Focal Segmental Glomerulosclerosis (FSGS) is a kidney disease characterized by scarring in the glomeruli, the tiny filtering units within the kidneys. Each kidney contains approximately one million glomeruli responsible for filtering waste products from the blood while retaining essential nutrients. When FSGS damages these filters, protein can leak into the urine, a condition known as proteinuria. This scarring disrupts the kidney’s ability to function, making treatment a priority to slow progression and preserve remaining kidney function.
Understanding FSGS Treatment Goals
Treatment for FSGS aims to maintain kidney health and improve a patient’s quality of life. A primary objective is to reduce proteinuria, the presence of excessive protein in the urine. Proteinuria indicates kidney damage, and its reduction is associated with better long-term kidney survival.
Treatment also works to preserve kidney function by slowing the rate at which glomeruli become scarred. While damaged glomeruli cannot be repaired, treatment helps prevent further deterioration. Managing symptoms like swelling (edema) is another goal, often achieved through medications that help the body eliminate excess fluid. These strategies strive to prevent or delay progression to kidney failure.
Pharmacological Treatments
Pharmacological treatments for FSGS often involve a multi-pronged approach, utilizing different classes of medications. Corticosteroids, such as prednisone, are frequently a first-line therapy for patients with primary FSGS, particularly those with significant proteinuria. These drugs suppress the immune system and reduce inflammation within the kidneys, with remission rates ranging from 40% to 60%.
For patients who do not respond adequately to corticosteroids or experience unacceptable side effects, other immunosuppressants may be introduced. Calcineurin inhibitors, such as cyclosporine or tacrolimus, are commonly used in steroid-resistant cases. These medications also suppress the immune system, helping to reduce proteinuria and potentially improve kidney function. Mycophenolate mofetil is another immunosuppressive option, sometimes used when corticosteroids or calcineurin inhibitors are not appropriate. Rituximab, a monoclonal antibody that targets B-cells, has shown promise in some patients, including those with recurrent FSGS after kidney transplantation, leading to partial or complete remission.
Beyond immunosuppression, non-immunosuppressive drugs play a supporting role. Angiotensin-converting enzyme (ACE) inhibitors (e.g., enalapril, lisinopril) and angiotensin receptor blockers (ARBs) (e.g., losartan, candesartan, valsartan) are frequently prescribed. These medications control blood pressure, which is often elevated in FSGS, and help reduce protein loss in the urine by decreasing pressure within the kidney’s filtering units. Diuretics, such as furosemide, are used to manage fluid retention and reduce swelling, common symptoms of FSGS.
Supportive Care and Lifestyle Adjustments
Supportive care and lifestyle adjustments are important components of FSGS management, promoting kidney health. Dietary modifications are often recommended to reduce the burden on the kidneys and manage symptoms. This includes limiting sodium intake to around 2 grams per day to help control blood pressure and reduce fluid retention.
Controlled protein intake is also advised, with recommendations falling in the range of 0.8 to 1.3 grams of high biologic value protein per kilogram of body weight daily. While protein is necessary, excessive intake can increase the workload on the kidneys. Maintaining healthy blood pressure is a consistent focus, with a target below 130/80 mmHg, and sometimes even 125/75 mmHg for patients with significant proteinuria.
Managing cholesterol levels is another aspect of supportive care, as individuals with kidney disease often have elevated cholesterol, increasing their risk for cardiovascular complications. Lifestyle changes, including dietary adjustments to limit saturated and trans fats, can help. Regular physical activity also contributes to overall health by helping to control blood pressure, manage weight, and improve cholesterol levels.
Managing Advanced Disease
When FSGS progresses to advanced stages or end-stage kidney disease (ESKD), additional interventions become necessary to sustain life. Kidney replacement therapies are then considered to take over the work of the failing kidneys. Dialysis is one such therapy, which can be either hemodialysis or peritoneal dialysis.
Hemodialysis involves using a machine to filter the blood outside the body, typically performed several times a week. Peritoneal dialysis uses the lining of the abdomen to filter waste products, often done at home. Kidney transplantation is another option, involving the surgical placement of a healthy kidney from a donor into the patient’s body. While FSGS can recur in the transplanted kidney in about 30-50% of cases, it is not considered a reason to avoid transplantation.