The interface of inflammation and subclinical atherosclerosis in granulomatosis with polyangiitis (Wegener's): a preliminary study

The objective of this study is to assess the relationship between inflammatory disease in granulomatosis with polyangiitis (GPA, Wegener's) and the development of subclinical atherosclerosis. A total of 46 adult patients with GPA were enrolled. Disease status was measured by Birmingham vasculitis assessment scores as modified for GPA, vasculitis damage index, disease duration, and number of relapses. Classic atherosclerotic risk factors, platelet aggregation responses, and circulating microparticle (MP) levels were recorded. All patients underwent carotid artery intima-media thickness (IMT) measurement as outcome for subclinical atherosclerosis. In univariate analyses, systolic and diastolic blood pressure, creatinine, and age were significantly associated with higher IMT (ρ values 0.37, 0.38, 0.35, and 0.054, respectively [P < 0.02 for all]). In a multiple regression model, greater number of relapses, older age at the onset of disease, and higher diastolic blood pressure were found to be associated with higher IMT (P values 0.003, <0.001, and 0.031, respectively). MP counts and platelet reactivity correlated well with disease activity in GPA. Furthermore, MPs were found to activate vascular endothelial cells and platelets in vitro. The cumulative burden of systemic inflammation in GPA correlated with the development of subclinical atherosclerosis. The correlation with subclinical atherosclerosis could be because of glucocorticoid use and not the inflammatory process in GPA, giving the inherent bias that exits with the use of glucocorticoid with each relapse. The findings of increased levels of circulating leukocyte-derived MPs and enhanced platelet reactivity during relapse suggest possible roles for MPs and platelets in disease pathogenesis and support a growing literature that links inflammation, atherosclerosis, and platelet activation. This hypothesis is further substantiated by our demonstration that MPs isolated from plasma of GPA patients can activate platelets and vascular endothelial cells.

High-resolution MRI vessel wall imaging: spatial and temporal patterns of reversible cerebral vasoconstriction syndrome and central nervous system vasculitis

BACKGROUND AND PURPOSE

High-resolution MR imaging is an emerging tool for evaluating intracranial artery disease. It has an advantage of defining vessel wall characteristics of intracranial vascular diseases. We investigated high-resolution MR imaging arterial wall characteristics of CNS vasculitis and reversible cerebral vasoconstriction syndrome to determine wall pattern changes during a follow-up period.

MATERIALS AND METHODS

We retrospectively reviewed 3T-high-resolution MR imaging vessel wall studies performed on 26 patients with a confirmed diagnosis of CNS vasculitis and reversible cerebral vasoconstriction syndrome during a follow-up period. Vessel wall imaging protocol included black-blood contrast-enhanced T1-weighted sequences with fat suppression and a saturation band, and time-of-flight MRA of the circle of Willis. Vessel wall characteristics including enhancement, wall thickening, and lumen narrowing were collected.

RESULTS

Thirteen patients with CNS vasculitis and 13 patients with reversible cerebral vasoconstriction syndrome were included. In the CNS vasculitis group, 9 patients showed smooth, concentric wall enhancement and thickening; 3 patients had smooth, eccentric wall enhancement and thickening; and 1 patient was without wall enhancement and thickening. Six of 13 patients had follow-up imaging; 4 patients showed stable smooth, concentric enhancement and thickening; and 2 patients had resoluton of initial imaging findings. In the reversible cerebral vasoconstriction syndrome group, 10 patients showed diffuse, uniform wall thickening with negligible-to-mild enhancement. Nine patients had follow-up imaging, with 8 patients showing complete resolution of the initial findings.

CONCLUSIONS

Postgadolinium 3T-high-resolution MR imaging appears to be a feasible tool in differentiating vessel wall patterns of CNS vasculitis and reversible cerebral vasoconstriction syndrome changes during a follow-up period.

Relation of the leukocyte count to recurrent cardiac events in stable patients after acute myocardial infarction

Increasing evidence implicates inflammation as a risk factor for coronary artery disease. We determined whether an elevated leukocyte count is associated with an increased risk of death or reinfarction in stable patients with a past acute myocardial infarction (AMI). The current analysis is a substudy of the Multicenter Diltiazem Postinfarction Trial, which investigated the effect of diltiazem on mortality and reinfarction in 2,466 patients hospitalized for AMI. We included 1,294 patients in whom a leukocyte count was obtained 6 months after the index AMI. The composite end point of reinfarction or death was used as the primary end point of the study and reinfarction or cardiac death was used as a secondary end point. The study population was divided into 4 quartiles (Q1, Q2, Q3, and Q4) based on the leukocyte count. During a mean follow-up period of 25 months, 163 patients reached the primary end point: 8.7%, 10.9%, 14.0%, and 16.7%, in Q1, Q2, Q3, and, Q4 respectively (p = 0.01). After adjusting for potential covariates, Cox proportional-hazards analysis revealed that an increased leukocyte count was associated with an increased risk of both the primary end point (hazard ratio/1 quartile increase in leukocyte count, 1.26; p = 0.003; 95% confidence interval 1.08 to 1.47) and secondary end point (hazard ratio, 1.18/1-quartile increase; p = 0.05; 95% confidence interval 1.00 to 1.40). In conclusion, an increased leukocyte count measured in the stable post-AMI period is associated with an increased risk of cardiac events. These findings indicate that the leukocyte count may be another marker of an atherosclerotic inflammatory process that contributes to cardiac events in postinfarction patients.

Arthritis in familial Mediterranean fever

We studied the rheumatic and various clinical manifestations of familial Mediterranean fever (FMF) in Lebanon. A retrospective review was performed of the medical records of 74 FMF patients seen at the American University of Beirut Medical Centre (AUB-MC) from 1979 to 1996. We also reviewed the medical literature from 1968 to 2000 using MEDLINE and the key words "familial Mediterranean fever" and "arthritis". Arthritis was the presenting symptom in 12 cases (16.2%). Twenty-three patients (31%) had definite arthritis during the course of the disease that was monoarticular in 16 (70%), oligoarticular in six (26%), and polyarticular (rheumatoid-like) in one (4%). Arthritis of the large joints of the knees and ankles was the most frequent articular involvement. The arthritis was transient, monoarticular, nonerosive, and nondeforming in the majority of cases. Four patients (5.4%) had chronic arthritis, with one requiring total hip replacement. As in previous reports on arthritis of FMF, the majority of FMF patients studied in Lebanon had a transient monoarticular nonerosive and nondeforming type of arthritis affecting predominantly the large joints of the lower extremities.

Electrocardiographic findings in patients with diphenhydramine overdose

QT interval prolongation and torsades de pointes ventricular tachycardia have been reported after therapeutic doses and overdosage of second generation antihistamines, such terfenadine and astemizol. Diphenhydramine (DPHM), a first generation H1 antagonist, is the most frequently used antihistaminic drug. Despite its widespread use, there are no data about cardiac action and electrocardiographic consequences of DPHM overdose. The 12-lead electrocardiograms of 126 patients (mean age 26 +/- 11 years) who had DPHM overdose were evaluated. The ingestion of large doses of DPHM (in majority of cases the dose was >500 mg) was primarily suicidal. Repolarization duration, dispersion, and morphology were evaluated in DPHM overdose patients and compared with those of healthy subjects. Mean heart rate of DPHM overdose patients was 103 +/- 25 beats/min. The QTc duration was significantly longer (453 +/- 43 vs 416 +/- 35 ms, respectively, p <0.001) and mean T-wave amplitude significantly lower (0.20 +/- 0.10 vs 0.33 +/- 0.15 mV, respectively, p <0.001) in DPHM-overdose patients than in control subjects. Dispersion of repolarization was significantly lower in DPHM-overdose patients than in control subjects (42 +/- 25 vs 52 +/- 21 ms, respectively; p = 0.003). None of the DPHM-overdose patients experienced torsades de pointes. In conclusion, DPHM overdose is associated with a significant increase in heart rate and a significant but moderate QTc prolongation. None of the studied patients, including those who had apparent QTc prolongation, experienced torsades de pointes ventricular tachycardia.