[Evaluation of a test for rapid detection of D-dimers for the exclusion of the diagnosis of venous thrombosis]

OBJECTIVES

The SimpliRED whole blood D-dimer assay for exclusion of deep venous thrombosis in symptomatic outpatient appears to be a simple and rapid method; we wanted to confirm its reliability.

METHODS

Fifty consecutive outpatients (mean age 57, range 20 to 89) referred to our department between September and December 1996, for clinically suspected deep venous thrombosis (DVT) were included. Hospitalized patients were excluded as well as patients under anticoagulant and pregnant women. DVT was diagnosed with our usual strategy of compression ultrasonography at the levels of the common femoral, the superficial femoral and the popliteal veins including the exploration of sural and saphenous veins. The D-dimer assay was performed, according to the manufacturer recommendation, blindly by a physician unaware of the results of ultrasonography within one hour.

RESULTS

Eight of nineteen patients with DVT had a normal D-dimer test result Four had a sural DVT, but four had a proximal DVT. Furthermore four patients with normal D-dimers had superficial venous thrombosis.

CONCLUSIONS

Our series does not confirm the high sensitivity and negative predictive value reported previously. To date it is premature to propose this assay as a first line test in the therapeutic management of patients with suspected DVT.

[Distal gangrene and cryoglobulinemia related to hepatitis C virus infection with presence of anticardiolipin antibodies]

We report the case of a 63-year old women with toe gangrene, peripheral polyneuropathy, polyarthritis, histologically proven necrotizing vasculitis, in association with type III mixed cryoglobulinemia and hepatitis C virus (HCV) infection. Raised anticardiolipin antibodies (aCL) were found, without beta 2-glycoprotein I. HCV infection is associated with mixed cryoglobulinemia which can cause a vasculitis affecting various organs. The pathogenesis of production and clinical significance of aCL could be associated in this case with HCV infection.

The urinary metanephrine-to-creatinine ratio for the diagnosis of pheochromocytoma

OBJECTIVE

To compare the operating characteristics of two tests for diagnosing pheochromocytoma: 1) measurement of the ratio between urinary metanephrine and creatinine levels and 2) measurement of urinary metanephrine levels alone. A second objective was to ascertain the reasons for false-positive test results.

DESIGN

Cross-sectional study.

SETTING

Hypertension referral center.

PATIENTS

1013 patients referred for hypertension and tested for pheochromocytoma.

MEASUREMENTS

24-hour urinary levels of metanephrine (measured using liquid chromatography) and creatinine. The presence of pheochromocytoma was confirmed at surgery. In patients with positive test results, the absence of pheochromocytoma was documented by negative results of retests and imaging procedures.

RESULTS

Of 58 patients with increased metanephrine levels or increased metanephrine-to-creatinine ratios, 20 had pheochromocytoma and 38 did not. Of the 38 patients without pheochromocytoma, 15 had high metanephrine levels but normal metanephrine-to-creatinine ratios. The respective operating characteristics of measurement of urinary metanephrine levels and measurement of the metanephrine-to-creatinine ratio were as follows: sensitivity, 95% and 100%; specificity, 98% and 98%; positive predictive value, 46% and 47%; and negative predictive value, 100% and 100%. In 13 of the 23 patients who had a high metanephrine-to-creatinine ratio, various acute events may have caused hypersecretion of catecholamines.

CONCLUSIONS

Measurement of the metanephrine-to-creatinine ratio is a sensitive and specific test for pheochromocytoma. However, acute events may increase urinary metanephrine excretion to the level that occurs with tumors.

The complete exon-intron structure of the 156-kb human gene NFKB1, which encodes the p105 and p50 proteins of transcription factors NF-kappa B and I kappa B-gamma: implications for NF-kappa B-mediated signal transduction

The NFKB1 gene encodes three proteins of the NF-kappa B/Rel and I kappa B families: p105, p50, and (in mouse) I kappa B-gamma. We determined the complete genomic structure of human NFKB1. NFKB1 spans 156 kb and has 24 exons with introns varying between 40,000 and 323 bp in length. Although NFKB2, which encodes p100 and p52, also has 24 exons and has a comparable exon-intron structure, it is 20 times shorter (8 kb; Fracchiola et al. (1993) Oncogene 8, 2839-2845) than NFKB1. We propose that the long size of NFKB1 is important for transient activation of NF-kappa B complexes containing p50. I kappa B-gamma corresponds to the carboxyl-terminal half of p105. DNA sequence analysis showed that the 3'-end of human intron 11 and the 5'-end of exon 12 of NFKB1 are colinear with the 5'-untranslated region of mouse I kappa B-gamma cDNA. I kappa B-gamma is thus likely to be generated by transcription starting within intron 11 and not by alternative splicing of the mouse mRNA encoding p105 and p50.