Hospitalized patients with systemic lupus erythematosus are more likely to arrive at a specialized rheumatology unit because of an infection than because of a disease flare, according to a retrospective cohort study conducted at a tertiary referral center in Egypt. The analysis of 89 adults admitted between May 2022 and May 2023 found that infection accounted for 51.6 percent of admissions, with bacterial pathogens responsible for 84 percent of documented infections. Yet when patients died during hospitalization, cardiovascular complications, particularly ischemic heart disease, were the leading cause, accounting for half of the six deaths recorded in the cohort.
The study, published in Egyptian Rheumatology and Rehabilitation, was carried out at the Rheumatology and Clinical Immunology Unit of a main university hospital, a 40-bed tertiary referral center staffed by specialized rheumatologists, fellows, and nurses. Patients admitted to this unit typically present with severe disease manifestations, active flares requiring intensive management, or complex complications that cannot be managed in general medical wards. The researchers reviewed medical records using a structured data collection form built on REDCap, extracting demographic information, comorbidities, clinical presentations, laboratory parameters, therapeutic interventions, and in-hospital outcomes.
Eligible participants were adults aged 18 years or older with a confirmed diagnosis of systemic lupus erythematosus according to the Systemic Lupus International Collaborating Clinics 2012 classification criteria. Patients were excluded if they had incomplete clinical data or overlapping autoimmune conditions. Referral criteria for admission to the specialized care unit included severe disease flare requiring intensive immunosuppressive therapy, suspected or confirmed lupus nephritis requiring urgent evaluation or dialysis, severe hematological manifestations, serious infections including life-threatening sepsis, and major organ involvement such as neuropsychiatric lupus, severe serositis, pulmonary hemorrhage, myocarditis, pericarditis, or vasculitis.
The demographic profile of the cohort reflected the established epidemiology of the disease. Nearly all patients were female, 97.8 percent, with a female-to-male ratio of 43.5 to 1, and the mean age at admission was 34.96 years, with a range from 18 to 69. Most patients were married, 83.1 percent, while current smoking was reported in only two patients. A positive family history of systemic lupus erythematosus was reported in 7.9 percent of patients, and 11.2 percent had a family history of other rheumatic diseases. Among the 74 female patients with available obstetric history, the mean gravidity was 2.85 and the mean parity was 2.23, and a history of abortion was reported in 33.8 percent.
Review of previous disease manifestations showed that cutaneous involvement was the most frequently documented, affecting 78.7 percent of patients, followed by arthritis in 64.0 percent and anemia in 53.9 percent. Renal involvement was documented in 46.1 percent. Thrombocytopenia was observed in 27.0 percent, serositis in 25.8 percent, constitutional manifestations in 14.6 percent, leukopenia in 13.5 percent, and neurological manifestations in 11.2 percent. Comorbidities were present in 50.6 percent of patients, with hypertension the most common at 37.1 percent, followed by diabetes mellitus at 10.1 percent and hypothyroidism at 9.0 percent. Malignancy and liver cirrhosis were each reported in two patients.
Beyond infection, renal involvement was another major indication for hospitalization, accounting for 43.8 percent of admissions. Hematological abnormalities were also frequent, including thrombocytopenia at 28.0 percent, anemia at 23.6 percent, and leukopenia at 22.4 percent. Other documented causes included arthritis at 18.0 percent, serositis at 11.2 percent, cutaneous manifestations at 10.1 percent, neurological manifestations at 4.5 percent, constitutional symptoms at 4.5 percent, and autoimmune hepatitis at 2.2 percent. Combined causes of admission were documented in 65.16 percent of patients, reflecting the multisystem involvement and clinical complexity of hospitalized patients with the disease.
Among the 46 patients admitted with infection, 92 percent developed the infection before admission, and regular annual influenza vaccination was reported in only 25 percent of these patients. Bacterial infections accounted for 84 percent of documented infections, followed by viral infections at 14 percent and fungal infections at 4 percent. Lower respiratory tract infections were the most frequent source at 46 percent, followed by urinary tract infections at 40 percent and skin infections at 14 percent. The authors attribute the high susceptibility to bacterial infections to immune dysregulation, disease activity, and the use of immunosuppressive therapies, noting that patients are frequently referred to a specialized rheumatology unit after developing severe infections or complex disease manifestations requiring multidisciplinary care.
Disease activity was assessed using the Systemic Lupus Erythematosus Disease Activity Index within 24 hours of admission, and irreversible organ damage was assessed using the SLICC/ACR Damage Index. More than half of the patients, 51.7 percent, experienced a severe flare with a SLEDAI score above 12, which the authors note is higher than previously reported medians. Irreversible damage was noted in 70.8 percent of patients with a SLICC/ACR score of at least 1, and the mean damage score was 1.70, suggesting that although permanent damage was common, the extent varied among patients. Neurological involvement showed the strongest association with increased organ damage, with a median SLICC/ACR Damage Index of 3.5 in patients with neurological manifestations compared with 1.0 in those without, a difference that was statistically significant.
Renal involvement was the only factor significantly associated with the duration of hospital stay in univariable linear regression analysis, with patients without renal involvement having a significantly shorter stay than those with renal involvement. Among the 39 patients with renal involvement described in the renal section, 59.6 percent had lupus nephritis, and of these, 63 percent had class III or IV lupus nephritis. Renal biopsy was performed in approximately 94 percent of the relevant patients, while 21 percent required a limited number of dialysis sessions. Other renal abnormalities were attributed to associated infections or drug-related effects. Serological findings supported active disease, with all 89 patients testing positive for antinuclear antibodies, anti-double-stranded DNA antibodies positive in 82.0 percent, and low complement C3 and C4 levels observed in 67.4 percent and 46.1 percent respectively.
Treatment patterns reflected the acute nature of the admissions. Glucocorticoids were administered to nearly all patients, 98.9 percent, consistent with their central role in acute flare management, although the authors note that long-term use is associated with organ damage and increased infection risk. Immunosuppressants such as mycophenolate mofetil and cyclophosphamide were used selectively and tailored to individual disease manifestations. At discharge, 83 patients, 93.3 percent, had improved clinically with laboratory results allowing outpatient treatment, while 6 patients, 6.7 percent, died during admission. Although infection, constitutional manifestations, neurological involvement, anemia, and thrombocytopenia were more frequent among non-survivors, these differences did not reach statistical significance, likely because of the small number of fatal events. The authors emphasize that comprehensive cardiovascular risk assessment, alongside optimal control of disease activity and prevention of infection, is essential to reduce morbidity and mortality in hospitalized patients with systemic lupus erythematosus.
Subject of Research: Retrospective cohort study of hospital admissions, disease activity, organ damage, and in-hospital mortality in systemic lupus erythematosus patients at a tertiary rheumatology care unit
Article Title: Hospital admissions and disease outcomes in systemic lupus erythematosus: a retrospective study from a tertiary rheumatology care unit
Article References: Soliman, E., Menesy, R., & Abdelkhalek, S. (2026). Hospital admissions and disease outcomes in systemic lupus erythematosus: a retrospective study from a tertiary rheumatology care unit. Egyptian Rheumatology and Rehabilitation, 53(1), Article 90. https://doi.org/10.1186/s43166-026-00459-0
Image Credits: AI Generated
DOI: 10.1186/s43166-026-00459-0
Keywords: systemic lupus erythematosus, hospital admissions, infection, bacterial sepsis, cardiovascular mortality, lupus nephritis, SLEDAI, SLICC/ACR Damage Index, tertiary rheumatology care, retrospective cohort, organ damage, glucocorticoids
News Source: Ophelia Keating. (November 5, 2026). Infections drive most lupus hospitalizations, cardiovascular disease tops deaths. Scienmag.
