In conclusion, early diagnosis,

treatment and improvement of predictive factors for a long duration may lead to better renal prognosis in patients with IgA nephropathy. Chronic kidney disease (CKD) is a worldwide public health issue. The Japanese Society of Nephrology (JSN) sponsored the Asian Forum of CKD initiative (AFCKDI) in the Asia–Pacific region on 27–28 May 2007.1 CKD is defined as kidney damage, as confirmed by renal biopsy or damage markers, or glomerular filtration rate (GFR) of less than 60 mL/min per 1.73 m2 for more than 3 months. Among patients with CKD, the stage of disease is based on GFR level, irrespective of the cause of kidney disease. CKD and cardiovascular disease (CVD) are closely interrelated. The main renal diseases in Japan leading to maintenance dialysis are diabetic nephropathy, chronic glomerulonephritis (mainly PF01367338 immunoglobulin (Ig)A nephropathy) Proteasomal inhibitor and hypertensive nephrosclerosis. IgA nephropathy is one of the

major causes of CKD in Japan. Despite statutory urinalysis of industrial workers and school children, Japan unfortunately still ranks among the countries with the highest CKD-5D prevalence in the world. In 1968, Berger2 first reported ‘Nephropathy with mesangial IgA and IgG deposits’. IgA nephropathy is chronic mesangial proliferative glomerulonephritis associated with IgA and IgG deposits observed by immunofluorescence (Fig. 1). IgA nephropathy is the most common primary glomerulonephritis in the world. Genetic factors are considered to be involved in the initiation and progression of IgA nephropathy on the basis of racial differences in prevalence and familial aggregation. In Juntendo University, IgA nephropathy was observed selleckchem in 704 out of 1251 patients (56.3%) with primary glomerular diseases diagnosed by renal biopsy from 1978 to 2008. IgA nephropathy is

considered to be an aberrant polymeric IgA1-mediated chronic proliferative glomerulonephritis and approximately 40% of the patients potentially develop end-stage kidney disease (ESKD) within 20 years (Fig. 2). Topics of this review are as follow: (i) early diagnosis and treatment; (ii) influence of the period from onset to medical intervention on renal prognosis; and (iii) epidemiology of IgA nephropathy patients in Japan. Although the diagnosis cannot be established without renal biopsy, several clinical markers that correlate well with the diagnosis and prognosis of IgA nephropathy have been reported. Some investigators have discussed the possibility of predicting the diagnosis and prognosis of this disease.3,4 Maeda et al.5 and Nakayama et al.,6 my colleagues, reported important clinical markers to distinguish between IgA nephropathy and non-IgA nephropathy prior to renal biopsy such as: (i) more than five red blood cells in urinary sediments; (ii) persistent proteinuria of more than 0.3 g/day; (iii) serum IgA levels of more than 315 mg/dL and serum IgA/C3 ratio of more than 3.01.