Differences in clinical manifestations and increased severity of systemic lupus erythematosus between two groups of Hispanics: European Caucasians versus Latin American mestizos (data from the RELESSER registry)

Background

Systemic lupus erythematosus (SLE) is regarded as a prototype autoimmune disease because it can serve as a means for studying differences between ethnic minorities and sex. Traditionally, all Hispanics have been bracketed within the same ethnic group, but there are differences between Hispanics from Spain and those from Latin America, not to mention other Spanish-speaking populations.

Objectives

This study aimed to determine the demographic and clinical characteristics, severity, activity, damage, mortality and co-morbidity of SLE in Hispanics belonging to the two ethnic groups resident in Spain, and to identify any differences.

Methods

This was an observational, multi-centre, retrospective study. The demographic and clinical variables of patients with SLE from 45 rheumatology units were collected. The study was conducted in accordance with Good Clinical Practice guidelines. Hispanic patients from the registry were divided into two groups: Spaniards or European Caucasians (EC) and Latin American mestizos (LAM). Comparative univariate and multivariate statistical analyses were carried out.

Results

A total of 3490 SLE patients were included, 90% of whom were female; 3305 (92%) EC and 185 (5%) LAM. LAM patients experienced their first lupus symptoms four years earlier than EC patients and were diagnosed and included in the registry younger, and their SLE was of a shorter duration. The time in months from the first SLE symptoms to diagnosis was longer in EC patients, as were the follow-up periods. LAM patients exhibited higher prevalence rates of myositis, haemolytic anaemia and nephritis, but there were no differences in histological type or serositis. Anti-Sm, anti-Ro and anti-RNP antibodies were more frequently found in LAM patients. LAM patients also had higher levels of disease activity, severity and hospital admissions. However, there were no differences in damage index, mortality or co-morbidity index. In the multivariate analysis, after adjusting for confounders, in several models the odds ratio (95% confidence interval) for a Katz severity index >3 in LAM patients was 1.45 (1.038–2.026; p = 0.02). This difference did not extend to activity levels (i.e. SLEDAI >3; 0.98 (0.30–1.66)).

Conclusion

SLE in Hispanic EC patients showed clinical differences compared to Hispanic LAM patients. The latter more frequently suffered nephritis and higher severity indices. This study shows that where lupus is concerned, not all Hispanics are equal.

Treatment of chronic gout in patients with renal function impairment: an open, randomized, actively controlled study

Treatment of gout and hyperuricemia can be difficult in patients with chronic renal failure. At present, there is no study available comparing the efficacy of the most widely used agent, allopurinol, and the uricosuric benzbromarone for the control of hyperuricemia in patients with renal insufficiency. We describe an open, randomized, actively controlled, comparative trial in patients with clearance of creatinine from 20 to 80 mL/ min/1.73 m(2). Patients were randomized to take benzbromarone (100-200 mg/day) or allopurinol (100-300 mg/day). Outcome variables were the following: reduction of serum urate (Sur), Sur & tl; 6 mg/dL (357 micromol/L), reduction of gouty bouts and reduction of tophi. During 9-24 months of follow-up 36 patients were studied.The reduction of Sur was higher with benzbromarone, and only 1 of 17 patients taking benzbromarone did not achieve Sur < 6 mg/dL versus 7 of 19 taking allopurinol. Patients who did not reach optimal Sur levels with allopurinol were more frequently taking diuretics and showed lower fractional excretion of urate and higher initial Sur levels than patients with proper control of Sur. Seven patients with suboptimal control of serum urate were changed to benzbromarone 100 mg/day, which showed efficacy similar in those who were initially randomized to benzbromarone. A reduction of gouty bouts and size of tophi was observed after proper control of Sur. Allopurinol is effective in controlling hyperuricemia, but patients with higher initial Sur levels or taking concomitant diuretic therapy are less prone to reach therapeutic goals.Benzbromarone is useful for the control of hyperuricemia in patients with renal insufficiency even with concomitant diuretic administration; patients benefited include those who previously had no improvement by taking allopurinol.

Efficacy of radiosynovectomy of the knee in rheumatoid arthritis: evaluation with magnetic resonance imaging

The intra-articular injection of a radiopharmaceutical agent (radiosynovectomy) produces a reduction of the synovial inflammatory process. The inflammed synovial membrane can be identified with magnetic resonance imaging after the intravenous administration of gadolinium (MRI-Gd). A 6-month prospective study was carried out in 10 patients with rheumatoid arthritis after radiosynovectomy of the knee. The efficacy was evaluated with clinical parameters and MRI-Gd. A progressive amelioration of synovial effusion, pain, articular range of mobility, total leucocytes count in synovial fluid and synovial membrane thickness through MRI-Gd was observed. The global efficacy was considered to be good in six patients, fair in three and bad in one. The study shows for the first time that MRI-Gd allows the evaluation of the response of the synovial membrane to radiosynovectomy.

Efficacy of allopurinol and benzbromarone for the control of hyperuricaemia. A pathogenic approach to the treatment of primary chronic gout

OBJECTIVES

To study the efficacy of allopurinol and benzbromarone to reduce serum urate concentrations in patients with primary chronic gout.

METHODS

Prospective, parallel, open study of 86 consecutive male patients with primary chronic gout. Forty nine patients (26 normal excretors and 23 under excretors) were given allopurinol 300 mg/day and 37 under excretors benzbromarone 100 mg/day. After achieving steady plasma urate concentrations with such doses, treatment was then adjusted to obtain optimal plasmatic urate concentrations (under 6 mg/dl).

RESULTS

Patients receiving allopurinol 300 mg/day showed a mean reduction of plasmatic urate of 2.75 mg/dl (from 8.60 to 5.85 mg/dl) and 3.34 mg/dl (from 9.10 to 5.76 mg/dl) in normal excretors and under excretors respectively. Patients receiving benzbromarone 100 mg/day achieved a reduction of plasmatic urate of 5.04 mg/dl (from 8.58 to 3.54 mg/dl). Fifty three per cent of patients receiving allopurinol and 100% receiving benzbromarone achieved optimal plasma urate concentrations at such doses. The patients with poor results with allopurinol 300 mg/day achieved a proper plasma urate concentration with allopurinol 450 to 600 mg/day, the mean final dose being 372 mg/day. Renal function improved and no case of renal lithiasis was observed among benzbromarone treated patients, whose mean final dose was 76 mg/day.

CONCLUSION

Benzbromarone is very effective to control plasma urate concentrations at doses ranging from 50 to 100 mg/day. Uricosuric treatment is a suitable approach to the treatment of patients with gout who show underexcretion of urate.

High prevalence of undetected carpal tunnel syndrome in patients with fibromyalgia syndrome

OBJECTIVE

To assess the prevalence of carpal tunnel syndrome (CTS) in patients with fibromyalgia syndrome (FM).

METHODS

A series of 206 consecutive patients with FM was evaluated for CTS in an unblinded, uncontrolled study. Sixty patients with dermatomal paresthesia in the fingers enervated by the median nerve were evaluated with electromyogram and nerve conduction velocity studies (EMG/NCV).

RESULTS

Thirty-three patients showed EMG/NCV findings diagnostic for CTS (16% of the 206 cases, 55% of the 60 EMG studies). Only 2 of the 33 patients with CTS had been diagnosed before rheumatologic evaluation. We compared our results with those reported for women in the general population. The overall prevalence of CTS in women was higher (16 vs 10.2%), but not statistically different. However, in our series, there was a clear difference in the higher rate of undetected CTS in women with FM compared to that of the general population (14.1 vs 6.7%) (p < 0.01).

CONCLUSION

(1) CTS is at least as common in patients with FM as in the general population, contrary to that reported in retrospective studies; (2) the rate of underdiagnosed CTS in women with FM is much higher than the rate reported in the general population; (3) NCV studies may be necessary to evaluate underdiagnosed CTS in patients with FM and dermatomal paresthesia in their hands.