing a latex agglutination procedure that can detect fibrin degradation products in either plasma or serum. Fibrinogen or its degradation products do not cross-react with this antibody. Results were calibrated with an enzyme immunoassay, which used a purified D dimer standard. Plasmas from 40 normal subjects, all having D dimer levels below 250 ng/mL measured by enzyme immunoassay, were all negative by latex assay. In contrast, positive latex agglutination titers were obtained with 87 of 88 patients with demonstrated deep venous thrombosis, pulmonary embolism, or disseminated intravascular coagulation. Compared to enzyme immunoassay, latex agglutination assay is less sensitive, but this latex procedure provides a rapid and less elaborate test for elevated levels of cross-linked fibrin degradation products in patients with thrombosis. Plasma assays for fibrin degradation products are preferable to those using serum.     

A latex slide agglutination test for rapid detection of antimyeloperoxidase antibody

AIM: To develop and test a new latex slide agglutination test (MPO-LSAT) to detect antimyeloperoxidase (anti-MPO) antibody in serum. METHODS: Latex bead coating was adjusted to give maximum sensitivity by attending to latex size, MPO to latex ratio for coupling, ratio of diluted serum to MPO-latex, reaction time and temperature for coupling, and reaction time for agglutination. Inhibition studies were performed using MPO, proteinase 3, bactericidal/permeability increasing protein, and lactoferrin. RESULTS: There was very good correlation between this test and the conventional anti-MPO enzyme linked immunosorbent assay (ELISA): 81% of sera positive in the ELISA were positive by MPO-LSAT. MPO-LSAT results correlated better with IgM anti-MPO than with IgG anti-MPO. CONCLUSIONS: MPO-LSAT is a simple diagnostic test that is potentially useful in the clinical laboratory as a rapid screening tool for vasculitic diseases.