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OBJECTIVE: (18)F-fluorodeoxyglucose-positron emission tomography (FDG-PET) scanning has been proposed as a new way of assessing disease activity in Takayasu arteritis (TA), but previous studies have used the nonvalidated National Institutes of Health (NIH) global activity criteria, and thus might be biased. This study was undertaken to determine the value of PET scanning for assessment of disease activity in TA, by comparing PET scan data with clinical, biologic, and magnetic resonance imaging (MRI) data assessed separately. METHODS: Twenty-eight patients with TA (according to the American College of Rheumatology criteria) underwent a total of 40 PET scans. Images were reviewed by 2 pairs of independent nuclear medicine physicians and assessed for pattern and intensity of vascular uptake. TA activity data were obtained within 15 days of the PET scans. RESULTS: PET scanning revealed abnormal vascular uptake in 47% of the 40 examinations. The uptake intensity grade was 0 in 7 scans, grade 1 in 7 scans, grade 2 in 13 scans, and grade 3 in 13 scans. Morphologic analysis was conducted by grading the pattern of the vascular uptake as diffuse (73%), segmental (20%), or focal (13%). There was a trend toward an association between clinically active disease and the semiquantitative assessment of FDG uptake (P = 0.08). We found no statistical association between levels of acute-phase reactants and intensity of uptake. There was no significant association between the semiquantitative assessment of FDG uptake and the presence of vascular wall thickening (P = 0.23), gadolinium uptake (P = 0.73), or the presence of vascular wall edema (P = 0.56). CONCLUSION: Our findings indicate that there is no association between FDG vascular uptake intensity and clinical, biologic, or MRI assessment of disease activity. Previous studies using the nonvalidated NIH global activity criteria are likely biased. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To study the possible relationship between whole-blood hydroxychloroquine (HCQ) concentrations and clinical efficacy of HCQ in patients with systemic lupus erythematosus (SLE). METHODS: Whole-blood HCQ concentrations were measured, under blinded conditions, in 143 unselected patients with SLE who had been receiving HCQ 400 mg daily for at least 6 months. The relationship of these concentrations to current disease activity and to subsequent exacerbations during 6 months of followup was investigated. RESULTS: At baseline, 23 patients had active disease (mean +/- SD SLE Disease Activity Index 12.4 +/- 7.5). The mean whole-blood HCQ concentration in this group was significantly lower than that in the 120 patients with inactive disease (694 +/- 448 ng/ml versus 1,079 +/- 526 ng/ml; P = 0.001). Among the 120 patients who had inactive disease at baseline, the mean HCQ concentration at baseline in the 14 (12%) who had disease exacerbations during followup was significantly lower than that in the patients whose disease remained inactive. Multivariate logistic regression showed that the HCQ concentration was the only predictor of exacerbation (odds ratio 0.4 [95% confidence interval 0.18-0.85], P = 0.01). Receiver operating characteristic curve analysis showed that a whole-blood HCQ concentration cutoff of 1,000 ng/ml had a negative predictive value of 96% for exacerbation during followup. CONCLUSION: Low whole-blood HCQ concentrations are associated with SLE disease activity and are a strong predictor of disease exacerbation. Regular drug assaying and individual tailoring of treatment might help to improve the efficacy of HCQ treatment in patients with SLE. [ABSTRACT FROM AUTHOR]

Arterial thrombotic events, thrombocytopenia, and hemolytic anemia with schistocytes may be encountered in the setting of both thrombotic thrombocytopenic purpura (TTP) and primary antiphospholipid syndrome (APS). We report 2 cases of TTP occurring in patients with definite primary APS. We also describe the results of tests for ADAMTS-13 activity in 20 consecutive patients with primary APS, as well as tests for antiphospholipid antibodies in 26 patients who had TTP, severe ADAMTS-13 deficiency, and ADAMTS-13-inhibiting antibodies. In both of the patients with primary APS and TTP, ADAMTS-13 activity was undetectable, and ADAMTS-13-inhibiting antibodies were present. None of the 26 patients with TTP and severe ADAMTS-13 deficiency was positive for the lupus anticoagulant. One of these patients had a low level of anticardiolipin antibodies (22 IgG phospholipid units). In the 20 patients with primary APS, mean ADAMTS-13 activity was 116% (range 44-250%), and no severe deficiency (<5%) was observed. Our findings suggest that primary APS must be added to the list of autoimmune disorders that can be complicated by TTP. [ABSTRACT FROM AUTHOR]

OBJECTIVE: Aside from congenital heart block (CHB), sinus bradycardia and prolongation of the corrected QT (QTc) interval have been reported in infants born to mothers with anti-SSA antibodies. To assess the pathologic nature of these manifestations, this study focused on electrocardiographic (EKG) variations in these children, comparing them with findings in a control group. METHODS: We studied 165 consecutive pregnancies in 106 anti-SSA-positive women with connective tissue diseases (CTDs). EKGs obtained on 58 children of this group were compared with those obtained on 85 infants born to mothers with CTD who were negative for both anti-SSA and anti-SSB. RESULTS: No statistically significant difference was seen between the 2 study groups with regard to gestational age, prematurity, birth weight, age of the children at the time of EKG, age of the mothers, or treatments received by the mothers during their pregnancies. Seven of 137 children developed cutaneous neonatal lupus syndrome; 1 child developed CHB (CHB risk of 1 in 99 [1%] if only the first prospectively observed pregnancy in women without a history of CHB is included in the analysis). For EKGs recorded during the first 2 months of life, the mean +/- SD PR interval was 96 +/- 16 msec in the anti-SSA-positive group and 96 +/- 13 msec in the anti-SSA-negative group (P = 0.84), with mean QTc values of 397 +/- 27 and 395 +/- 25 msec (P = 0.57) and mean heart rates of 141 +/- 23 and 137 +/- 21 beats per minute (P = 0.20), respectively. No difference in the PR interval, QTc interval, or heart rate was observed for EKGs obtained between 2 and 4 months of life. When EKGs obtained at 0-2 months were compared with those obtained at 2-4 months, a physiologic prolongation of the QTc interval was observed in both study groups. No sudden infant death or symptomatic arrhythmia occurred during the first year of life. CONCLUSION: The EKG findings in children of anti-SSA-positive and anti-SSA-negative mothers were not significantly different. Our results suggest that the prolongation of the QTc interval and sinus bradycardia that have recently been reported in children of mothers with anti-SSA antibodies occur independently of the anti-SSA antibodies. The pathologic nature of these EKG variations was not confirmed by our controlled study. Copyright 2004 American College of Rheumatology [ABSTRACT FROM AUTHOR]