Dyspnea in ambulatory patients with SLE: prevalence, severity, and correlation with incremental exercise testing

OBJECTIVE

We sought to determine the prevalence and severity of dyspnea, and to correlate dyspnea with clinical features and exercise limitation in ambulatory patients with systemic lupus erythematosus (SLE).

METHODS

Twenty-five consecutive patients were evaluated with a validated pulmonary questionnaire, chest radiograph, 2-dimensional echocardiography, resting pulmonary function tests, and incremental exercise testing.

RESULTS

Dyspnea was reported by 60% (95% CI 39-79) of patients; 20% (95% CI 7-40) had severe dyspnea (inability to dress without dyspnea) and 12% (95% CI 3-31) had moderate dyspnea (dyspnea after walking 100 yards). Compared to patients without dyspnea, patients with dyspnea were more likely to have had a history of clinical lupus involving the lung (80 vs 40%, p = 0.05), a lower total lung capacity (77.5 vs 94.8%, p = 0.002), and a reduced maximum oxygen consumption (VO2max of 53.4 vs 67.7%, p = 0.01). Patients with severe dyspnea and patients without dyspnea did not differ in duration of prednisone use, activity of disease, weight, or in frequency of Raynaud's phenomenon (p > 0.05). Only 4% of all patients had abnormal left ventricular motion on 2-dimensional echo; patients with moderate or severe dyspnea had normal left ventricular motion. Of the 5 patients with severe dyspnea, 4 (80%) had restrictive lung disease and 1 (20%) had an isolated diffusion defect. All patients with dyspnea had an abnormal exercise test, but so did 9/10 without dyspnea (p > 0.05). Severity of dyspnea correlated highly with maximum exercise tolerance measured by VO2max (R2 = 0.51, p = 0.0001).

CONCLUSION

In ambulatory patients with SLE, dyspnea is common, frequently disabling, associated with a history of lupus involvement of the lung, and correlates highly with objective measures of exercise limitation.

Oral cimetidine improves the accuracy and precision of creatinine clearance in lupus nephritis

OBJECTIVE

To determine whether short-term use of oral cimetidine improves the precision of creatinine clearance (CCr) and reduces the overestimation of glomerular filtration rate (GFR) that occurs with this test in patients with lupus nephritis (because creatinine is secreted by injured renal tubular cells).

DESIGN

Double-blind, placebo-controlled, crossover clinical trial.

PATIENTS

Thirteen patients with lupus nephritis with mild renal insufficiency (mean serum creatinine, 230 mumol/L [2.6 mg/dL]; median, 106 mumol/L [1.2 mg/dL]).

INTERVENTIONS

Patients were given placebo or cimetidine tablets, 400 mg four times daily for 2 days, with ambulatory 24-hour urine collection during the second 24 hours ("outpatient study"). Simultaneous 4-hour technetium-99-diethylenetriamine penta-acetic acid (Tc99-DTPA) and CCrs were measured immediately after each 24-hour collection ("simultaneous study").

MEASUREMENTS AND MAIN RESULTS

Use of cimetidine improved the accuracy of CCr, as measured by the CDTPA-to-CCr ratio (1.07 [cimetidine] compared with 1.33 [placebo]; P less than 0.05). Cimetidine use also improved the precision of CCr (P less than 0.05). In addition, when compared with standard clinical estimators of GFR, creatinine clearance with cimetidine rendered the most precise estimates of GFR and explained more of the variation in GFR estimation than did any other method (R2 = 0.78 compared with R2 = 0.52 to 0.63). These effects were shown under both simultaneous and outpatient conditions. No side effects due to cimetidine occurred.

CONCLUSIONS

In patients with lupus nephritis, the cimetidine-aided CCr offers a compromise between the precise and accurate but expensive and inconvenient research techniques (inulin, iothalamate, or DTPA clearances) and the grossly inaccurate and imprecise but convenient technique (CCr) for determining GFR.

Serial assessment of glomerular filtration rate in lupus nephropathy

In patients with lupus nephropathy (LN), previous studies have shown that creatinine clearance (CCr) overestimates true glomerular filtration rate as measured by inulin clearance (CIn), and that among patients the degree of overestimation is highly variable. We sought to determine whether the discrepancy between CCr and CIn remains constant over time (months, years) in each individual patient, and therefore whether serial measurements of CCr reliably reflect the direction and magnitude of change in CIn. Twenty-five patients with LN underwent simultaneous determinations of CCr and CIn performed two to four (mean 3.3) times over three years. In a given patient, it was found that the ratio of CCr/CIn changed substantially over time (mean SD 0.16 with 95% confidence interval of 0.12 to 0.20). Thus, in about 32% of cases the ratio of CCr/CIn will vary more than +/- 16% from a previously measured value of CCr/CIn. Patients with both high and low values of CIn showed similar variability in CCR/CIn over time. Variability in CCr/CIn was found regardless of whether CIn was increasing, decreasing, or constant over time. In nearly one-half of all measurements of CCr, the corresponding change in CIn was directionally discordant. Iothalamate and technetium-DTPA renal clearances correlated highly with CIn (R2 = 0.99). We conclude that the discrepancy between CCr and CIn can vary greatly over time in an individual patient. Consequently, serial CCr does not accurately measure the direction or magnitude of change in glomerular filtration rate in lupus nephropathy.

Mononeuritis multiplex: the yield of evaluations for occult rheumatic diseases

We identified 35 patients who had electrodiagnostic evidence of mononeuritis multiplex and did not have diabetes or multiple nerve compressions. Their charts were reviewed to determine the etiologies of the mononeuritis multiplex and to determine how often the laboratory examination revealed a rheumatic disease in patients whose initial history and physical examination did not suggest that a rheumatic disease was present. In 11/35 (31%; CI = 17-49) a disorder capable of causing mononeuritis multiplex was diagnosed before the symptoms of mononeuritis multiplex began. Ten had a rheumatic disease; 1 had lymphoma. Nine of the other patients were suspected, on the basis of the history and physical examination, of having new onset of a rheumatic disease. Subsequent laboratory evaluation showed that 5/9 (56%; CI = 21-86) had a rheumatic disease, and 4/9 (44%; CI = 14-79) were unknowns. In 15/35 (43%; CI = 26-61) patients with mononeuritis multiplex, no rheumatic disease was suspected on the basis of the initial history and physical examination. The subsequent laboratory examination revealed an underlying rheumatic disease in 0/15 (0%; CI = 0-18). Mean clinical follow-up of 16 +/- 16 months in the patients with mononeuritis multiplex of unknown cause also failed to identify a rheumatic disease. Overall 19/35 (54%; CI = 37-71) did not have a rheumatic disease or any other known cause. Of the 14 patients with mononeuritis multiplex associated with a rheumatic disease, 5/14 (36%; CI = 13-15) had systemic lupus erythematosus; an additional patient had both lupus and the CREST syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Randomized, double-blind, placebo-controlled study of the treatment of the painful shoulder

The effect of triamcinolone subacromial bursa injection versus naproxen therapy was compared in a randomized, double-blind, placebo-controlled study of 100 patients who had painful shoulders. Outcome was compared using degree of active abduction, pain, limitation of function, and a clinical index that combined equally weighted measures of all of these. In a time-adjusted analysis, triamcinolone was superior to placebo in all clinical variables. Naproxen was superior to placebo in all variables except pain. Triamcinolone was superior to naproxen in the relief of pain (P = 0.04) and the clinical index (P = 0.04). Multiple linear regression analysis showed that naproxen and triamcinolone treatment accounted for only 16% of the variation in outcome, compared with 44% accounted for by the clinical index prior to treatment. Thus, patients with a poor pretreatment clinical index (those with the most room for improvement) were least likely to improve. We conclude that both triamcinolone (P = 0.00005) and naproxen (P = 0.02) are superior to placebo in the treatment of the painful shoulder.

Fatal infections in systemic lupus erythematosus: the role of opportunistic organisms

The causes of death were examined in patients with systemic lupus erythematosus (SLE) who were cared for at the University of California, San Francisco and who died after 1969. Of the 44 deaths analyzed, 33 patients had autopsies. Infections were common and often determined to be the cause of death. Overall, infections were present in 55 percent (22/44), and judged to be a cause of death in 30 percent (13/44) of all deaths. The infections could be divided into 2 groups: those due to common bacterial organisms and those due to opportunistic infections. These two types of infections occurred with similar frequency. When compared to common bacterial infections, however, the opportunistic infections were more likely to be first diagnosed at autopsy (p = .001). In only 3 of the 15 patients with an opportunistic infection was the diagnosis made antemortem. Failure to diagnose an opportunistic infection early occurred when the infection simulated active SLE, and when the possibility of an opportunistic infection was not aggressively investigated. The most common opportunistic infections were Candida albicans and Pneumocystis carinii. The most common site of opportunistic infection was the lung. Seventeen patients had 27 common bacterial infections, chiefly sepsis from Staphylococcus aureus and aerobic gram-negative organisms. Eight patients had both a common bacterial and an opportunistic infection. Stepwise linear regression analysis showed that death from infection correlated most strongly with prednisone and cytotoxic drug use in the 3 months before final admission. No measure of lupus activity was found to correlate with death from infection, except that hypocomplementemia correlated with death from bacterial infections.(ABSTRACT TRUNCATED AT 250 WORDS)

Antinuclear antibody, lupus anticoagulant, and anticardiolipin antibody in women with idiopathic habitual abortion. A controlled, prospective study of forty-four women

In a controlled, prospective study of 44 consecutive women with idiopathic habitual abortion, only 5% had symptoms of rheumatic disease. Patients did not differ from control subjects in the frequency of positive results on tests for antinuclear antibody or anti-double-stranded DNA. Levels of C3 and C4 were higher in the habitual aborters. No patients had anti-Ro. The antiphospholipid antibody results were analyzed using 2 methods: the frequency of antiphospholipid antibodies was 9% by lupus anticoagulant using the Russell viper venom time (95% confidence interval 22-2.5) and 11% by anticardiolipin antibody assay (95% confidence interval 25-3.7), which was not significantly different from that in control subjects. However, the mean levels in the aborters (although within the normal range) were significantly higher than those in control subjects for anti-double-stranded DNA (P = 0.004), lupus anticoagulant (by Russell viper venom time; P = 0.05), and anticardiolipin antibody (P = 0.0007), when examined by multiple linear regression analysis corrected for age and concurrent pregnancy. Of the 3 patients with antiphospholipid antibodies and subsequent successful pregnancies, only 1 was treated with prednisone and aspirin. We conclude that, in the majority of women, subclinical lupus, anti-Ro, the lupus anticoagulant, and anticardiolipin antibodies are not associated with idiopathic habitual abortion.

The frequency of lupus anticoagulant in systemic lupus erythematosus. A study of sixty consecutive patients by activated partial thromboplastin time, Russell viper venom time, and anticardiolipin antibody level

Recent reviews have suggested a higher frequency of the lupus anticoagulant or related antiphospholipid antibodies in patients with systemic lupus erythematosus (21% to 65%) than was found in earlier studies (6% to 18%). In our study of 60 consecutive patients, we found the frequency of the lupus anticoagulant by Russell viper venom time was 6.7% (95% confidence interval, 16.2 to 1.8) and by anticardiolipin antibody assay was 25% (95% Cl, 37.0 to 15.7), compared with 0% (p = not significant) and 2.5% (p = 0.002), respectively, in the normal control population. The Russell viper venom time (p = 0.0001 by t-test) and anticardiolipin antibody levels (p = 0.01) were significantly associated with presumed thrombotic events (stroke, deep venous thrombosis, and digital gangrene). No association with miscarriage or pulmonary hypertension was detected. The Russell viper venom time was more specific than the anticardiolipin antibody level in the prediction of past presumed thrombotic events, miscarriage, or pulmonary hypertension (100% compared with 84%, p = 0.01).

Clinical response to regional intravenous guanethidine in patients with rheumatoid arthritis

A novel therapy for rheumatoid arthritis, regional sympathetic blockade using guanethidine, was investigated in 24 patients with active disease. In a randomized double blind short-term (14 days) study, we evaluated the effect of therapy on subjective responses, change in pain, stiffness, and morning stiffness and no objective responses, change in pinch strength, grip strength, and joint tenderness. Compared to placebo, guanethidine produced a decrease in pain (p less than 0.025) and an increase in pinch strength (less than 0.025) over the 2-week duration of the study. The therapeutic effect of guanethidine may be mediated by an interruption of the proinflammatory effects of the sympathetic nervous system.

Recognition of information in renal biopsies of patients with lupus nephritis

To evaluate the informational value of renal biopsy in nephritis of systemic lupus erythematosus, we selected the records of 30 patients who had a renal biopsy done and also had a known clinical outcome. Detailed case histories were prepared, and three distinct randomly chosen cases were given to 197 academic rheumatologists. The rheumatologists estimated the probability of future clinical events (worsened serum creatinine, worsened urine protein, renal death, and aggressive therapy) at 3 and 12 months after the biopsy. Biopsy results were given in detail, and probability estimates were made of the same clinical events using the additional information. The accuracy of each probability estimate was measured using a scoring function that depends on the estimates and the actual outcomes. Knowledge of the renal biopsy failed to improve predictive accuracy scores of estimates of future serum creatinine levels, urine protein levels, and renal death at 3 and 12 months (p less than 0.0001), and for estimates of the probability of the use of aggressive therapy at 12 months (p less than 0.007). The renal biopsy information improved only the accuracy of predictions concerning the use of aggressive therapy at 3 months (p less than or equal to 0.0003). Knowledge of the renal biopsy results failed to add important prognostic information about the future course of treated lupus nephritis to information already obtained from history, physical examination, and laboratory tests.

The information content from renal biopsy in systemic lupus erythematosus

We analyzed data for the 12-month period after renal biopsy was done in 130 patients with systemic lupus erythematosus to examine whether renal biopsy provides useful information on the nephritis of systemic lupus erythematosus beyond that clinically available. A stepwise linear regression analysis was used to construct a linear before biopsy model that predicted the change in renal function 12 months after biopsy. The model included serum creatinine, patient age, 24-hour urine protein, a laboratory index of renal activity, antibodies to DNA, urinalysis protein, change in inverse creatinine from 6 weeks before biopsy, and urine light chain protein, and had a squared multiple correlation coefficient (R2) of 0.246. Four prospectively chosen renal biopsy variables (glomerular cell counts, percent of sclerotic glomeruli, percent of glomeruli with crescents, and interstitial fibrosis) resulted in a 0.079 improvement in R2 (p less than or equal to 0.012). Both the percent glomerular sclerosis (p less than or equal to 0.0032) and subendothelial deposits shown by electron microscopy (p less than or equal to 0.0026) added significantly to the predictive power of the before biopsy model. Histologic classification did not add significantly to the before biopsy model. The renal biopsy information increased the power of a linear regression model to predict the effect of 12 months of treatment of active lupus nephritis.