Naoyasu Sugishita

Sex differences in acquired cystic disease of the kidney on long-term dialysis.

Acquired cystic disease of the kidney in chronic glomerulonephritic patients who had been on hemodialysis more than 3 years (4.5 +/- 1.2 years at the base line examination), were followed for 3.6 +/- 0.5 years (at the follow-up examination) by computed tomography (CT scan). The renal volume in the 25 male patients was significantly greater at the follow-up examination than at the base line examination. On the other hand, the renal volume in the 12 female patients was similar on both examinations. The enlargement of kidney volume more than twofold during the follow-up was seen in 9 of 25 male and none of 12 female patients. The grade of cystic transformation was increased in male patients during the follow-up period. These results indicate that sex-related endogenous substances might play a role in the pathogenesis of acquired cystic disease.

Asymmetric hypertrophy of renal graft after transplantation.

Isao Ishikawa, MD, Division of Nephrology, Department of Internal Medicine, Kanazawa Medical University, Uchinada, Kahoku, Ishikawa 920-02 (Japan) Since the cortical thickness of the graft is thinner at contact with the psoas muscle [1], it is suggested that the local mechanical effect of the recipient affects the graft hypertrophy, i.e. the upper part of the graft facing the upper abdomen hypertrophies more than the lower part facing the minor pelvis where there is no space to move. In order to prove this hypothesis, renal volume was measured using CT scan in its upper, hilar and lower parts. Six recipients (25.3 ± 7.9 years of age, mean ± SD) received grafts from their parents (53.2 ± 5.6 years of age). CT scans were performed from the upper pole to lower pole of the kidney sequentially with a constant slice width (8 mm), 77 ± 43 days before transplantation and 75 ± 28 days after transplantation for grafts and 42 ± 36 days after transplantation for donor’s remaining kidneys. The donor’s left kidney was transplanted in the right iliac fossa of the recipient inside out. The serum creatinine levels in 6 recipients were 1.0–1.5 mg/dl at the time of CT examination after transplantation. The upper or lower parts of the kidney were defined as kidney part above the uppermost scan level or below the lowest scan level where the hilus is included. The hilar part was defined as the renal part with scan slices including the renal hilus. The volumes of the upper, hilar and lower parts were measured in 35 recipients who received the donor’s left kidney in their right iliac fossa besides 6 donor and recipient pairs. The angle of the axis of the graft to the median line in 6 recipients (1.2 ± 5.7°) is significantly more upright than the axis of the left kidney in the donor (-12.4 ± 7.6°) (p < 0.05). Therefore, the volume of the upper part of the graft is underestimated and the volume of the lower part is overestimated because the axis of the graft is more upright.

Blood pressure changes and renal transplantation

腎移植前の血液透析療法時の血圧と術後の血圧の関連, およびこれに関与する因子について検討した. 1975年3月以降生体腎移植を受け, 2ヵ月以上生着して3年間経過を観察し得た72例を対象とした. 術前の週3回の人院透析中は30例 (42%) に高血圧が, 8例 (11%) に低血圧をみられた. 腎移植後は48例 (67%) に高血圧が出現したが, 術前高血圧があった例は術後もひき続き高血圧を示すことが多かった. 急性拒絶反応のepisodeが0-1回と2回以上では2回以上に有意に高血圧が多く, また慢性拒絶反応がみられたものは3例を除き18例が高血圧を呈した.腎移植前の血漿レニン活性 (PRA) と移植後の血圧の間には関連がなかったが, 移植後高血圧のある群はないものよりPRAが高値を示した. 少数例での分腎レニン活性測定ではすべて原病腎からのPRAは移植腎のそれを上回り, 原病腎からのレニン分泌増加を示唆した.移植後腎動脈狭窄で治療を要したものは1例のみであった. 移植後の高血圧は難治例が少なく, 約2/3の症例が2剤以内の降圧薬でよくコントロールされた.移植前に低血圧を示した例が8例あり, うち4例は両側腎摘除を受けていた. 5例に術後, 乏尿性急性腎不全が起きたが, 8例とも手術の翌日には血圧が正常化していた.以上より, 高血圧は腎移植後の頻度の高い合併症であり, その原因としては術前の高血圧の持続と慢性拒絶反応が重要である. 術前より高血圧が持続する例ではレニン分泌過剰が主要機序と考えられる. 術前の低血圧はとくに無腎例に多くみられ, 腎移植により速やかに正常化し, その過程よりみて健常腎組織に関連する体液性因子の関与が考えられる.