Abstract
Background: Differential diagnosis between primary focal segmental glomerulosclerosis
(FSGS) and minimal change disease (MCD) is sometimes difficult as nephrotic syndrome
is the main clinical symptom in both diseases.
Objectives: This study has attempted to evaluate the urinary excretion of Th1 and Th2
cytokines as potential biomarkers in distinguishing the two types of nephrotic syndrome,
and predicting outcome of renal function.
Patients and Methods: Thirty-six patients with FSGS (M/F 22/14, Age; 41.9 ± 17 years,
SCr=1.7 ± 0.8 mg/dL, UProt=4.7 ± 5.5 g/24 h), and 21 with MCD (M/F 5/16, Age;
41.4 ± 15 years, SCr = 1 ± 0.4 mg/dL, UProt = 7.9 ± 9.3 g/24 h) were included in the study.
Τh1 (IL-2, IL-12, GM-CSF, INF-γ, TNF-α) and Th2 cytokines (IL-4, IL-5, IL-10, IL-13)
were measured by multiple cytokine assay, Luminex technology, in first morning urinary
samples collected at the day of renal biopsy.
Results: No significant differences in urinary excretion of all cytokines were found between
FSGS and MCD patients. In FSGS however, IL-12 urinary levels were independent factor
correlated with both global sclerosis (R = 0.5, P = 0.009) and interstitial fibrosis (R = 0.5,
P = 0.02). Th1 cytokines (IL-2 and GM-CSF) were significantly increased in FSGS patients
who did not respond to treatment (P = 0.03 and P = 0.007, respectively). Th2 cytokines
(IL-4, IL-5, IL-10, IL-13) were significantly increased in MCD patients with frequent
relapses (P = 0.05, P = 0.001, P = 0.01, P = 0.03).
Conclusions: Urinary excretion of Th1 and Th2 cytokines cannot discriminate FSGS from
MCD. Th1 cytokines, especially IL-12, IL-2 and GM-CSF, may be involved in pathology
and progression of FSGS, while Th2 cytokines are implicated in frequent relapses of
nephrotic syndrome in MCD.