# Treatment of Glomerular Diseases: Evidence-Based Immunosuppressive Strategies ## Learning Objectives By the end of this module, you will be able to: 1. **Apply** KDIGO guidelines for first-line therapy in specific glomerular diseases 2. **Understand** mechanisms of action for major immunosuppressive drug classes 3. **Recognize** steroid-resistant presentations and appropriate salvage strategies 4. **Navigate** drug selection for special populations (pregnancy, renal impairment) 5. **Monitor** for treatment response and toxicity ------------------------------------------------------------------------ ## Foundational Principles of Glomerular Disease Treatment ### Universal Supportive Care (All Diseases) **Blood Pressure Control:** - The 2025 AHA/ACC guideline and the ADA Standards of Care use a target of \<130/80 mmHg. - KDIGO 2021 (Blood Pressure in CKD) suggests a target systolic \<120 mmHg when tolerated, using standardized office measurement (grade 2B, driven by the CKD subgroup of SPRINT). It explicitly excludes kidney transplant recipients and patients on dialysis. - Much of the gap is measurement technique rather than disagreement about physiology: KDIGO’s lower number presumes a standardized or unattended reading, which most routine clinic cuffs do not meet. - Use RAAS blockers (ACE inhibitors or ARBs) as foundation **RAAS Blockade (Angiotensin System Inhibition):** - First-line for virtually all glomerular diseases - Reduces proteinuria 30-50% through hemodynamic and anti-inflammatory mechanisms - Provides kidney protection through non-immunologic pathways - Maximize dose to highest tolerated level **Lifestyle Modifications:** - Sodium restriction (\<2 g/day) reduces edema and blood pressure - Protein restriction (0.8 g/kg/day) in CKD, modest reduction in primary GN - Lipid management with statins - Weight loss when overweight **Anticoagulation in Nephrotic Syndrome:** - Risk of venous/arterial thromboembolism elevated - Membranous nephropathy and FSGS highest risk - Screen for clinical indicators; anticoagulate if risk substantial ------------------------------------------------------------------------ ## Disease-Specific Treatment Algorithms ### Minimal Change Disease (MCD) **First-Line Therapy:** - **Corticosteroids (all patients)** - Prednisone 1 mg/kg/day (maximum 80 mg) or 2 mg/kg every other day - Maintain high dose minimum 4 weeks, maximum 16 weeks - Taper slowly over 6+ months after complete remission achieved - **Expected response:** 85-95% complete remission rate **Frequently Relapsing/Steroid-Dependent MCD:** - **Cyclophosphamide** (KDIGO first-line) - Oral 1-2 mg/kg/day for 8-12 weeks - Remission rate 80% with \<10% relapse at 1 year - Alternative: CNI monotherapy often requires long-term therapy - **Calcineurin Inhibitors** - Cyclosporine or tacrolimus as alternative to cyclophosphamide - Remission rates 70-80% - Relapse frequent during tapering - **Mycophenolate Mofetil (MMF)** - Emerging option for patients with cyclophosphamide failure - 1,200 mg/m²/day divided doses - Effective even in cyclophosphamide-refractory disease - **Rituximab** - Anti-B cell antibody - Steroid-sparing benefit in pediatric population - Increasingly used in adults ### Focal Segmental Glomerulosclerosis (FSGS) **Primary FSGS - Initial Treatment:** - **Corticosteroids (first-line)** - Prednisone 1 mg/kg/day (maximum 80 mg) - Duration 8-16 weeks to determine response - 40-50% achieve remission with steroids **Steroid-Resistant FSGS (KDIGO 2021):** - **Calcineurin Inhibitors (first-line)** - **Cyclosporine:** 5-10 mg/kg/day targeting trough 125-175 ng/mL - **Tacrolimus:** 0.1-0.2 mg/kg/day divided doses - **Tacrolimus particularly effective:** 81% complete remission in SRNS - CNI + low-dose steroid reduces corticosteroid exposure - **Mycophenolate Mofetil** - Alternative for CNI-intolerant patients - Complete/partial remission reduction 67% in SRNS - Less effective than CNI monotherapy - **Sirolimus** - mTOR inhibitor - Reduces proteinuria and glomerular pore size in SRNS - Limited experience; reserve for specific scenarios - **Rituximab** - Emerging data for steroid-resistant FSGS - May be particularly effective for certain FSGS subtypes **Secondary FSGS:** - Treat underlying cause (HIV, obesity, remove nephrotoxin) - Immunosuppression generally ineffective - RAAS blockade foundation of therapy ### Membranous Nephropathy **Diagnosis and Risk Stratification:** - **Anti-PLA2R antibody testing:** Positive in 70-80% of primary MN - **Risk categories determine treatment intensity** **Low-Risk Patients:** - Normal eGFR, proteinuria \<3.5 g/dL, albumin \>30 g/L - **Conservative therapy:** RAAS blockade, lipid management - Monitor; 30% achieve spontaneous remission **Moderate-Risk Patients:** - Can receive symptomatic therapy (RAAS blockade, edema control) - OR rituximab OR calcineurin inhibitors **High/Very High-Risk Patients:** - Proteinuria \>4 g/day, declining eGFR, high anti-PLA2R titers - **Require immunosuppressive treatment** **Treatment Options:** - **Rituximab (KDIGO first-line)** - Superior in maintaining remission (60% vs. 20% with cyclophosphamide at 24 months) - Fewer adverse events - Re-treatment if failing to attain immunological remission at 3 months - **Modified Ponticelli Regimen (Cyclophosphamide + Steroids)** - Alternating months of IV methylprednisolone + oral cyclophosphamide - Proven effective over decades - Immunological response faster at 6 months but comparable by 24 months - **Calcineurin Inhibitors** - Cyclosporine 3-5 mg/kg/day targeting trough 125-175 ng/mL - Higher relapse rates compared to other treatments ### IgA Nephropathy **Proteinuria \<0.5 g/day:** - RAAS blockade alone **Proteinuria 0.5-1 g/day:** - RAAS blockade + consider steroids **Proteinuria \>1 g/day Despite RAAS Blockade:** - **TARPEYO (targeted-release budesonide)** indicated - Delivers therapy to Peyer’s patches - 27% proteinuria reduction, 50% eGFR decline reduction **Progressive Disease or High-Risk Features:** - **Sparsentan (dual endothelin/ARB antagonist)** - 49.8% vs. 15.1% proteinuria reduction vs. irbesartan - Indicated for high-risk patients - Mycophenolate mofetil for rapid progression - Cyclophosphamide reserved for rapidly progressive disease ### ANCA-Associated Vasculitis (AAV) **Induction Therapy (Remission Induction):** **Non-Severe Disease:** - Rituximab or mycophenolate mofetil + corticosteroids **Severe/Organ-Threatening Disease:** - Cyclophosphamide or rituximab + high-dose corticosteroids - IV methylprednisolone 0.5-1 g/day × 3 days - Oral prednisone 1 mg/kg/day tapered **Life-Threatening Disease (Pulmonary Hemorrhage):** - Above therapy PLUS plasma exchange (7-14 days) - Cyclophosphamide dosing: IV 15 mg/kg every 2 weeks or daily oral 1.5-2 mg/kg **Avacopan (C5a Receptor Antagonist):** - FDA approved 2021 for severe active ANCA-associated vasculitis - Complement C5a receptor antagonist - Used as adjunctive therapy with standard immunosuppression **Maintenance Therapy (≥18-24 months):** - Azathioprine 2 mg/kg/day OR - Mycophenolate mofetil 1 g twice daily OR - Rituximab 500 mg every 6 months - Low-dose prednisone (goal \<7.5 mg/day) ### Lupus Nephritis **Class I-II:** - Conservative management - Hydroxychloroquine (all patients) **Class III-IV (Proliferative):** **Induction Therapy (3-6 months):** - **Option A (MMF-preferred):** - Mycophenolate mofetil 1-3 g/day - Corticosteroids (tapered to lowest effective dose) - 50-60% remission rate - **Option B (Cyclophosphamide):** - IV 500-1000 mg/m² × 6 pulses monthly - Indicated for crescentic or rapidly progressive disease - Proven effective but more toxicity than MMF - **Belimumab (Anti-BLyS):** - Added to standard induction - First biologic approved for lupus nephritis - **Obinutuzumab (Anti-CD20):** - Potent B-cell depletion - FDA approval pending; shows benefit especially in high-proteinuria patients **Maintenance (≥2-3 years):** - Mycophenolate mofetil or azathioprine - Low-dose prednisone (goal \<7.5 mg/day) **All patients:** - Hydroxychloroquine 200-400 mg daily (reduces flares, mortality benefit) **Class V (Membranous):** - Calcineurin inhibitors or mycophenolate mofetil - Low-dose steroids ### Anti-GBM Disease (Goodpasture Syndrome) **Urgent Treatment (Medical Emergency):** - **Plasma Exchange:** 7-14 days or until anti-GBM antibodies undetectable - Essential for antibody removal - Most effective if initiated before serum Cr \>5.7 mg/dL - **Immunosuppression:** - IV methylprednisolone 1 g daily × 3 days - Oral prednisone 1 mg/kg/day - Cyclophosphamide 2 mg/kg/day (oral) **Prognosis:** 90% patient survival with treatment; renal recovery depends on initial severity ------------------------------------------------------------------------ ## Major Drug Classes: Mechanisms and Monitoring ### Corticosteroids **Mechanism:** - Glucocorticoid receptor-mediated gene transcription - Induces apoptosis through BIM expression - NF-κB inhibition - Anti-inflammatory cytokine effects **Dosing Principles:** - Use lowest effective dose - Taper slowly after remission - Prolonged therapy increases infection risk, osteoporosis **Key Monitoring:** - Blood glucose (hyperglycemia) - Bone density (osteoporosis prevention) - Infection risk - Psychological effects ### Calcineurin Inhibitors (CNI) **Mechanism:** - Bind calcineurin phosphatase - Prevent NFAT dephosphorylation - Block T-cell activation and IL-2 production **Specific Agents:** - **Cyclosporine:** Monitor trough levels (125-175 ng/mL for GN) - **Tacrolimus:** Monitor trough levels (5-10 ng/mL for GN) **Key Advantages:** - Rapid onset of action - Effective for steroid-resistant disease **Key Toxicities:** - Nephrotoxicity (can worsen renal function) - Hypertension - Hyperglycemia - Drug interactions (CYP3A4) - Tremor, gingival hyperplasia (cyclosporine) ### Antiproliferative Agents #### Mycophenolate Mofetil (MMF) **Mechanism:** - Selective IMPDH type II inhibitor - Blocks T and B lymphocyte proliferation - Non-selective mechanism but selective for lymphocytes **Dosing:** - 1-3 g/day divided doses - Dose-dependent effect (more drug, more effect) **Monitoring:** - CBC (lymphopenia may indicate overdosing) - Gastrointestinal tolerance - Pregnancy risk (teratogenic) #### Azathioprine (AZA) **Mechanism:** - Purine antimetabolite - Inhibits DNA synthesis - More general immunosuppression **Monitoring:** - TPMT enzyme activity (genetic polymorphism affects metabolism) - CBC (myelosuppression) - LFTs ### Alkylating Agents #### Cyclophosphamide **Mechanism:** - Nitrogen mustard alkylating agent - Forms DNA crosslinks - Cell cycle arrest and apoptosis **Dosing Variations:** - IV pulse: 500-1,000 mg/m² monthly - Oral daily: 1-2 mg/kg/day **Key Toxicities:** - Myelosuppression - Hemorrhagic cystitis (rare at GN doses) - Secondary malignancies (with prolonged use) - Infertility **Monitoring:** - CBC - Urinalysis (hematuria detection) - Adequate hydration to prevent cystitis ### B-Cell Depleting Agents #### Rituximab (Anti-CD20) **Mechanism:** - Monoclonal antibody targeting CD20 on B cells - Multiple killing mechanisms: CDC, ADCC, ADCP, direct apoptosis **Dosing for GN:** - 375 mg/m² weekly × 4 weeks OR - 1 g × 2 doses 2 weeks apart **Key Advantages:** - Effective for multiple GN types - Good safety profile - Can be used in pregnancy (compatible) **Key Considerations:** - Hypogammaglobulinemia with prolonged B-cell depletion - Infection risk - Progressive multifocal leukoencephalopathy (rare) ### Complement Inhibitors #### Eculizumab (C5 Complement Inhibitor) **Mechanism:** - Binds C5, prevents terminal complement activation - Preserves C5a-mediated immunity **Indications:** - C3 glomerulopathy - Select cases of ANCA vasculitis - Post-infectious GN (limited data) #### Iptacopan (Factor B Inhibitor) **Mechanism:** - Selective alternative pathway inhibition - Preserves classical and lectin pathways **Application:** IgA nephropathy (emerging) ------------------------------------------------------------------------ ## Special Populations: Treatment Modifications ### Pregnancy **General Principles:** - Avoid teratogenic agents: mycophenolate, calcineurin inhibitors (controversial), some biologics - Compatible agents: corticosteroids, azathioprine, rituximab, cyclophosphamide (with caution) - ACE-I/ARB contraindicated; switch at conception ### Renal Impairment **Dose Adjustments:** - Mycophenolate: Reduce in eGFR \<25 - Cyclophosphamide: Reduce in significant renal impairment - CNI: Monitor levels closely, nephrotoxicity concern - Most biologics: No dose adjustment needed ### Infection Risk Populations - Baseline CD4 \<200: Avoid intensive immunosuppression if possible - Prior tuberculosis: Vigilant monitoring during anti-TNF therapy - Hepatitis B: Risk of reactivation with B-cell depletion ------------------------------------------------------------------------ ## Monitoring Treatment Response ### Clinical Response Markers **Complete Remission:** - Proteinuria \<0.3 g/day (or \<300 mg/day) - Normal serum creatinine **Partial Remission:** - ≥50% reduction in proteinuria - Stable or improved serum creatinine **No Response:** - \<50% proteinuria reduction or increasing creatinine ### Laboratory Monitoring Timeline **Baseline (Before Therapy):** - 24-hour urine protein or UPCR - Serum creatinine, BUN, electrolytes - CBC, LFTs - Serologies as indicated **During Induction (First 3-6 months):** - Monthly: Serum creatinine, CBC (if cyclophosphamide/MMF) - 3 months: 24-hour urine protein or UPCR - Drug levels (CNI if used) **Maintenance Phase:** - 3-6 months: Creatinine, urine protein - Quarterly: CBC if on mycophenolate - Annual: Comprehensive metabolic panel, lipids ------------------------------------------------------------------------ ## Practice Questions **Question 1:** A 35-year-old female with MCD relapses 5 times in 12 months. What is the KDIGO-recommended first-line therapy for frequently relapsing MCD? 1. Rituximab 2. Cyclophosphamide 3. Calcineurin inhibitors 4. Higher-dose prednisone **Correct Answer: B** — KDIGO recommends cyclophosphamide for frequently relapsing (≥2 relapses in 6 months) or steroid-dependent MCD. Oral cyclophosphamide 1-2 mg/kg/day for 8-12 weeks achieves 80% remission with \<10% relapse at 1 year. ------------------------------------------------------------------------ **Question 2:** A 28-year-old with Class IV lupus nephritis and activity index 15/24 is steroid-intolerant (severe hyperglycemia, psychosis). Which alternative first-line induction therapy is most appropriate? 1. High-dose IV cyclophosphamide pulses 2. Mycophenolate mofetil monotherapy 3. Calcineurin inhibitor therapy 4. Rituximab monotherapy **Correct Answer: B** — Mycophenolate mofetil is KDIGO first-line alternative for steroid-intolerant patients with proliferative lupus nephritis. MMF 1-3 g/day achieves comparable remission rates to cyclophosphamide with less toxicity. CNI not first-line for Class IV. Cyclophosphamide as alternative if MMF fails. ------------------------------------------------------------------------ **Question 3:** A 52-year-old with IgA nephropathy and 4.2 g/day proteinuria after maximizing ACE inhibitor therapy. Which therapeutic agent directly targets abnormal IgA production? 1. TARPEYO (targeted-release budesonide) 2. Sparsentan 3. Mycophenolate mofetil 4. Corticosteroids **Correct Answer: A** — TARPEYO delivers budesonide specifically to Peyer’s patches in the small intestine, targeting the presumed site of abnormal galactose-deficient IgA production. This mechanism-based approach reduces proteinuria 27% and slows eGFR decline by 50% over 2 years. ------------------------------------------------------------------------ ## Clinical Pearls: Treatment Selection 1. **RAAS blockade foundation** — use ACE-I or ARB for ALL glomerular diseases 2. **MCD: Steroids work** — 85-95% remission rate with appropriate dosing 3. **FSGS: CNI \> steroids** — 81% remission with tacrolimus vs. 50% with steroids 4. **MN: Rituximab preferred** — superior remission maintenance vs. cyclophosphamide 5. **AAV: Rituximab replacing cyclophosphamide** — comparable efficacy, less toxicity 6. **Lupus: MMF first-line** — preferred over cyclophosphamide; steroid-sparing 7. **IgAN: TARPEYO targets source** — mechanism-based therapy addressing pathogenic step 8. **Always use lowest effective dose** — balance efficacy against cumulative toxicity ------------------------------------------------------------------------ ## See Also ### Related Student Handouts - Nephritic and Nephrotic Syndromes - Lupus Nephritis - IgA Nephropathy - FSGS - Vasculitis and Complement-Mediated Diseases - Immunosuppressive Therapy in Nephrology - Kidney Biopsy Essentials ### Clinical Content (01-Clinical-Medicine/Nephrology) - Glomerular Diseases Hub - Essential Renal Laboratory Tests ### Butler-COM Resources - Butler COM - Nephrology Deep Dive ------------------------------------------------------------------------ ## Related Topics - Detailed Supportive Care - Updated Evidence-Based Guidelines - Therapeutic Drug Level Management - Osteoporosis, Infection, Metabolic Complications ------------------------------------------------------------------------ ## Summary Modern treatment of glomerular diseases integrates specific immunosuppressive agents with supportive care to achieve remission while minimizing cumulative toxicity. KDIGO guidelines recommend disease-specific algorithms balancing efficacy and safety. RAAS blockade provides universal renoprotection across all glomerular diseases. Corticosteroids remain highly effective for minimal change disease but steroid-resistant presentations require alternative agents (calcineurin inhibitors, mycophenolate mofetil, rituximab). Modern biologics including belimumab, obinutuzumab, and complement inhibitors expand treatment options and improve outcomes. Understanding mechanisms of action enables rational drug selection and risk stratification for special populations. Close monitoring of clinical and laboratory response guides therapy adjustments, enabling most patients with glomerular disease to achieve remission and preserve long-term kidney function. --- [Website version](https://urinenephrology.org/student-resources/glomerular/glomerular-treatment-student-handout.html) · Markdown synchronized October 3, 2026.