Transition from minimal change disease to focal segmental glomerulosclerosis related to occupational exposure: A case report

BACKGROUND: Although minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS) have been described as two separate forms of nephrotic syndrome (NS), they are not completely independent. We report a case of a patient transitioning from MCD to FSGS, review the literature, and explore the relationship between the two diseases. CASE SUMMARY: A 42-year-old male welder, presenting with lower extremity edema and elevated serum creatinine, was diagnosed with NS and end-stage kidney disease (ESKD) based on laboratory test results. The patient had undergone a kidney biopsy for NS 20 years previously, which indicated MCD, and a second recent kidney biopsy suggested FSGS. The patient was an electric welder with excessive levels of cadmium and lead in his blood. Consequently, we suspect that his aggravated pathology and occurrence of ESKD were related to metal nephrotoxicity. The patient eventually received kidney replacement therapy and quit his job which involved long-term exposure to metals. During the 1-year follow-up period, the patient was negative for metal elements in the blood and urine and recovered partial kidney function. CONCLUSION: MCD and FSGS may be different stages of the same disease. The transition from MCD to FSGS in this case indicates disease progression, which may be related to excessive metal contaminants caused by the patient’s occupation.