VICTORIA, B.C. – Some patients with systemic lupus erythematosus may be more likely than others to experience a prolonged remission, new data suggest.
In a study of more than 1,500 patients who had SLE, about 2% achieved a remission lasting at least 5 years on either no medication or only antimalarial drugs, Anjali Papneja reported at the annual meeting of the Canadian Rheumatology Association.
The prolonged remissions lasted on average almost 12 years. Nearly a third of the patients had had a monophasic clinical disease course, characterized by only a single flare, before their remission.
Patients achieving a prolonged remission were more likely to be white, had milder disease, and were less likely to have involvement of certain organ systems and to have received steroids or other immunosuppressive agents prior to remission onset.
"Prolonged remission is an infrequent outcome among SLE patients, but it generally lasts for over a decade, and it is preceded by an atypically monophasic clinical course in a significant minority," Ms. Papneja commented.
"We want to know what makes these patients different, how they can be treated most effectively, and how we can harness this unique and desirable outcome more generally," she added.
An attendee asked what the remission rate was if patients who achieved remission on stable immunosuppressive regimens and/or low-dose prednisone were also included.
The reason for including only those patients who had remitted off all steroids and immunosuppressive agents was to distinguish those whose SLE was in true remission (i.e., those in the cohort), from those whose disease was merely suppressed by the ongoing use of these medications, replied Ms. Papneja, a medical student at the University of Toronto. "But they do remain on antimalarials because in recent decades, it has been found that these patients have cardiovascular protective benefits from antimalarials."
The investigators studied all patients with SLE followed at the university’s Lupus Clinic from July 1970 through May 2011.
Patients were defined as having a prolonged remission if they did not have any clinical disease activity for at least 5 years, had regular clinic visits, and received no immunosuppressive medications or at most antimalarial drugs during the remission.
With a mean duration of follow-up of nearly 22 years, 2.4% of the 1,613 patients studied achieved a prolonged remission, after a mean disease duration of about 9 years. These sustained remissions lasted an average of nearly 12 years.
By type, 44% of the remissions were serologically and clinically quiescent, 28% were serologically active but clinically quiescent, and 28% fluctuated between these types.
In the years leading up to the remission, the majority of patients (71%) had a relapsing-remitting clinical course, but a sizable proportion (29%) had a monophasic course. "It’s worthwhile to study these patients further to determine at what point we can safely define a disease course as being monophasic," Ms. Papneja commented. None of the patients achieving prolonged remission had a chronic active course.
In a case-control comparison, in which each patient who achieved prolonged remission was matched with three who did not, the former were more likely to be white (82% vs. 72%), had a lower SLE Disease Activity Index (SLEDAI-2K) score at their first clinic visit (8 vs. 10.6), and had a lower adjusted mean SLEDAI-2K score in the 3 years leading up to remission (3 vs. 5.9).
The group achieving prolonged remission was also significantly less likely to have skin, pulmonary, and central nervous system involvement, but "we noted that there was no difference in renal involvement between cases and controls," she pointed out. Additionally, they were less likely to have received steroids (58% vs. 80%) and other immunosuppressive agents (24% vs. 47%) prior to remission onset, also seeming to point to milder disease.
A study limitation, Ms. Papneja acknowledged, was that only patients continuing care at the clinic were included, and the clinic’s attrition rate was about 10%. Thus, some patients achieving remission and dropping out of care, or having a flare and seeking treatment elsewhere, may have been lost to follow-up.
Ms. Papneja disclosed that she had no relevant conflicts of interest.