sought from multiple referees and related academic societies to prevent the guidelines from being influenced by any conflicts of interest. Drafts were shown to the society members, and revisions were made based on their opinions (public comments). 9. Publication and Future Revisions The Guidelines were published in the Japanese-language journal of the Japanese Society of Nephrology and concurrently released as a Japaneselanguage book (by Tokyo Igakusha, Tokyo). The Guidelines were also uploaded to the homepage of the Japanese Society of Nephrology. At present, CKD-related evidence is being rapidly accumulated, and this new evidence will necessitate the preparation of an updated version of the Guidelines in 3-5 years. A certain degree of turnover in the membership of the revision committee will be required in order to ensure the impartiality of the Guidelines. 1. Disease concept and definition of ADPKD ADPKD is the most common hereditary cystic kidney disease. ADPKD is characterized by the progressive development of fluid-filled cysts derived from renal tubular epithelial cells and the development of disorders in several organs. Bilateral renal cysts enlarge progressively, gradually compromising renal function, and finally, end-stage renal disease (ESRD) requiring renal replacement therapy occurs in approximately 50% of patients by the age of 60 years. The pattern of transmission in ADPKD is autosomal dominant inheritance. A male or female with a mutant allele develops the disease. In case that both parents are unaffected, disease in the offspring results from new mutation. ADPKD is caused by a germ line mutation in PKD1 (16p13.3)(85% of cases) or PKD2 (4q21)(15% of cases). 2. Diagnosis of ADPKD: Symptoms and laboratory findings 1) Algorithm The diagnostic algorithm for ADPKD is depicted in the figure. Family history, while important in ADPKD diagnosis, often cannot be assessed. Moreover, even in the absence of family history, it is important to remain alert to newly reported mutations in PKD1/PKD2 genes responsible for disease onset. It can be difficult to detect cysts meeting diagnostic criteria in younger patients, requiring reexamination. Clinical questions (CQs) are appended to these guidelines as a reference in following the algorithm and determining treatment and other medical care once a definitive diagnosis has been made. Figure 2) Diagnostic criteria Table 1 presents the diagnostic criteria of ADPKD (ADPKD Diagnostic Guidelines, Second Edition, published by a Grant-in-Aid for Progressive Renal Diseases Research, Ministry of Health, Labour and Welfare of Japan). Confirmation or nonconfirmation of family history determines one of two possible protocols, each requiring its own distinctive cyst assessment based not only on ultrasonography (US) but also on computed tomography (CT) and magnetic resonance imaging (MRI). In most cases, cysts manifest bilaterally and diagnosis is uncomplicated; in the remaining cases, diagnosis should be carefully performed in accordance with the diagnostic criteria noted herein. Table 1 the diagnostic criteria of ADPKD (ADPKD Diagnostic Guidelines, Second Edition, published by a Grant-in-Aid for Progressive Renal Diseases Research, Research on intractable disease, from the Ministry of Health, Labour and Welfare of Japan) 1. Confirmation of family history a. Three or more bilaterally-manifested cysts confirmed with ultrasonography b. Five or more bilaterally-manifested cysts confirmed with CT and MRI imaging 2. Non-confirmation of family history a. Patients 15-years old or younger: three or more bilaterally-manifested cysts confirmed with either CT and MRI imaging or ultrasonography b. Patients 16-years old or older: five or more bilaterally-manifested cysts confirmed with either CT and MRI imaging or ultrasonography Diseases to be excluded 1. Multiple simple renal cyst 2. Renal tubular acidosis 3. Multicystic kidney (multicystic dysplastic kidney) 4. Multilocular cysts of the kidney 5. Medullary cystic disease of the kidney (juvenile nephronophthisis) 6. Acquired cystic disease of the kidney 7. Autosomal recessive polycystic kidney disease 3) Comparison of diagnostic criteria between Japan and other countries Following Bear’s diagnostic criteria in 1984, numerous other versions have been reported, each with its own emphasis on, for example, age classification or cyst assessment through imaging. Ravine’s criteria, which were utilized for some time, were the first guidelines reflecting age as a factor. However, Ravine only incorporated PKD1 family history. Although PKD1 and PKD2 mutations each result in almost the same clinical manifestation of the disease, PKD1 progresses to ESRD more rapidly and produces more cysts, leading Pei to incorporate both PKD1 and PKD2 families in his diagnostic criteria. Diagnosis in Western countries combining US with genetic testing is highly credible and should serve as a reference, but its applicability to Japanese patients has not yet been demonstrated. 4) Testing ADPKD screening should include family history of renal disease (end-stage and otherwise) and intracranial hemorrhage/cerebrovascular disease; patient history of hypertension, cerebrovascular disease, urinary tract infection, fever, and lower back pain; subjective symptoms such as macroscopic hematuria, lower back and/or flank pain, abdominal distension, headache, edema, and nausea; physical