Lupus (Systemic Lupus Erythematosus or SLE) is a chronic autoimmune disease where the immune system mistakenly attacks healthy tissues and organs, causing widespread inflammation and potential damage to systems like the joints, skin, kidneys, brain, and heart. Infusion therapy delivers powerful medications directly into the bloodstream via an intravenous line. This direct delivery ensures the medication is rapidly available to modulate the overactive immune response. Infusions are typically reserved for patients with moderate to severe disease, especially when symptoms are difficult to control with standard oral or subcutaneous medications.
When Infusion Therapy Becomes Necessary
Rheumatologists prescribe infusion therapy when the disease activity poses a significant threat to organ function. Severe manifestations, such as lupus nephritis (inflammation of the kidneys) or central nervous system involvement, often require the immediate and high concentration of medication that an infusion provides.
Infusions are also introduced when a patient’s condition is deemed refractory, meaning it has not responded adequately to initial or standard treatments. This includes situations where conventional therapies, such as high-dose oral immunosuppressants or corticosteroids, fail to achieve low disease activity or remission. Furthermore, standard oral treatments may cause side effects that are too severe for the patient to tolerate long-term, making an intravenous alternative necessary.
Specific Medications Delivered via Infusion
Medications administered via infusion target specific components of the complex autoimmune process in lupus. One targeted biologic agent is belimumab (Benlysta), a monoclonal antibody. Belimumab works by binding to and neutralizing B-lymphocyte stimulator (BLyS), a protein that helps B cells survive and mature. Blocking BLyS reduces the number of abnormal B cells that produce the autoantibodies responsible for lupus inflammation.
Another common treatment is rituximab, often used for severe or refractory disease, though not specifically approved for lupus. This medication is an antibody that targets the CD20 protein found on the surface of B cells. Binding to CD20 causes the destruction and depletion of these B cells from circulation, reducing the immune cells that drive the autoimmune attack. Since B cells regenerate over time, rituximab infusions are typically given in cycles spaced several months apart.
Cyclophosphamide functions as a broad-spectrum immunosuppressant. This potent agent is particularly used for severe, organ-threatening disease, such as advanced lupus nephritis or serious central nervous system involvement. Cyclophosphamide works by interfering with the DNA of rapidly dividing immune cells, effectively reducing their numbers and dampening the overall immune response. Its use is reserved for aggressive disease flares due to its stronger, less specific effect compared to targeted biologics. A newer biologic, anifrolumab (Saphnelo), targets the type I interferon receptor, which is often overactive in lupus patients, inhibiting a signaling pathway that contributes to the inflammatory state.
The Infusion Session Experience
Infusion treatment takes place in an outpatient center or clinic setting. Patients are often advised to hydrate well beforehand to ease the insertion of the intravenous line. A healthcare professional inserts a small catheter, usually into a vein in the arm or hand, to establish the route for medication delivery.
Before the main medication starts, patients often receive pre-medications (e.g., an antihistamine, acetaminophen, or a corticosteroid) to help prevent acute infusion-related reactions. The duration varies significantly depending on the drug; some, like belimumab, may take about an hour, while others, such as rituximab, can require four to six hours. A registered nurse closely monitors the patient for immediate side effects, such as changes in heart rate, blood pressure, or signs of an allergic reaction.
Once the infusion is complete, the IV line is removed, and the patient is typically monitored for a short period before being cleared to leave. Patients may experience mild fatigue following the treatment and should plan for rest for the remainder of the day.
Evaluating Treatment Response
Since these medications modify the immune system, it often takes several weeks or months before a noticeable improvement in symptoms or a reduction in disease activity occurs. The ultimate goal is to achieve and maintain disease remission, or at least a state of low disease activity, to prevent further organ damage.
Clinicians monitor specific laboratory metrics to evaluate treatment success. These include measuring complement protein levels, which are typically low during active disease, and tracking anti-dsDNA antibodies, which are autoantibodies specific to lupus. Kidney function is also assessed through tests like the urine protein-to-creatinine ratio, especially in patients with lupus nephritis.
Disease activity is formally tracked using standardized tools, such as the SLE Responder Index (SRI) or the BILAG-based Composite Lupus Assessment (BICLA). The frequency of treatments depends on the medication, ranging from a monthly schedule for certain biologics to cycles spaced six months or more apart for cell-depleting therapies.