Impact of the positive pathergy test on the performance of classification/diagnosis criteria for Behcet's disease.

BACKGROUND: The only diagnostic test that currently exists for Behcet's disease (BD) is the pathergy test. A positive pathergy test (PPT) is an important component of many of the 16 sets of classification/diagnosis criteria used to diagnose BD. The aim of this study was to determine the importance of a PTT in the performance of the diagnosis/classification criteria for BD. PATIENTS AND METHODS: All patients listed in the BD registry of the Rheumatology Research Center, Tehran (6,727) and 4,648 BD controls were enrolled in the study. The diagnosis was clinical when no other diagnosis could explain the patient's manifestations. The criteria were tested with and without PPT results. Sensitivity, specificity, and accuracy were calculated. RESULTS: Without PPT, all sets of criteria lost sensitivity, gained specificity, and lost accuracy, with the exception of the Cheng-Zhang criteria. The largest loss in sensitivity was for the Hubault-Hamza (35 %) and Dilsen (17.3 %) criteria; the least was for the Curth (1.9 %) and ICBD (6.5 %) criteria. The largest gain on specificity was for the Dilsen (4.7 %) and Curth (3.1 %) criteria; the least was for the Japan (0.1 %) and Japan revised (0.1 %) criteria. The greatest loss in accuracy was for the Hubault-Hamza (20.4 %) and Dilsen revised (9.3 %) criteria; the least was for the ICBD (3.6 %), while Curth gained 0.3 %. CONCLUSION: Without PPT as a criterion for the diagnosis of BD, the sensitivity and accuracy of the sets of classification/diagnosis criteria decrease, while the specificity improves.

Behcet's disease: is there a gender influence on clinical manifestations?

AIM: In Behcet's disease (BD), it is customary to believe that men are more affected than women, major organs are more involved in men, and they have worse outcomes. The male-to-female ratio is reported from 5.37 to 1 (Egypt), to 0.38 to 1 (US). If in the majority of reports BD was seen more frequently in men, in some others it was more frequent in women. The aim of this study was to examine a large cohort of patients, in whom manifestations were gender related, and to examine the strength of associations and their clinical relevance. PATIENTS AND METHODS: All patients of the BD registry, Rheumatology Research Center, Tehran University of Medical Sciences, entered the study (6702 patients). The percentage of 95 items was calculated in both genders (with their 95% confidence intervals), and were compared together by the chi-squared test. Odds ratio (OR) and relative risk (RR) were also calculated. RESULTS: Forty-three out of 95 items were gender-related (29 for males, 14 for females) with a statistically significant difference by chi-squared. Significant OR (confidence interval not reaching 1) was found for 79 items. However, clinically significant OR (2 or more for men and 0.5 or less for women) showed an association only with 16 items; five with females and 11 with males. The most important was vascular involvement. CONCLUSION: No strong association (OR of 2 or more) was found between the male gender and major organ involvement, except for vascular lesions.

Diagnostic value of pathergy test in Behcet's disease according to the change of incidence over the time.

Pathergy test (PT) is used for the diagnosis of Behcet's disease (BD). It is a criterion in many classification/diagnosis criteria. PT is mainly seen in BD but can be seen in other conditions too. PT has been reported with high frequency from most countries along the Silk Road. The sensitivity of pathergy phenomenon (PP) is declining over the time. The aim of this study was to look for the diagnostic value of PT in the past and at the present time. The BD registry (Rheumatology Research Center, Tehran University of Medical Sciences) has the data of 6,607 BD and 4,292 control patients. Patients and controls were divided in four groups of 1,650 BD and 1,073 controls. Sensitivity, specificity, positive and negative predictive value (PPV-NPV), positive and negative likelihood ratio (PLR-NLR), diagnostic odds ratio (DOR), and Youden's index (YI) were calculated for each group. The first and the fourth quartiles were compared. Sensitivity of PT decreased from 64.2% (first quartile) to 35.8% (fourth quartile). Specificity improved from 86.6% to 98.4%. PPV improved from 82.7% to 95.7%. NPV decreased from 82.7% to 60.5%. PLR improved from 4.8 to 22.4, while NLR deteriorated from 0.41 to 0.65. DOR improved from 11.6 to 34.3. Yuden's index worsened from 0.5 to 0.34. Although sensitivity of PP decreased, the increase of specificity is a plus value for diagnosis. As a result, PPV, PLR, and DOR improved, while NPR, NLR, and YI deteriorated. Although the pathergy test lost its sensitivity during the past 35 years, it has not lost its value as a diagnostic test, improving many of its characteristics. In a practical view, the chances of getting a positive test have decreased over the time. However, a positive test is rather the synonym of Behcet's disease, with a probability of 98.4%.

Behcet's disease in Iran: analysis of 6500 cases.

OBJECTIVE: To identify the clinical picture of Behcet's disease in a large cohort of patients (6500) in Iran, over a period of 35 years, and compare them with other large series from around the world. METHODS: Patients with Behcet's disease from all over Iran were seen in the Behcet's Disease Research Unit by a multidisciplinary team (rheumatologists, dermatologists, and ophthalmologists). Diagnosis was based on 'expert opinion'. Data were collected on a standardized data sheet (105 items), and stored in an electronic database. Data were updated at each follow-up. RESULTS: Male to female ratio was 1.22 : .00. The mean age at onset was 26 years ± 11.3. The frequency of symptoms were: oral aphthosis 97.3%, genital aphthosis 64.6%, skin manifestations 64.9% (pseudofolliculitis 54.5%, erythema nodosum 22.5%, other lesions 7%), pathergy phenomenon 52.5%, ophthalmologic manifes-tations 56.8% (anterior uveitis 41.2%, posterior uveitis 44.9%, retinal vasculitis 32.1%), joint manifestations 37.4% (arthralgia 17.2%, monoarticular arthritis 7.6%, oligoarthritis 16.8%, ankylosing spondylitis 2%), neurological manifestations 3.8% (central manifestations 3.5%, mononeuritis multiplex 0.3%), gastrointestinal manifestations 7.4%, vascular involvement 8.3% (phlebitis 5.7%, superficial phlebitis 2.2%, large vein thrombosis 1.1%, arterial thrombosis 0.154%, aneurysm 0.5%), epididymitis 4.7%, cardiac involvement 0.6%, and pulmonary involvement 0.9%. Sedimentation rate was normal in 46.5% of patients. Abnormal urine sediment was detected in 12.2%. HLA-B5 was present in 53.3% and HLA-B51 in 47.9% of patients. CONCLUSION: Behcet's disease is mainly seen in young people. The most frequent symptoms are mucocutaneous, ocular and joint manifestations. Comparison with large series did not show major differences.