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Systemic lupus erythematosus is an autoimmune disease that may
affect many organs, especially the skin, musculoskeletal, vascular
and renal systems. It occurs predominantly in women of childbearing
age, but also affects people in their sixth decade or older. In these
patients, female predominance is less marked and renal disease less
common.
The natural history of the disease has changed over the past 20-30
years; survival rates have increased from 50% at five years in the
1950s to 80%-90% at 10 years in the 1990s. The explanations for this
improvement include earlier diagnosis, recognition of milder
disease, advances in medical therapy, and better supportive care,
including renal replacement therapy. Despite these advances, the
standardised mortality ratio for lupus remains at 3. Morbidity and
mortality rates are bimodal, with early events related to disease
activity or infection and later events often due to premature
vascular disease such as stroke and myocardial ischaemia.
Currently, minor manifestations of systemic lupus erythematosus
(cutaneous, musculoskeletal, fatigue) are managed with
non-steroidal anti-inflammatory drugs (NSAIDs), antimalarial
drugs (particularly hydroxychloroquine) and low-dose
corticosteroids. The selective COX-2 inhibitors, celecoxib (a
sulfonamide) and rofecoxib, are now available in Australia. With
their lower gastrointestinal toxicity, they represent a
significant advance. Patients with lupus, however, have a high
prevalence of sulfonamide allergy (20% in some studies) and 30%-50%
have antiphospholipid antibodies, which are associated with
arteriovenous thrombosis and miscarriages (the antiphospholipid
syndrome). Case reports of thrombotic events in patients with
antiphospholipid antibodies taking COX-2 inhibitors necessitate
judicious use of these drugs until further data are
available.1
Hydroxychloroquine should no longer be restricted to those with
minor disease. Data from the Canadian Hydroxychloroquine Study
Group suggest that taking hydroxychloroquine causes a reduction in
flares and a lower risk of organ-threatening
dissemination.2 An ability to lower blood
glucose and cholesterol levels, combined with an antiplatelet
effect, makes this drug an attractive therapeutic option for all
patients with lupus. The risk of retinal toxicity with
hydroxychloroquine may have been overstated in the past, and the
Royal College of Ophthalmologists, London, recommends routine
ophthalmic screening in adults only if the dosage of
hydroxychloroquine is greater than 6.5 mg/kg lean body weight per
day, if there is impaired renal or hepatic function, if visual
symptoms develop, or if the duration of therapy extends beyond five
years.3 Patients refractory to
hydroxychloroquine may show improvement with chloroquine,
although with chloroquine the risk of retinal toxicity is greater.
Treatment-resistant cutaneous lupus has been treated with
thalidomide, with improvement in up to 84% of patients.4 However, its use
will remain limited because of the risk of fetal abnormalities and the
high rate of neuropathy.
There is increasing concern about the long term use of steroids,
including low-dose therapy, in patients with lupus. With time,
musculoskeletal damage, including avascular necrosis and
osteoporosis, heads the organ damage list. Petri has shown that
avascular necrosis is strongly associated with the highest
prednisolone dose used and osteoporosis with the cumulative dose.
She has also shown that an increase in prednisolone dose is associated
with an aggravation of cardiovascular risk factors. If the
prednisolone dose is increased by 10 mg, the average weight gain is 2
kg, and increases in serum cholesterol level and mean arterial blood
pressure occur.5
The management of major organ involvement (eg, renal,
neuropsychiatric) necessitates combining steroids and
immunosuppressants such as cyclophosphamide and azathioprine,
and, more recently, cyclosporin A and mycophenolate mofetil.
Intermittent monthly pulses of intravenous cyclophosphamide is the
standard treatment for diffuse proliferative nephritis and results
in a significant improvement in outcome compared with steroid use
alone. The appropriate treatment for other classes of lupus
nephritis has not been subject to the same level of scrutiny, and
uncertainty exists as to what is the optimum management of membranous
nephropathy.
Although successful in the management of lupus nephritis, high-dose
pulse cyclophosphamide (0.75-1.0 g/m
2 monthly) and steroids have
been associated with significant toxicity, including premature
ovarian failure in 55% and infection in 29% of patients.6
Understandably, fertile women are reticent to accept such therapy
and alternatives need to be considered. In retrospective studies, a
short, low-dose cyclophosphamide regimen followed by azathioprine
has been found to be a successful combination, with reduced incidence
of ovarian failure and infection.7 A European prospective
study comparing high- and low-dose cyclophosphamide for treating
lupus nephritis has now completed recruitment; initial short-term
remission rates are comparable in both groups.8 In small series,
mycophenolate mofetil has been found to be effective, including in
some patients who have shown resistance to cyclophosphamide. Chan et
al found mycophenolate to be equal in efficacy to oral
cyclophosphamide in patients with diffuse proliferative lupus
nephritis.9 Long term data (at least five
years' follow-up) will be necessary to determine the incidence of
relapse and complications. Cyclosporin has been shown to reduce
proteinuria in patients with membranous and diffuse proliferative
nephropathy. However, concern continues about nephrotoxicity and
relapse on ceasing to take the drug. Cyclophosphamide combined with
plasmapheresis has not been shown to provide additional benefit
compared with cyclophosphamide alone, and its use is now limited to
patients who develop a thrombotic thrombocytopenic purpura-like
illness or who have very treatment-resistant disease.10
There is growing interest in the use of immunoablation and stem-cell
transplantation in a variety of autoimmune disorders. Autologous
stem-cell grafting is feasible in systemic lupus erythematosus and
anecdotal reports of success exist. The appropriate timing of
stem-cell transplantation, however, remains difficult. Ideally,
transplantation should occur in patients who have shown resistance
to standard therapy, but before they develop significant
irreversible damage. At this stage, the prognostic markers are not
sufficiently refined to allow early identification of patients
likely to fail immunosuppressive therapy.11
Increased understanding of the pathogenesis of systemic lupus
erythematosus has led to the development of numerous novel
therapeutic agents. Several of these are in phase II and phase III
studies and show promise. However, manipulating the immune system is
not without risk, and the expense, particularly of biological
agents, will initially limit availability to those with severe
disease. While we eagerly await the arrival of such agents, the care of
lupus patients in the early years of the 21st century involves
innovative approaches with available agents, as well as recognising
and aggressively treating the risk factors for premature vascular
disease.
Timothy R Godfrey
Rheumatologist, Rheumatology Unit The Alfred and St Vincent's
Hospitals, Melbourne, VIC
Peter F J Ryan
Clinical Associate Professor of Medicine; and Head Rheumatology
Unit, Alfred Health Care Group, Melbourne, VIC
- Gupta S, McCune WJ, Kaplan M, et al. Thrombosis and ischaemia in
patients with systemic lupus erythematosus treated with celecoxib:
a series of two cases. Arthritis Rheum 1999, 9(Suppl): S149.
-
Tsakonas E, Joseph L, Esdaile JM, et al. A long term study of
hydroxychloroquine withdrawal on exacerbations in systemic lupus
erythematosus. The Canadian Hydroxychloroquine Study Group.
Lupus 1998; 7: 80-85.
-
Royal College of Ophthalmologists. Ocular toxicity and
hydroxychloroquine: guidelines for screening. London: RCO, 1998.
-
Ordi-Ros J, Cortes F, Cucurull, Mauri M, et al. Thalidomide in the
treatment of cutaneous lupus refractory to conventional therapy.
J Rheumatol 2000; 27: 1429-1433.
-
Petri M. Hopkins Lupus Cohort 1999 Update. Rheum Dis Clinics
2000; 26: 199-213.
-
Gourley MF, Austin III HA, Scott D, et al. Methylprednisolone and
cyclophosphamide, alone or in combination, in patients with lupus
nephritis. Ann Intern Med 1996; 125: 549-557.
-
Martin-Suarez I, D'Cruz D, Mansoor M, et al. Immunosuppressive
treatment in severe connective tissue diseases: effects of low dose
intravenous cyclophosphamide. Ann Rheum Dis 1997; 56:
481-487.
-
Houssiau F, Vasconcelos C, Abramovicz D, et al. The Euro-Lupus
Nephritis Trial: comparison between a low dose and a high dose
cyclophosphamide regimen. Ann Rheum Dis 1999 (EULAR
abstracts): 116.
-
Chan TM, Li FK, Tang CS, et al. Efficacy of mycophenolate mofetil in
patients with diffuse proliferative lupus nephritis. N Engl J
Med 2000; 343: 1156-1162.
-
Schroeder J, Schwab U, Zeuner R, et al. Plasmapheresis and
subsequent pulse cyclophosphamide in severe SLE: preliminary
results of the LPSG Trial. Arthritis Rheum 1997, 40(Suppl):
S325.
-
Formiga F, Moga I, Pac M, et al. High disease activity at baseline
does not prevent a remission in patients with systemic lupus
erythematosus. Rheumatology 1999; 38: 724-727.
©MJA 2001
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