ABSTRACT
IgA nephropathy (IgAN) and focal segmental necrotizing glomerulonephritis (FSNGN) are characterized by proliferation of native glomerular cells and infiltration by inflammatory cells. Several cytokines act as mediators of kidney damage in both diseases. The aim of the present study was to investigate the role of Th1, Th2 and Treg/T17 cytokines in these types of proliferative glomerulonephritis. Simultaneous measurement of Th1 interleukin (IL-2, IL-12, tumor necrosis factor-alpha [TNF-α], interferon-gamma [INF-γ]), Th2 (IL-4, IL-5, IL-6, IL-10, IL-13), Treg/T17 transforming growth factor-beta 1 (TGF-ß1, granulocyte-macrophage colony-stimulating factor [GM-CSF], IL-17) cytokines and C-C chemokines Monocyte chemoattractant protein-1 (MCP-1, macrophage inflammatory protein-1 [MIP-1] ß) was performed in first-morning urine samples, at the day of renal biopsy, using a multiplex cytokine assay. Cytokine concentrations were correlated with histological findings and renal function outcome. Urinary excretion of Th1, Th2 and Treg/Th17 cytokines were significantly higher in FSNGN compared to IgAN patients. In IgAN patients (n = 50, M/F: 36/14, M age: 40.7 [17-67] years), Th1, Th2 and T17 cytokines correlated significantly with the presence of endocapillary proliferation, while in FSNGN patients (n = 40, M/F: 24/16, M age: 56.5 [25-80] years), MCP-1 and TGF-ß1 had a positive correlation with severe extracapillary proliferation (P = 0.001 and P = 0.002, respectively). Urinary IL-17 was the only independent parameter associated with endocapillary proliferation in IgAN and with MCP-1 urinary excretion in FSNGN. Response to treatment was mainly predicted by IL-6 in IgAN, and by Th2 (IL-4, IL-6), Treg (GM-CSF) cytokines and MIP-1 ß in FSNGN. Th1, Th2 and T17 cytokines were directly implicated in renal pathology in IgAN and possibly through MCP-1 production in FSNGN. IL-17 and IL-6 seem to have a central role in inflammation and progression of kidney injury.
ABSTRACT
BACKGROUND: We evaluated the impact of the three major genetic polymorphisms of the renin-angiotensin system [angiotensinogen (AGT) gene M235T, angiotensin-converting enzyme (ACE) gene-I/D and angiotensin II-type 1 receptor (AT1R) gene A1166C polymorphisms] as risk factors in IgA nephropathy. METHODS: The clinical course of 107 patients with biopsy proven IgA nephropathy followed up for 6.6 +/- 5.8 years was examined. The genetic polymorphisms were determined by PCR amplification. RESULTS: The allele frequencies of the polymorphisms studied were similar in patients and control subjects. AGT-M235T genotype was associated with the presence of nephrotic syndrome (p < 0.05), correlated to the number of antihypertensive drugs agents taken (p < 0.01) and influenced the rate of deterioration of renal function (p < 0.05). Combined analysis of AGT-M235T and ACE-I/D polymorphisms detected an interaction on affecting progression (p < 0.05). ACE-inhibition had a more pronounced effect in certain AGT-M235T and ACE-I/D genotypes (p < 0.05) and their combined analysis showed a synergistic effect (p < 0.01). No association between AT(1)R-A1166C polymorphism and any of the parameters studied was observed. CONCLUSIONS: Our results suggest that angiotensinogen-M235T polymorphism is an important marker of progression in IgA nephropathy in Caucasian patients, especially when analyzed in combination with ACE-I/D polymorphism.
Subject(s)
Glomerulonephritis, IGA/genetics , Polymorphism, Genetic , Renin-Angiotensin System/genetics , Female , Humans , MaleABSTRACT
BACKGROUND/AIMS: We analyzed the influence of angiotensin-converting enzyme (ACE) I/D, angiotensinogen (AGT) M235T and angiotensin-II-type-1 receptor (AT1R) A1166C genetic polymorphisms on the clinical course of focal segmental glomerulosclerosis (FSGS). METHODS: This study consisted of 71 patients with nephrotic syndrome due to biopsy proven FSGS and 100 healthy controls. According to the slope of the reciprocal serum creatinine (1/Cr, >or= or <-0.1 dl x mg(-1) x year(-1)) patients were classified into group A (slow progressors, n = 50) and group B (fast progressors, n = 21). Genotyping was performed using polymerase chain reaction (PCR). RESULTS: There were no relevant differences in the allele frequencies of the investigated polymorphisms between patients with FSGS and controls. Patients carrying the T- allele of the AGT polymorphism required a larger number of antihypertensive agents (MM: 1.35 +/- 1.0 vs. MT/TT: 2.0 +/- 1.2, p < 0.05). The ACE-ID/DD genotypes were more frequently found in patients with fast progression (group A: II: 38.0%, ID/DD: 62.0% vs. group B: II: 14.3%, ID/DD: 85.7%, p < 0.05). The AT1R-A1166C polymorphism was not associated with any of the parameters studied. CONCLUSION: The course of FSGS is in part genetically determined by polymorphisms of the renin-angiotensin-system. The ACE-I/D polymorphism was shown to be a risk factor of progression of renal disease and the AGT-M235T polymorphism was associated with the severity of arterial hypertension.
