The goal of this clinical trial is to verify whether a cell culture system can be used to evaluate the presence of a factor capable of causing proteinuria in the serum of patients with primary podocytopathies. This system will also be used to evaluate the in vitro efficacy of a combined therapy for the treatment of this disorder.

Researchers will compare samples from patients with primary podocytopathies with those obtained from healthy subjects and patients with other renal disorders.

Participants will be asked to visit the clinic at regular intervals for up to 36 months, and to provide blood and urine samples (and a sample of the discarded plasmapheresis effluent in case the procedure is performed).

Inclusion Criteria:

• Signature of informed consent for study participation

• One of the following conditions:

  1. Patients with primary podocytopathies (with a histological diagnosis of FSGS or MCD) showing clinical and/or histological evidence of post-transplant recurrence.
  2. Patients with primary podocytopathies (with a histological diagnosis of FSGS or MCD) without clinical and/or histological evidence of post-transplant recurrence.
  3. Patients with primary podocytopathies in their native kidneys in an active clinical phase of the disease.
  4. Patients with podocytopathies presenting clinical features compatible with a secondary form due to another condition.
  5. Patients with glomerulonephritis other than primary podocytopathies (e.g., IgA nephropathy, systemic lupus erythematosus, membranous nephropathy).
  6. Patients with no history of renal diseases

Exclusion Criteria:

• Subjects affected by primary podocytopathies or other glomerulonephritides in clinical remission or with ESRD (eGFR < 15 ml/min) and/or on renal replacement therapy
• Individuals unable to understand and consent to the study procedures
• Any clinical condition that, according to the investigator's judgment, could compromise patient safety during study participation