No association between a genetic variant of the p22(phox) component of NAD(P)H oxidase and the incidence and progression of IgA nephropathy.
BACKGROUND
The course of glomerulonephritis varies even within the same histological entity, which suggest that genetic factors determine the progression of inflammatory renal diseases. We studied a potential relationship between the C242T gene polymorphism of p22(phox), a subunit of the NAD(P)H oxidase, and frequency as well as progression of immunoglobulin A (IgA) nephropathy. Patients with lupus nephritis were also investigated. The distribution of the C242T gene variation of p22(phox) has not been previously studied in patients with renal disease.


METHODS
Patients with IgA nephropathy were from a homogenous ethnic group of patients living in Northern Germany (n=127). Patients with active lupus nephritis WHO classes III/IV (n=46) were also studied. All diagnoses were confirmed by renal biopsy. Healthy blood donors (n=151) exhibited a genotype distribution similar to previously reported values for Caucasians (CC, 41.2%; CT, 45%; TT, 13.8%). However, C242T genotype distribution was not significantly different (chi(2) test) in patients with IgA nephropathy (CC, 44.9%; CT, 48%; TT, 7.1%) or in active lupus nephritis (CC, 54.3%; CT, 34.7%; TT, 11%). Grouping of IgA nephropathy patients as those with mild renal impairment at the time of biopsy (serum creatinine <1.3 mg/dl) and those with more severe renal failure (serum creatinine >1.3 mg/dl) also failed to show a relationship with p22(phox) polymorphism. Log-rank analysis for up to 15 years in selected cases of IgA nephropathy did not show a significant difference in renal survival rate among the three genotypes.


CONCLUSIONS
It appears that the C242T polymorphism is not associated with IgA nephropathy or active lupus nephritis and may not affect the progressive deterioration of renal function in patients with IgA nephropathy. However, whether the C242T polymorphism plays a role in other renal diseases remains to be studied.
Wolf
Gunter
G
Department of Medicine, Division of Nephrology and Osteology, University of Hamburg, Hamburg, Germany. Wolf@uke.uni-hamburg.de
Panzer
Ulf
U
Harendza
Sigrid
S
Wenzel
Ulrich
U
Stahl
Rolf A K
RA
D001706:Biopsy; D018450:Disease Progression; D014644:Genetic Variation; D005838:Genotype; D005858:Germany; D005922:Glomerulonephritis, IGA / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D015994:Incidence; D007668:Kidney / Q000473:pathology; D026901:Membrane Transport Proteins; D016660:NAD(P)H Dehydrogenase (Quinone) / Q000235:genetics*; D009252:NADPH Dehydrogenase / Q000235:genetics*; D019255:NADPH Oxidases; D010750:Phosphoproteins / Q000235:genetics*
D026901:Membrane Transport Proteins; D010750:Phosphoproteins; D019255:NADPH Oxidases; C086986:CYBA protein, human; D016660:NAD(P)H Dehydrogenase (Quinone); D009252:NADPH Dehydrogenase