Septicaemia is associated with increased disease activity and mortality in systemic lupus erythematosus: a retrospective analysis from Taiwan

Objective This study aimed to investigate how septicaemia, non-septicaemia infection and the disease itself are associated with disease activity and mortality in inpatients with systemic lupus erythematosus (SLE) in Taiwan. Methods We retrospectively reviewed 1115 patients and enrolled 427 with SLE admitted for lupus flare-ups and co-morbidities. Disease activity and infection type/site were recorded and categorized according to the causes of admission and mortality into three categories, of which two were specified as follows: (a) septicaemia admissions, non-septicaemia admissions; and (b) septicaemia mortality, non-septicaemia infection mortality and non-infection mortality. The relationships between lupus flare-ups and mortality in different groups were analysed using an unpaired t-test, Mann-Whitney U-test and logistic regression. Results Septicaemia was the major cause of mortality in SLE inpatients. There were 98 (22.95%) mortality patients among all 427 SLE patients. The septicaemia admissions had higher disease activity (SLE Disease Activity Index 2000 = 13.00 +/- 7.98) than the non-septicaemia admissions (9.77 +/- 5.72; p < 0.01). The mean current SLEDAI score of the septicaemia mortality group (14.91 +/- 8.01) was higher than that of the non-septicaemia infection mortality group (10.05 +/- 5.75; p = 0.02), in spite of the similar mean earlier SLEDAI score. The risk of mortality in the septicaemia mortality group due to previous septicaemia admissions was 13.2 times (odds ratio) higher than in the non-septicaemia infection mortality group and 15.6 times higher than in the non-infection mortality group. Conclusion Septicaemia relates to increased lupus disease activity and is associated with a greater risk of mortality in the SLE patients than other causes of admission. Fewer previous septicaemia admissions decrease the risk of septicaemia mortality.