Spontaneous Achilles tendon rupture in a patient with systemic lupus erythematosus due to ischemic necrosis after methyl prednisolone pulse therapy

Spontaneous tendon rupture in a patient with systemic lupus erythematosus (SLE) is a rare but potentially disabling complication. Minor trauma, local inflammation and long term corticosteroid therapy are regarded as possible causes. However, ischemic necrosis of the tendon resulting from hypercoagulability and methyl prednisolone (MTP) pulse therapy has not been reported. We present a 20-year old female, newly diagnosed with lupus, who has high titer antiphospholipid antibodies, hyperhomocysteinemia and protein S deficiency. Her severe clinical symptoms of lupus were improved after MTP pulse therapy. Several days later, cold sensation over the right lower leg developed. On day 15 after pulse therapy, acute onset of right heel pain occurred when she was ascending stairs. Rupture of the right Achilles tendon was demonstrated by sonography and MRI. A Doppler sonography revealed narrowing and abrupt cessation of blood flow in the right popliteal artery. Heparin treatment was started. The angiography performed two days after heparinization revealed narrow caliber and decreased flow of the right tibial artery below the right ankle. Surgical repair of the tendon was successful and the pathology of the resected tendon revealed focal necrosis, degeneration and capillary proliferation. MTP pulse therapy in a lupus patient with hypercoaguable state with hyperhomocysteinemia, protein S deficiency and high titer antiphospholipid antibodies may cause spontaneous tendon rupture.     

Predictive value of D-dimer assay in superficial thrombophlebitis of the lower limbs

Objective

The negative predictive value of D-dimer (DD) assay in patients with venous thromboembolic disease is well established for deep vein thrombosis and pulmonary embolism. Little is known about the value of DD assay in patients with superficial thrombophlebitis (ST). The purpose of this study was to assess the value of DD assay in patients with ST of the lower limb.

Method

The study group was composed of 100 consecutive patients, irrespective of age. Patients with clinical manifestations suggestive of ST of the lower limbs with positive duplex color Doppler evidence confirming the diagnosis and DD assay results (Vidas D-Dimer Exclusion) within 24 hours were included in the study. Patients with thrombosis in another site in addition to the superficial vein of the lower limb, those taking anticoagulants for more than 48 hours, and those with a condition known to potentially elevate DD levels were excluded. The volume of the thrombus was determined echographically and reported as mean diameter and length.

Results

Sixty-two women and 38 men were included. Mean age (± 5) was 58 years ± 13.48 (range 18–90; median: 57). The ST involved the Great saphenous (n = 74), the small saphenous (n = 11) or another vein (n = 15). Mean thrombus volume was 4453 mm³ ± 7101 (range 94–38484; median: 1751). Mean DD level was 829 ng/ml ± 516.72 (range 100–2567; median: 715.5). DD assay was negative (< 500 ng/ml) in 32 patients (32%) and positive in 68 (68%). For these three items, there was no significant difference between ST with and without varicose veins. DD assay was always positive (≥ 500 ng/ml) in all patients aged over 70 years (n = 22). In patients aged less than 70 years (n = 78), DD assay was positive in 46 (59%) and negative in 32 (41%). DD level was positively correlated with thrombus volume in patients aged less than 70 years (P < 0.0001). ROC analysis, sensitivity as a function of specificity by thrombus volume for the entire population, determined the usefulness of a negative DD assay. Considering the critical threshold at 5914 mm³, sensitivity was 1.0 (95CI 0.89–1.0), with 0.29 specificity (95CI 0.19–0.42), 1.00 negative predictive value and 0.75 positive predictive value. However, the thrombus volume was less than this threshold value in three of the nine cases of ST with extension to the terminal portion of the saphenous.

Conclusion

A positive DD assay was observed in 68% of patients with ST, with no significant difference with or without varicose veins. The test was positive in all patients aged over 70 years and in 59% of those aged under 70 years. There was a correlation between DD level and thrombus volume, yielding a threshold volume (5914 m³) above which all DD tests were positive. Nevertheless, this threshold volume was too great to include all ST extending to the terminal portion of the saphenous. Measurement of DD level is thus not contributive to the diagnosis of ST.     

Use of equivocal zone in interpretation of results of the amplified mycobacterium tuberculosis direct test for diagnosis of tuberculosis

The sensitivity and specificity of the Amplified Mycobacterium Tuberculosis Direct (AMTD) test, evaluated with 1,363 respiratory samples (128 from tuberculous patients), were 92.97 and 98.7%, respectively. When an equivocal zone (30,000 to 1,000,000 relative light units [RLU]) was used instead of a 30,000-RLU cutoff, the sensitivity and specificity of the AMTD test were 92.97 and 100%, respectively.     

Evaluation of the automated phoenix system for potential routine use in the clinical microbiology laboratory

A comparative study was designed to evaluate the identification (ID) and antimicrobial susceptibility testing (AST) performances of the BD Phoenix Automated Microbiology System (Becton Dickinson Diagnostic Systems [BD], Pont de Claix, France). A total of 305 single clinical isolates were collected, and comparisons were made with routine manual methods in use in our microbiology laboratories. The percentages of correct IDs were 93.3, 89.4, 91.8, and 85.7% for enterobacteria, nonfermenting gram-negative bacilli, staphylococci, and streptococci-enterococci, respectively. The median ID time was 3 h, and the median time for AST was 10 h 30 min. AST results showed variable percentages of errors for the different antibiotics. None of the enterobacteria and 0.3% of Pseudomonas aeruginosa isolates showed a very major error (VME). Only one strain of Staphylococcus aureus showed a VME with oxacillin. We demonstrate here the efficiency of the Phoenix system, which can be used for the majority of strains encountered in a university-based laboratory, for ID and AST.     

IFNgamma and antibody responses among French nurses during a tuberculosis contact tracing investigation

Study

A comparative study which compared PPD skin testing inserted according to the French Society of Pneumology's recommendations and interferon gamma release assay (IGRA) (QuantiFERON^® TB Gold In-tube, QF–TB–IT, Cellestis, Carnegie, Australia) was performed during a tuberculosis contact investigation in our hospital.

Patients

Nineteen French health-care workers (HCWs) volunteered to participate. All of the HCW enrolled were BCG vaccinated and had a normal chest X-ray at entry.

Results

Among the HCW, 68.4% were TST positive. By comparison, only 31.6% had a positive QF-TB-IT result. We took advantage of the negative tube and the corresponding plasma for antibody detection by ELISA. None were ELISA positive. Fourteen HCWs were followed up. None of the HCWs accepted a course of antiTB chemoprophylaxis. Despite the difficulty in establishing a trend in kinetics, we saw the complexity of interpretation of a dynamic T-cell response after contact with an index case.

Conclusion

This initial and first French picture provides us with the observation that only 44% of TST-positive HCW were IGRA positive, and the IGRA test allowed the detection of LTBI in two TST negative HCWs.     

Heterogeneity in the granulomatous response to mycobacterial infection in patients with defined genetic mutations in the interleukin 12-dependent interferon-gamma production pathway

Patients with genetic lesions in the Type-1 cytokine/cytokine receptor pathway exhibit a selective susceptibility to severe infections with poorly pathogenic mycobacteria and non-typhi salmonella spp. These experiments of nature demonstrate that IL-12-dependent IFNgamma production is critical for granuloma formation and therefore host immunity against such pathogens. The essential role of granuloma formation for protective immunity to these organisms is emphasized by the differing granuloma forming capabilities and resultant clinical sequelae observed in these patients which seems to reflect their ability to produce or respond to IFNgamma (Fig. 9). At one pole of this spectrum, represented by the complete IFNgammaR1/2 deficient patients, there is a complete absence of mature granuloma formation, whereas with the less severe mutations (i.e. partial IFNgammaR1/2, complete IL-12p40 and complete IL-12Rbeta1 deficiency), granuloma formation is very heterogenous with wide variations in composition being observed. This suggests that in the latter individuals, who produce partial but suboptimal IFNgamma responses, other influences, including pathogen virulence and host genotype may also affect the type and scale of the cellular response elicited.     

Functional GABA(B) receptors are expressed at the cone photoreceptor terminals in bullfrog retina

GABA(B) receptors at the cone terminals in bullfrog retina were characterized by immunocytochemical and whole-cell patch clamp techniques in retinal slice preparations. Somata, axons and synaptic terminals (pedicles) of cones were both GABA(B) receptor (GABA(B)R) 1 and GABA(B)R2 immunoreactive. Physiologically, barium/calcium currents of cones to voltage steps were significantly reduced in size when GABA was puffed to cone terminals in the presence of picrotoxin that is supposed to block both GABA(A) and GABA(C) receptors. Similar reduction in barium currents was obtained with puff application of baclofen to cone terminals. These results suggest the presence of functional GABA(B) receptors at the bullfrog cone terminals. Suppression of barium currents of cones by baclofen was dose-dependent. Moreover, barium currents of cones were potentiated by background illumination, as compared with those recorded in the dark. 6,7-Dinitroquinoxaline-2,3-dione, an antagonist of non-NMDA receptors that hyperpolarizes horizontal cells and reduces GABA release from these cells, and saclofen, a GABA(B) receptor antagonist, both potentiated barium currents of cones in the dark, thereby mimicking the effects of background illumination. It is suggested that changes in calcium influx into the cone synaptic terminals due to activation of GABA(B) receptors may provide a negative feedback mechanism for regulating signal transmission between cones and second-order neurons in the retina by modifying the amount of glutamate released from the cones.