SLE Trend: Predictors of Mortality Risk Change in Lupus

Over the past 20 years, while the demographics of systemic lupus erythematosus (SLE) hospitalizations have not noticeably changed, the comorbidities that lead to hospitalizations and poor outcomes in SLE have changed.

Thrombocytopenia, antiphospholipid syndrome and renal involvement were found to be predictors of poor outcomes in hospitalized patients with SLE, which is different from previous years in which multiple admissions, infection, disease activity, younger age, renal and neuropsychiatric involvement, the extent of disease damage (SLICC score), anemia and thrombocytopenia were associated with the increased risk of mortality, according to researchers writing in the July 12 issue of Lupus.

This highlights “once more, the relevance of the coexistence of antiphospholipid syndrome to SLE morbidity and mortality and hinting at thrombocytopenia playing a role as flare severity marker,” wrote Gerard Espinosa, M.D., P.h.D., of University of Barcelona, and colleagues.

This was a retrospective analysis of 814 SLE hospitalizations of 339 patients hospitalized for more than 48 hours over a 20-year period (1995-2015). Researchers identified the causes of hospitalizations and factors associated with hospitalizations, readmissions, admission to intensive care units and mortality.

“The demographics and characteristics of SLE hospitalizations in the scrutinized sample have not markedly varied over the past 20 years, with no significant modification in the causes of admission across the 20-year span except for a decrease in hospitalizations due to musculoskeletal causes and thrombotic events,” the authors wrote.

“Therapy with antimalarials displayed a protective effect regarding hospitalization due to infectious causes, and renal involvement, thrombocytopenia and associated [antiphospholipid syndrome] featured as predictors of poorer hospitalization outcomes,” they added.

THE FINDINGS

The average hospital stay was six days due to flares in 40.2 percent of cases, infection in 19.2 percent of cases (primarily respiratory infections, followed by gastrointestinal and urinary infections), thrombotic events in 5.4 percent of cases. 8.8 percent of admission were for diagnostic procedures, largely due to assess kidney performance.

Longer disease duration and more severe damage were associated with admission due to infection. Of note, antimalarial drugs showed a protective effect regarding admission due to infection. Meanwhile, therapy with oral anticoagulants was associated with admission due to thrombosis.

Antiphospholipid syndrome was a predicting factor for the 32 (3.9%) patients who required admission to an intensive care unit (ICU). The main causes of ICU admission were flare, present in 12 patients, followed by infection in nine patients and catastrophic antiphospholipid syndrome in three patients.

Thrombocytopenia and renal involvement were predicting factors for 47 (5.8%) patients who had a hospital readmission at 30 days. Of the readmissions, 22 were due to systemic lupus erythematosus flare, while the other causes of readmission were infection in nine, diagnostic procedures in seven and neurological causes in four patients.

Eight patients who were hospitalized died during the study. The main cause of mortality was catastrophic antiphospholipid syndrome in four patients followed by infection in three. Antiphospholipid syndrome and thrombocytopenia were associated with mortality.

There was no substantial variation in patients’ demographics or causes of admission during the 20-year period, except for a reduction in admissions due to thrombotic causes, which fell from 8.4% in the 1995–1999 period to 3.5% in the 2010–2015 period, and musculoskeletal causes, which dropped 5.8% to 2.5% in the respective periods.

Throughout the study period, no significant differences were found in the distribution of gender, age, Systemic Lupus Erythematosus Disease Activity Index (SLEDAI) or SLICC at hospital admission.

There was a decrease in articular and mucocutaneous symptoms at admission, from 17.5 percent of patients in both cases in the 1995–1999 period to 8.1 and 7.1 percent in the 2010–2015 period, respectively.

Regarding immunosuppressive treatment, an increase in the use of mycophenolate mofetil and lower doses of glucocorticoids were noted in the latter part of the study. Specifically, no patients were prescribed mycophenolate mofetil from 1995–1999 and 28.3% were prescribed this therapy from 2010–2015. Meanwhile, a decrease in cyclophosphamide use was evident, at 11% and 2% in the respective periods.

TAKE-HOME POINTS

Over the past 20 years, the demographics of systemic lupus erythematosus hospitalizations have not noticeably changed, except for a decrease in hospitalizations due to musculoskeletacauses and thrombotic events.

Cyclophosphamide therapy is associated with hospital admission due to infection, but antimalarial drugs may be protective.

Disease flare and infection are the main causes of hospital admission of patients with systemic lupus erythematosus.

Finally, thrombocytopenia, antiphospholipid syndrome and renal involvement are predicting factors for poor outcome in patients with systemic lupus erythematosus who are hospitalized.

REFERENCE:
Rosa, G.P.D., Ortega, M.F., Teixeira, A., et al. “Causes and factors related to hospitalizations in patients with systemic lupus erythematosus: analysis of a 20-year period (1995–2015) from a single referral centre in Catalonia.” Lupus. July 12, 2019. DOI: 10.1177/0961203319861685