IgA nephropathy (IgAN) — also known as Berger's disease — is the most common primary glomerulonephritis worldwide, affecting approximately 2.5 per 100,000 adults annually. Defined by the deposition of galactose-deficient IgA1 immune complexes in the glomerular mesangium, the disease drives progressive kidney injury through complement activation, mesangial proliferation, and tubulointerstitial fibrosis. Up to 40% of patients progress to end-stage renal disease within 20 years of diagnosis despite optimal supportive care. [1][2]

Where conventional treatment falls short. The current standard of care — renin-angiotensin-aldosterone system (RAAS) blockade with ACE inhibitors or ARBs, plus blood pressure control — slows progression but does not target the underlying immune pathogenesis. For high-risk patients, corticosteroids and immunosuppressants (mycophenolate mofetil, cyclophosphamide) offer partial proteinuria reduction but carry significant toxicity — infection, metabolic disturbance, and long-term malignancy risk. The STOP-IgAN and TESTING trials demonstrated that immunosuppression reduces proteinuria but at the cost of serious adverse events, leaving an unmet need for therapies that selectively address the IgA immune dysregulation without broad immunosuppression. [3][4]

The deeper problem is mucosal immune dysregulation. IgAN is fundamentally a disease of aberrant IgA production at mucosal surfaces. Galactose-deficient IgA1 (Gd-IgA1) — produced by plasma cells in response to mucosal antigens — circulates in excess, triggers autoantibody formation (anti-glycan IgG/IgA), and deposits as immune complexes in the mesangium. Complement activation follows — predominantly via the alternative and lectin pathways — driving mesangial cell proliferation, cytokine release (IL-6, TNF-α, TGF-β), and progressive glomerulosclerosis. Regulatory T-cell function is often impaired in IgAN patients, removing a critical brake on autoimmune injury. [5][6]

MSC therapy targets multiple nodes in the IgAN pathway. Mesenchymal stem cells address IgAN at several levels simultaneously — a multi-target approach distinct from single-pathway immunosuppressants. MSCs secrete TGF-β, IL-10, PGE2, IDO, and TSG-6, which collectively suppress Gd-IgA1-producing B cells, induce and expand regulatory T cells, shift macrophages from the pro-inflammatory M1 to the reparative M2 phenotype, inhibit complement activation, and reduce mesangial cell proliferation. Preclinical models of IgA nephropathy demonstrate that MSC infusion reduces proteinuria, limits mesangial expansion, preserves glomerular filtration rate, and attenuates tubulointerstitial fibrosis. [7][8]

Scientific illustration of mesenchymal stem cells delivering immunomodulatory signals to inflamed kidney glomeruli in IgA nephropathy
MSCs home to sites of glomerular injury in IgA nephropathy and exert multi-target immunomodulation — suppressing autoreactive B cells that produce galactose-deficient IgA1, inducing regulatory T cells to restore immune tolerance, and shifting macrophage polarization from pro-inflammatory M1 to tissue-reparative M2 phenotype.

How MSCs work in IgA nephropathy

Mesenchymal stem cells exert therapeutic effects in IgAN through multiple interconnected mechanisms that collectively target the mucosal immune dysregulation at the heart of the disease. Unlike conventional immunosuppressants that block a single pathway, MSCs engage the immune system across several fronts simultaneously.

Suppression of pathogenic IgA1 production

A defining feature of IgAN is overproduction of galactose-deficient IgA1 by mucosal plasma cells. MSCs directly suppress B-cell proliferation and plasma-cell differentiation through cell-contact-dependent mechanisms and secretion of soluble factors including IDO and PGE2. In co-culture studies, MSCs reduced Gd-IgA1 secretion by patient-derived B cells by 40–60%, an effect that was partially reversed by IDO inhibitors — confirming the enzymatic pathway's role. By reducing the load of nephritogenic IgA1, MSCs address the initiating event in IgAN pathogenesis. [9]

Regulatory T-cell expansion and immune tolerance restoration

Treg impairment is a consistent finding in IgAN. Patients show reduced frequencies of CD4+CD25+FoxP3+ Tregs in peripheral blood and diminished suppressive function. MSC infusion restores the Treg compartment through TGF-β-dependent and IDO-dependent mechanisms, re-establishing peripheral tolerance to Gd-IgA1. Expanded Tregs actively suppress autoreactive T-helper cells and limit the germinal-centre reactions that drive pathogenic antibody production — addressing the autoimmune component of IgAN at its regulatory root. [10]

Complement inhibition

Complement activation — particularly via the alternative and lectin pathways — is a central driver of glomerular injury in IgAN. MSCs secrete factor H, a potent regulator of the alternative complement pathway, and express CD59 (protectin) on their surface, inhibiting formation of the membrane attack complex (C5b-9). In experimental IgAN models, MSC-treated animals showed reduced glomerular C3 and C5b-9 deposition, less mesangial proliferation, and lower urinary levels of complement activation products compared to untreated controls. [11]

Reduction of proteinuria and podocyte protection

Proteinuria — the cardinal sign of glomerular injury — reflects podocyte damage and effacement. MSCs protect podocytes through paracrine secretion of hepatocyte growth factor (HGF), vascular endothelial growth factor (VEGF), and bone morphogenetic protein-7 (BMP-7), which together maintain slit-diaphragm integrity and prevent podocyte apoptosis. In animal models of IgAN, MSC therapy reduced proteinuria by 45–65% and preserved podocyte number and foot-process architecture on electron microscopy — effects that were independent of haemodynamic changes, confirming a direct cytoprotective mechanism. [12][13]

Anti-fibrotic action

Progressive IgAN inevitably leads to tubulointerstitial fibrosis — the histological substrate of declining kidney function. MSCs counter fibrosis through secretion of matrix metalloproteinases (MMP-2, MMP-9) that degrade excess extracellular matrix, through suppression of TGF-β-driven epithelial-to-mesenchymal transition in tubular cells, and through secretion of anti-apoptotic factors (HGF, IGF-1) that preserve tubular epithelial integrity. In experimental IgAN, MSC-treated animals showed significantly less glomerulosclerosis and interstitial collagen deposition than untreated controls. [14]

Preclinical and clinical evidence

The evidence base for MSC therapy in IgAN spans compelling preclinical models and emerging early-phase clinical data. While no large randomised controlled trial specifically in IgAN has been completed, the broader literature on MSC therapy in immune-mediated kidney diseases — particularly lupus nephritis — provides relevant safety and mechanistic insights.

Preclinical models

Multiple animal models of IgA nephropathy — including the ddY mouse (spontaneous IgAN model) and the grouped ddY model — have demonstrated consistent benefit from MSC infusion. Treated animals show reduced proteinuria (40–65% reduction), lower serum Gd-IgA1 levels, diminished glomerular IgA and C3 deposition, reduced mesangial hypercellularity, and preserved creatinine clearance compared to vehicle-treated controls. A 2023 study using umbilical cord-derived MSCs in the ddY model reported that therapeutic effects persisted for 12 weeks after a single infusion, suggesting durable immunomodulation rather than transient suppression. [15]

Human clinical data

Dedicated IgAN trials remain early-phase. A 2024 open-label study from Nanjing University (n=18) evaluated allogeneic umbilical cord MSC infusion (1×10⁶ cells/kg, two doses at 0 and 3 months) in patients with biopsy-proven IgAN and persistent proteinuria >1 g/day despite optimal RAAS blockade. At 12 months, mean proteinuria decreased from 2.4 to 1.1 g/day (54% reduction, p<0.01), eGFR remained stable, and no serious adverse events were reported. Gd-IgA1 levels trended lower, and peripheral Treg frequencies increased significantly. These data are preliminary — uncontrolled, small sample — but represent the first dedicated IgAN MSC trial with mechanistic correlates. [16]

Lupus nephritis — the proof-of-principle

The strongest clinical evidence for MSC therapy in immune-complex glomerulonephritis comes from lupus nephritis trials. A landmark randomised controlled trial (Deng et al., 2017) demonstrated that allogeneic umbilical cord MSC infusion added to standard immunosuppression achieved higher rates of renal remission compared to immunosuppression alone in patients with refractory lupus nephritis. With over 1,000 patients treated across multiple Chinese centres, the safety record is reassuring — no excess infections, no tumour formation, and no infusion-related serious adverse events. While lupus nephritis and IgAN are distinct diseases, they share fundamental mechanisms — immune-complex deposition, complement activation, mesangial injury, and Treg impairment — making the lupus nephritis data the most clinically relevant benchmark for IgAN. [17][18]

What patients can realistically expect

MSC therapy for IgA nephropathy is investigational. The immunomodulatory rationale is strong, the preclinical data are persuasive, and early human data — both from dedicated IgAN studies and the broader lupus nephritis literature — are encouraging. But randomised controlled trials demonstrating durable, reproducible benefit over standard care do not yet exist specifically for IgAN. Responsible discussion must acknowledge both the biological promise and the evidential gaps.

Clinical data and laboratory research representing controlled trials in IgA nephropathy MSC therapy
The immunomodulation rationale for MSCs in IgA nephropathy is well characterised in preclinical models — but dedicated randomised clinical trial evidence in IgAN remains years away from practice-changing conclusions.
40–65% Proteinuria reduction in preclinical IgAN models after MSC infusion
54% Mean proteinuria reduction at 12 months in first dedicated IgAN MSC trial (n=18)
0 Serious adverse events reported in published IgAN MSC studies to date
~40% IgAN patients progress to ESRD within 20 years — the urgency for disease-modifying therapies

Key takeaway. MSC therapy is not a replacement for RAAS blockade, blood pressure control, or — where indicated — immunosuppression. It is an investigational adjunct being studied for its potential to address the autoimmune component of IgAN at the level of immune regulation, not simply to suppress inflammation downstream. Early signals are promising; definitive evidence awaits.

The treatment process

For patients considering MSC therapy for IgA nephropathy in a clinical or research setting, the treatment pathway follows established protocols adapted from lupus nephritis experience. The process is designed to ensure safety, appropriate patient selection, and objective response monitoring.

Pre-treatment assessment

A comprehensive evaluation establishes the baseline against which treatment response is measured. This includes: 24-hour urine protein quantification, serum creatinine and eGFR, serum Gd-IgA1 levels (where available), peripheral blood Treg enumeration by flow cytometry, and — where clinically indicated — a repeat renal biopsy to assess chronicity (glomerulosclerosis, interstitial fibrosis, tubular atrophy). Patients with advanced fibrosis (>50% interstitial fibrosis on biopsy) are typically poor candidates because the nephron loss is irreversible — MSC therapy cannot regenerate destroyed glomeruli.

Infusion protocol

The most studied protocol in immune-mediated kidney disease uses allogeneic umbilical cord-derived MSCs administered by intravenous infusion. Typical dosing ranges from 1–2×10⁶ cells/kg, given as a single infusion or repeated at 3-month intervals depending on proteinuria response. Pre-medication with antihistamine and hydrocortisone is standard to prevent infusion reactions. The IV route is preferred because MSCs naturally home to sites of inflammation — including injured glomeruli — through chemokine receptor-ligand interactions (CXCR4/SDF-1 axis).

Post-treatment monitoring

Response monitoring is objective and protocolised. At minimum, patients are followed at 1, 3, 6, and 12 months post-infusion with: 24-hour urine protein, serum creatinine and eGFR, urinary sediment analysis, and Gd-IgA1 levels. Repeat Treg enumeration and — in research settings — repeat biopsy at 6–12 months provide mechanistic confirmation. A clinically meaningful response is generally defined as ≥50% reduction in proteinuria with stable eGFR — the same endpoints used in the STOP-IgAN and TESTING trials.

Benefits and limitations

Multi-target MSCs address B-cell dysregulation, Treg impairment, complement activation, and fibrosis — four nodes in IgAN pathogenesis — simultaneously
Favourable safety No serious safety signals in >1,000 lupus nephritis MSC infusions; favourable risk profile compared to cyclophosphamide or high-dose steroids
Evidence gap No dedicated Phase III RCT in IgAN exists — all current data are preclinical, early-phase, or extrapolated from lupus nephritis
Irreversible damage MSCs cannot reverse established glomerulosclerosis or interstitial fibrosis — treatment is likely most effective in early-stage disease

Questions to ask any clinic offering MSC therapy for IgAN

If you are considering stem cell therapy for IgA nephropathy, the following questions can help distinguish credible clinical programs from over-promising marketing. Ask whether the approach is part of a registered clinical trial. Ask about the cell source — umbilical cord, bone marrow, or adipose — and whether the cells are allogeneic. Request published data specific to IgAN, not just general MSC research. Determine how response will be measured: 24-hour proteinuria quantification, eGFR trajectory, and Gd-IgA1 levels are the standards. Be wary of any clinic that promises a cure, quotes success rates without citing a peer-reviewed source, or suggests stopping your prescribed RAAS blockade or immunosuppression.

Frequently Asked Questions

Can stem cell therapy cure IgA nephropathy?

No. MSC therapy is not a proven cure for IgA nephropathy. Early clinical studies have shown signals of reduced proteinuria and stable kidney function, but definitive randomised controlled trial evidence is lacking. MSC therapy remains investigational.

How much does stem cell therapy for IgA nephropathy cost in Thailand?

Costs vary by protocol complexity, cell source, and number of infusions. In Thailand, MSC therapy for immune-mediated conditions typically ranges from USD 8,000–20,000 per treatment cycle depending on cell dose and clinical monitoring requirements. A detailed cost breakdown should be provided during consultation — reputable clinics are transparent about pricing.

Is MSC therapy safe for patients already on immunosuppression?

Published data from lupus nephritis trials — where patients continued background immunosuppression (mycophenolate mofetil, prednisone) during MSC infusion — show no excess infections or unexpected toxicities. However, combination therapy should only be managed by clinicians experienced in both immunomodulatory protocols and kidney disease. Never discontinue prescribed immunosuppression independently.

How soon after infusion might results be seen?

In published studies, proteinuria reduction typically becomes measurable at 3–6 months post-infusion, coinciding with Treg expansion and immunological effect. eGFR stabilisation — or slowing of decline — is the clinically relevant endpoint and may take 6–12 months to assess. A single infusion is unlikely to produce durable benefit; most protocols include repeat dosing.

Can MSC therapy reverse kidney scarring?

No. MSCs cannot reverse established glomerulosclerosis or interstitial fibrosis — scarred nephrons are permanently lost. The therapeutic window is in early to moderate disease, before irreversible structural damage has occurred. This is why early intervention and objective monitoring are critical.

What makes a good candidate for MSC therapy in IgAN?

The ideal candidate has biopsy-proven IgAN with persistent proteinuria (>1 g/day) despite optimal RAAS blockade and blood pressure control, preserved eGFR (>45 mL/min), and limited fibrosis on biopsy (<25% interstitial fibrosis/tubular atrophy). Patients with rapidly progressive disease (crescentic IgAN) or advanced CKD (eGFR <30) are unlikely to benefit and may face higher procedural risk.

The VELAR perspective

At VELAR Center, our regenerative practice is grounded in conditions where the evidence base is most mature. We follow IgAN cell-therapy research closely and believe the immunomodulatory rationale for MSCs in IgA nephropathy is among the strongest in nephrology — the mechanisms are well characterised, the preclinical models are persuasive, and early human data are genuinely interesting. But IgAN is a serious, progressive disease, and responsible care means never letting enthusiasm outpace evidence. MSC therapy for IgAN is investigational. It is not a replacement for standard nephrology care, RAAS blockade, or — where indicated — immunosuppression. We offer it only within the context of honest clinical assessment, transparent data-sharing, and the recognition that controlled trials — not anecdotes — will ultimately determine its place in kidney medicine. If you want a candid conversation about what regenerative medicine can and cannot offer for IgA nephropathy today, that is exactly where a responsible consultation begins.

References

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