Radiation-induced renal disease. A clinicopathologic study

Borane-protected phosphines are redox-active radioprotective agents for endothelial cells

Exposure to radiation can damage endothelial cells in the irradiated area via the production of reactive oxygen species. We synthesized phosphine–borane complexes that reduce disulfide bonds and had previously been shown to interfere with redox-mediated signaling of cell death. We hypothesized that this class of drugs could interfere with the downstream effects of oxidative stress after irradiation and rescue endothelial cells from radiation damage. Cultured bovine aortic endothelial cells were plated for clonogenic assay prior to exposure to varying doses of irradiation from a ¹³⁷Cs irradiator and treated with various concentrations of bis(3-propionic acid methyl ester)phenylphosphine borane complex (PB1) at different time points. The clone-forming ability of the irradiated cells was assessed seven days after irradiation. We compared the radioprotective effects of PB1 with the aminothiol radioprotectant WR1065 and known superoxide scavengers. PB1 significantly protected bovine aortic endothelial cells from radiation damage, particularly when treated both before and after radiation. The radioprotection with 1 µM PB1 corresponded to a dose-reduction factor of 1.24. Radioprotection by PB1 was comparable to the aminothiol WR1065, but was significantly less toxic and required much lower concentrations of drug (1 µM vs. 4 mM, respectively). Superoxide scavengers were not radioprotective in this paradigm, indicating the mechanisms for both loss of clonogenicity and PB1 radioprotection are independent of superoxide signaling. These data demonstrate that PB1 is an effective redox-active radioprotectant for endothelial cells in vitro, and is radioprotective at a concentration approximately 4 orders of magnitude lower than the aminothiol WR1065 with less toxicity.

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Phosphine–borane complexes (PB) reduce disulfide bonds and modulate redox signaling.

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PB1 protects endothelial cells from radiation damage before and after radiation.

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Radioprotection with PB1 is independent of superoxide signaling.

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PB1 radioprotection is similar to WR1065, but with less toxicity and more potency.

Thrombotic microangiopathy in metastatic melanoma patients treated with adoptive cell therapy and total body irradiation

BACKGROUND

Thrombotic microangiopathy (TMA) is a complication that developed in some patients receiving 12 Gy total body irradiation (TBI) in addition to lymphodepleting preparative chemotherapy prior to infusion of autologous tumor-infiltrating lymphocytes (TIL) with high-dose aldesleukin (IL-2). This article describes the incidence, presentation, and course of radiation-associated TMA.

METHODS

The data for patients with metastatic melanoma who received ACT with TIL plus aldesleukin following myeloablative chemotherapy and 12-Gy TBI was examined, in order to look at patient characteristics and the natural history of TMA.

RESULTS

The median time to presentation was approximately 8 months after completing TBI. The estimated cumulative incidence of TMA was 31.2% (median follow-up of 24 months). Noninvasive criteria for diagnosis included newly elevated creatinine levels, new-onset hypertension, new-onset anemia, microscopic hematuria, thrombocytopenia, low haptoglobin, and elevated lactate dehydrogenase values. Once diagnosed, patients were managed with control of their hypertension with multiple agents and supportive red blood cell transfusions. TMA typically stabilized or improved and no patient progressed to dialysis. TMA was associated with a higher probability of an antitumor response.

CONCLUSIONS

TMA occurs in approximately a third of patients treated with a lymphodepleting preparative chemotherapy regimen with TBI prior to autologous T cell therapy. The disease has a variable natural history, however, no patient developed end-stage renal failure. Successful management with supportive care and aggressive hypertension control is vital to the safe application of a systemic therapy that has shown curative potential for patients with disseminated melanoma.

Radiation-associated kidney injury

The kidneys are the dose-limiting organs for radiotherapy to upper abdominal cancers and during total body irradiation. The incidence of radiotherapy-associated kidney injury is likely underreported owing to its long latency and because the toxicity is often attributed to more common causes of kidney injury. The pathophysiology of radiation injury is poorly understood. Its presentation can be acute and irreversible or subtle, with a gradual progressive dysfunction over years. A variety of dose and volume parameters have been associated with renal toxicity and are reviewed to provide treatment guidelines. The available predictive models are suboptimal and require validation. Mitigation of radiation nephropathy with angiotensin-converting enzyme inhibitors and other compounds has been shown in animal models and, more recently, in patients.

Impact of drug therapy, radiation dose, and dose rate on renal toxicity following bone marrow transplantation

PURPOSE

To demonstrate a radiation dose response and to determine the dosimetric and chemotherapeutic factors that influence the incidence of late renal toxicity following total body irradiation (TBI).

METHODS AND MATERIALS

A comprehensive retrospective review was performed of articles reporting late renal toxicity, along with renal dose, fractionation, dose rate, chemotherapy regimens, and potential nephrotoxic agents. In the final analysis, 12 articles (n = 1,108 patients), consisting of 24 distinct TBI/chemotherapy conditioning regimens were included. Regimens were divided into three subgroups: adults (age > or =18 years), children (age <18 years), and mixed population (both adults and children). Multivariate logistic regression was performed to identify dosimetric and chemotherapeutic factors significantly associated with late renal complications.

RESULTS

Individual analysis was performed on each population subgroup. For the purely adult population, the only significant variable was total dose. For the mixed population, the significant variables included total dose, dose rate, and the use of fludarabine. For the pediatric population, only the use of cyclosporin or teniposide was significant; no dose response was noted. A logistic model was generated with the exclusion of the pediatric population because of its lack of dose response. This model yielded the following significant variables: total dose, dose rate, and number of fractions.

CONCLUSION

A dose response for renal damage after TBI was identified. Fractionation and low dose rates are factors to consider when delivering TBI to patients undergoing bone marrow transplantation. Drug therapy also has a major impact on kidney function and can modify the dose-response function.

The Importance of Age, Fludarabine, and Total Body Irradiation in the Incidence and Severity of Chronic Renal Failure after Allogeneic Hematopoietic Cell Transplantation

Nonmalignant late effects, including chronic renal failure (CRF), impair the quality of life of long-term survivors after allogeneic hematopoietic cell transplantation. One of the major risk factors is the use of total body irradiation (TBI) in the preparative regimen; TBI is currently fractionated in an attempt to reduce toxicity. We analyzed 241 patients who had TBI-based preparative regimens for allogeneic hematopoietic cell transplantation. TBI was delivered as a single fraction of 7.5 Gy (7.5S group), 12 Gy in 6 fractions (12F group), or 14.4 Gy in 8 fractions (14.4F group). The cumulative incidence of CRF at 2 years was 12%. Statistical analysis revealed that older age (P < .001) and fludarabine administration (P = .016) had a significant effect on the incidence of CRF. Furthermore, single-fraction TBI was also significantly associated with CRF severity, because 7 (6.3%) of 111 patients in the 7.5S group developed severe CRF, as opposed to 1 (0.8%) of 130 patients in the 12F and 14.4F groups combined (P = .044). However, these conclusions should be regarded as preliminary in view of the retrospective and nonrandomized nature of this study.

Retinoic acid may increase the risk of bone marrow transplant nephropathy

Bone marrow transplant nephropathy (BMTN) classically presents more than 100 days after transplantation as an acute nephritis with hypertension, azotaemia and anemia that usually results in end stage renal failure (ESRF). The risk of developing BMTN may be greater with the use of more intensive chemotherapy and higher total body and tumor bed irradiation. Cis-retinoic acid (RA) may further increase the risk of developing BMTN. Here, we report the cases of two children who developed typical clinical and biochemical features of BMTN. They were both treated for stage IV neuroblastoma with chemotherapy, bone marrow transplant (BMT) conditioning that included total body irradiation and RA therapy after BMT, although the patient in case 1 had established renal insufficiency prior to the commencement of RA. Renal biopsy of these children showed classical BMTN histology, and the renal manifestations progressed quickly; the patient in case 1 became dialysis dependent by 1 year post-bone marrow transplant. Recently, RA has been added to the post-BMT therapy in children with stage IV neuroblastoma. The occurrence of BMTN in two children treated with RA in our unit is unlikely to be coincidental. Although RA has been shown to confer a significant survival advantage in this disease, animal studies and a previous case report have suggested it could increase the toxic effects of chemotherapy and renal irradiation. It is likely that RA contributed to the deterioration in renal function in these patients.

Renal toxicity after total body irradiation

PURPOSE

To evaluate the incidence of renal dysfunction after total body irradiation (TBI).

METHODS AND MATERIALS

Between 1990 and 1997, 64 patients (median age 50 years) received TBI as part of the conditioning regimen before bone marrow transplantation (BMT). Five patients with abnormal renal function at the beginning of treatment or with incomplete data were excluded. All patients received a total of 12 Gy (6 fractions twice daily for 3 consecutive days) prescribed to the peak lung dose (corrected for lung transmission) at a dose rate of 7.5 cGy/min. Renal shielding was not used. Renal dysfunction was assessed on the basis of the serum creatinine levels measured at the start and end of TBI and at 6, 12, 18, and 24 months after completion of BMT. Cox proportional hazard analysis was used to evaluate the various factors known to affect renal function.

RESULTS

Only 4 patients had elevated serum creatinine levels at 12 months and subsequently only 2 of the 33 surviving patients had persistent elevated renal serum creatinine levels 24 months after BMT. A fifth patient developed proteinuria and mildly elevated serum creatinine levels at 2.5 years. In 2 patients, the elevation coincided with disease relapse and normalized once remission was achieved. In the third patient, the elevation in serum creatinine levels coincided with relapse of multiple myeloma and the presence of Bence-Jones proteinuria. The fourth patient was the only patient who developed chronic renal failure secondary to radiation nephritis at 2 years. The etiology of the fifth patient's rise in creatinine was unknown, but may have been secondary to radiation nephritis. On univariate analysis, but not on multivariate analysis, a significant correlation was found between TBI-related renal dysfunction and hypertension before and after BMT.

CONCLUSION

A dose of 12 Gy at 2 Gy/fraction resulted in only 1 case of radiation nephritis in the 59 patients studied 24 months after the completion of TBI and BMT.

Angiotensin II blockade reduces radiation-induced proliferation in experimental radiation nephropathy

Total-body irradiation or renal irradiation is followed by a well-defined sequence of changes in renal function leading eventually to renal failure. Previous studies in a rat model have shown that inhibition of angiotensin-converting enzyme or blockade of angiotensin II receptors can prevent the structural and functional changes that occur after renal irradiation, and that these interventions are particularly important between 3 and 10 weeks after irradiation. We have now shown that in the same rat model, total-body irradiation induces proliferation of renal tubular cells (i.e., an increase in the number of cells staining positive for proliferating cell nuclear antigen) within 5 weeks after irradiation. Treatment with an angiotensin II receptor blocker delays this radiation-induced tubular proliferation and decreases its magnitude. Renal radiation also induces proliferation of glomerular cells, but the relative increase in glomerular proliferation is not as great as that seen in renal tubular cells, and the increase is not delayed or decreased by treatment with an angiotensin II receptor blocker. We hypothesize that angiotensin II receptor blockers exert their beneficial effect in radiation nephropathy by delaying the proliferation (and hence the eventual mitotic death) of renal tubular cells that have been genetically crippled by radiation.

Endothelial cell loss in irradiated optic nerves

OBJECTIVE

Radiation optic neuropathy usually occurs months to years after exposure of the anterior visual pathways to ionizing radiation. It is characterized by high signal on gadolinium-enhanced T1-weighted magnetic resonance imaging. Radiation-induced endothelial cell damage resulting in blood-nerve barrier breakdown is hypothesized to produce this pattern, but histologic evidence of this in the optic nerve is lacking. We attempted to evaluate the effect of radiation on endothelial cells in the optic nerve.

DESIGN

Case-controlled histologic study.

METHODS

We studied the optic nerves of 16 enucleated eyes from patients with uveal melanoma treated with proton beam irradiation, 6 from normal eyes and 5 from eyes with unirradiated uveal melanomas. Binding of Ulex europaeus agglutinin I (UEA-I) lectin was used to identify endothelial cells in single paraffin sections. Transverse and longitudinal sections of vessels were counted in masked fashion.

RESULTS

There were 49.4+/-6.9 transversely sectioned endothelial cells per millimeter of nerve in 6 optic nerves exposed to 0 to 1000 cGyE ("low-dose") compared with 17.3+/-5.3 in 10 nerves exposed to 5500 to 7000 cGyE ("high-dose") (P = 0.002). Longitudinally sectioned vessels stained with UEA-I were separately identified, with 11.5+/-2.1 in the low-dose group and 5.6+/-1.6 in the high-dose group (P = 0.044). The thickness and staining of the endothelial cell layer appeared greater in the high-dose group. Endothelial cell counts did not correlate with age, gender, acuity, or interval after irradiation.

CONCLUSIONS

Increased radiation dosage to the optic nerve correlates with smaller numbers of endothelial cells.

Long-term evolution of renal function in patients with ovarian cancer after whole abdominal irradiation with or without preceding cisplatin

BACKGROUND

The upper limit of the natural decline in creatinine clearance is 1 ml/min/year. To define the loss of renal function, we started a long-term assessment of patients with ovarian cancer treated by whole abdominal irradiation (WAI) with preceding cisplatin chemotherapy (CDDP) and second-look laparotomy (SLL).

PATIENTS AND METHODS

We analyzed the creatinine clearance over time of 56 patients treated from 1982 to 1988 for ovarian cancer. Thirty-one of 56 patients had received WAI after their initial surgery, and 25 of 56 patients had undergone CDDP therapy followed by SLL, and then WAI after their initial surgery. Median follow-up was 99 months (7-156). Twenty of 56 patients accepted our invitation for additional assessment of tubular function, nine of the 31 patients without CDDP therapy and SLL, and 11 of the 25 patients with CDDP followed by SLL and WAI. Ten of twenty patients had received four to six cycles CDDP, 80 mg/m2/cycle, and one patient nine cycles. The median total dose for each kidney was 1450 cGy (480-1690).

RESULTS

The mean creatinine clearance decreased from 84 ml/min to 66 ml/min. Seventy-six percent of the 25 patients who had undergone CDDP therapy, SLL and WAI had declines of more than 1 ml/min/year, 64% of these patients of more than 2 ml/min/year. For the 31 patients who had received WAI after their initial surgery, the corresponding numbers were 71% and 55%, respectively. The tubular function of the 20 patients who had undergone the additional investigations was not impaired.

CONCLUSION

The decline in renal function after WAI is more pronounced than in healthy subjects. The treatment with cisplatin and SLL prior to WAI does not seem to contribute to this loss of kidney function.

Compensatory hypertrophy and progressive renal damage in children nephrectomized for Wilms' Tumor

Clinical, biochemical, and sonographic evaluation of the remaining kidney function and size was performed in 34 patients, 12 males and 22 females, ages 2.1-19.6 years, nephrectomized (NP) for Wilms' tumor (WT) at least 2 years before (mean 8.6). All patients had normal blood pressure and serum bicarbonates. Two of them had microhematuria, four proteinuria 4 mg/m2/hr, and 11 microalbuminuria (MA) > 20 mg/24 hr. Only one patient had reduced creatinine clearance and maximum bipolar length (MBL) as well as kidney volume (KV) < 100% of expected. In the other patients, average MBL was 128 +/- 11% (P = 0.0001). MBL, but not KV, was inversely correlated (P = 0.04) to age at NP. KV, but not MBL, was directly correlated (P = 0.009) to MA. Average MA was 48 +/- 94 mg/24 hr and was correlated to the time from NP (P = 0.026). The remaining kidney increases in volume much more than in length. The increase in KV is related to the degree of MA, whereas the increase in MBL is higher in subjects younger at NP. The high prevalence of significant MA, which is in turn related to the time from NP and to the KV, raises some concerns about the long-term renal prognosis of children NP for WT.

Evidence for a renovascular component in hypertensive patients with late radiation nephropathy

PURPOSE

This study was undertaken to investigate whether the hypertension observed in a subgroup of patients with progressive radiation-induced nephropathy has a renovascular component.

METHODS AND MATERIALS

Fifteen patients with prospectively documented renal injury after high-dose radiation treatment for various abdominal malignancies were studied, 8 of them having hypertension. 99mTc-DTPA renography and plasma renin activity measurements were performed before and after an oral dose of 50 mg captopril. In patients with a positive captopril renography, a selective angiography was performed to exclude preexisting central renal artery stenosis and to assess the type and extent of the vascular changes.

RESULTS

The captopril 99mTc-DTPA renography demonstrated a longer time until maximal renal activity (Tmax) compared with the baseline study in five out of eight hypertensive patients. This increase in Tmax was observed in both high-dose (40 Gy/5.5 weeks) and in low-dose (12-13 Gy/3 weeks) irradiated kidneys. No increase in Tmax was observed in the normotensive patients. In the five hypertensive cases with an increased Tmax, selective angiography demonstrated severe stenotic and tortuous changes in the small intrarenal branches of the high-dose irradiated kidneys without stenosis of the main renal artery. Captopril induced an increase in peripheral plasma renin activity in the hypertensive group, but not in the normotensive patients.

CONCLUSION

These data suggest a radiation-induced hypertension, mediated by the renin-angiotensin system due to damage in predominantly small renal arteries. It was possible to demonstrate hypertensive changes with a captopril 99mTc-DTPA renography, even after presumed subthreshold radiation doses for clinical radiation nephropathy.

Single dose versus fractionated total body irradiation before bone marrow transplantation: radiobiological and clinical considerations

PURPOSE

This present review is intended to evaluate the specific influence of fractionation of total body irradiation on the outcome of a subsequent bone marrow transplantation.

METHODS AND MATERIALS

Available experimental and clinical data on the influence of fractionation on leukemia cell killing, immunosuppression, and sparing of normal tissues were analyzed.

RESULTS

Review of available data shows: (a) The role of fractionation on leukemia cell killing may vary with the leukemia type. For acute nonlymphoblastic leukemia, a few experimental and several clinical studies show no or little fractionation effect; a 12-13 Gy fractionated scheme could, therefore, be more efficient than a conventional 10 Gy single dose total body irradiation. For chronic myelogenous leukemia, some sensitivity to fractionation is suggested, so that an increase in total or fractional dose may be necessary in fractionated schemes to equate the efficacy of a 10 Gy single dose. For acute lymphoblastic leukemia, a high fractionation sensitivity was observed for some leukemic cell lines in vitro, without undisputable clinical confirmation for the moment. (b) Numerous experimental studies have demonstrated that the immunosuppressive effect of total body irradiation, a major determinant of engraftment, is highly fractionation sensitive. In humans, high rates of graft failures have been reported when T-cell depletion of the graft was associated to fractionated total body irradiation schedules. (c) A large amount of radiobiological and clinical data have demonstrated that late radiation-induced injuries to normal tissues and organs are highly fractionation sensitive. However, in a context of total body irradiation for bone marrow transplantation, the number of other determinants of normal tissue damage makes it difficult to demonstrate a clear-cut advantage of fractionated over single dose scheme, with a possible exception for children.

CONCLUSIONS

In 1994, available data suggest that very cautious attempts could be made to adapt total body irradiation schedules to the potential normal tissue toxicity, T-cell depletion, and to the type of leukemia.

Effect of nephrotoxic drugs on the development of radiation nephropathy after bone marrow transplantation

PURPOSE

Chronic renal failure is a significant cause of late morbidity in bone marrow transplant patients whose conditioning regimen includes total body irradiation (TBI). Radiation is a major cause of this syndrome (bone marrow transplant nephropathy), but it may not be the only cause. These studies use a rat syngeneic bone marrow transplant model to determine whether nephrotoxic agents used in conjunction with bone marrow transplantation (BMT) could be enhancing or accelerating the development of radiation nephropathy.

METHODS AND MATERIALS

Rats received 11-17 Gy TBI in six fractions over 3 days followed by syngeneic bone marrow transplant. In conjunction with the bone marrow transplants, animals received either no drugs, cyclosporine, amphotericin, gentamicin, or busulfan. Drugs were given in schedules analogous to their use in clinical bone marrow transplantation. Drug doses were chosen so that the drug regimen alone caused detectable acute nephrotoxicity. Animals were followed for 6 months with periodic renal function tests.

RESULTS

Gentamicin had no apparent interactions with TBI. Amphotericin increased the incidence of engraftment failure, but did not enhance radiation nephropathy. Cyclosporin with TBI caused late morbidity that appeared to be due to neurological problems, but did not enhance radiation nephropathy. Busulfan resulted in a significant enhancement of radiation nephropathy.

CONCLUSION

Of the nephrotoxins used in conjunction with bone marrow transplantation only radiation and busulfan were found to be risk factors for bone marrow transplant nephropathy.

Acute, subacute, and chronic x-ray effects on glomerular hemodynamics in rats

In order to evaluate the effects of x-rays on glomerular hemodynamics, surgically exposed left kidneys of Munich-Wistar rats were irradiated with 15 Gy in a single dose. The animals were studied 45 min (acute group, n = 8), 14 days (subacute group, n = 7), and 60 days (chronic group, n = 7) after irradiation and compared with their respective controls. A decrease in total glomerular filtration (55%) and renal plasma flow (40%) rates with marked elevation of total renal vascular resistance (180%), p < 0.05, occurred within 45 min. Significant changes also occurred in the microcirculation; i.e., single-nephron glomerular filtration (SNGFR), glomerular plasma flow (QA), and glomerular capillary hydraulic pressure (PGC) declined by 35%, 40%, and 12%, respectively, due to an increase in total arteriolar resistance (90%), p < 0.05. Within 14 days, SNGFR was similar to control in spite of a moderate elevation of afferent arteriolar resistance (26%) and reduction in PGC (11%), p < 0.05, and QA (20%). Kf was significantly elevated (46%), p < 0.05. The chronic group presented a response pattern similar to that of the acute group, although less severe. Histopathological changes were not relevant and were restricted to tubules. The present results suggest that: (a) Acutely, there was a marked reduction in filtration, flow, and PGC with significant elevation of resistances. (b) Within 14 days, the maintenance of SNGFR was probably the result of an offsetting effect between QA and PGC decreases and Kf elevation. (c) After 60 days, the homeostatic mechanism was not sufficient to maintain normal renal function. (d) A functional effect is probably the most important pathogenetic mechanism, at least during the initial phase, for the development of radiation nephropathy since no morphological alterations were observed.

Late renal dysfunction in adult survivors of bone marrow transplantation

Until recently long-term renal toxicity has not been considered a major late complication of bone marrow transplantation (BMT). Late renal dysfunction has been described in a pediatric population status post-BMT which was attributable to the radiation in the preparatory regimen. A thorough review of adults with this type of late renal dysfunction has not previously been described. Fourteen of 103 evaluable adult patients undergoing allogeneic (96) or autologous (7) bone marrow transplantation, predominantly for leukemia and lymphomas, at the Medical College of Wisconsin (Milwaukee, WI) have had a syndrome of renal insufficiency characterized by increased serum creatinine, decreased glomerular filtration rate, anemia, and hypertension. This syndrome developed at a median of 9 months (range, 4.5 to 26 months) posttransplantation in the absence of specific identifiable causes. The cumulative probability of having this renal dysfunction is 20% at 1 year. Renal biopsies performed on seven of these cases showed the endothelium widely separated from the basement membrane, extreme thickening of the glomerular basement membrane, and microthrombi. Previous chemotherapy, antibiotics, and antifungals as well as cyclosporin may add to and possibly potentiate a primary chemoradiation marrow transplant renal injury, but this clinical syndrome is most analogous to clinical and experimental models of radiation nephritis. This late marrow transplant-associated nephritis should be recognized as a potentially limiting factor in the use of some intensive chemoradiation conditioning regimens used for BMT. Some selective attenuation of the radiation to the kidneys may decrease the incidence of this renal dysfunction.

Radiation injury in the human kidney: a prospective analysis using specific scintigraphic and biochemical endpoints

Renal function was prospectively analyzed in 26 evaluable patients, irradiated to various doses on their kidneys for neoplastic disease. Glomerular function was assessed by 99mTc-DTPA renography, creatinine clearance, and serum beta 2-microglobulin, whereas tubular function was monitored by 99mTc-DMSA scintigraphy, urine beta 2-microglobulin, urine N-acetyl glucosaminidase, and alanine aminopeptidase and a urine concentration test. In the patients given the highest irradiation dose to the entire left kidney, that is, 40 Gy in 5 1/2 weeks, glomerular and tubular functional impairment, as assessed scintigraphically, progressed at a rate of 2.0 +/- 1.0% (+/- 1 SD) and 2.0 +/- 0.5% per month, respectively, down to 30-40% after 3 to 5 years. The overall glomerular function, as assessed by creatinine clearance, decreased by only 20%. In the patients irradiated unilaterally on the upper pole to 40 Gy in 4 weeks, glomerular and tubular function in the left kidney deteriorated at 0.75 +/- 0.33% and 0.75 +/- 0.20% per month in the first 2 years, down to 75-80% at 5 years. This smaller reduction was due to shielding of a part of the left kidney. No changes were observed, thus far, after bilateral whole kidney irradiation to 17-18 Gy in 3 1/2 weeks. The concentration capacity of the kidney after total volume irradiation was not impaired. There was a trend for an increase in diastolic blood pressure in 3 out of 5 patients given the high dose irradiation to the entire left kidney and in 2 out of 7 patients irradiated on the upper pole of the left kidney. The progressive nature of the radiation nephropathy stresses the need for long term follow-up to determine more accurately the "tolerance dose" of the human kidney for irradiation.

Late complications following total-body irradiation and bone marrow rescue in mice: predominance of glomerular nephropathy and hemolytic anemia

Late mortality and pathology were assessed in various mouse strains following total-body irradiation (TBI) and bone marrow transplantation. A, C57BL/6, B6AF1, LP and C3H mice received TBI in two fractions 3 h apart at total doses of between 11 and 15 Gy. They were then transplanted with syngeneic bone marrow cells providing sufficient reconstitution to avoid hemopoietic failure. Long-term survival data revealed both radiation dose- and strain-dependent onset of mortality between 1 and 2 years post-treatment. Renal damage appeared to have contributed to the late mortality in most treatment groups as shown by glomerular lesions, elevated blood urea nitrogen and an accompanying fall in hematocrit. Hemolysis was deduced to be the major cause of anemia, as concluded from results of 51Cr-labeled erythrocyte survival. No decrease in erythropoiesis was evident as seen from spleen and bone marrow 59Fe uptake. These findings are together consistent with the manifestation of a hemolytic uremic syndrome (HUS) with kidney glomeruli representing the principal sites of injury responsible for both renal dysfunction and microangiopathic hemolysis.

Long-term follow-up after unilateral nephrectomy and radiotherapy for Wilms' tumour

Twenty-nine patients who had had unilateral nephrectomy for Wilms' tumour in one hospital were known to have survived more than 12 years. Sixteen agreed to attend for clinical review, of whom 14 had estimation of serum creatinine, 24-h urine protein excretion and endogenous creatinine clearance. The follow-up period was 13-26 years (median 17 years). All but one had had radiotherapy and all had chemotherapy (actinomycin D, 16; vincristine, 5). Some degree of kyphoscoliosis was present in all except the patient who did not receive radiotherapy. Four patients had diastolic blood pressure 90 mmHg or greater. Two patients had mild proteinuria (392, 361 mg/day). Serum creatinine ranged from 53 to 125 mumol/l and endogenous creatinine clearance ranged from 39 to 173 ml/min (median 81, mean 89). Of the 7 patients who were 20-26 years post-nephrectomy, 2 were hypertensive and 1 had elevated urinary protein excretion. We conclude that the long-term prognosis of unilateral nephrectomy in childhood is good.

Late tissue-specific toxicity of total body irradiation and busulfan in a murine bone marrow transplant model

Total body irradiation (TBI) and busulfan were compared for late effects in a murine model of bone marrow transplantation (BMT). Male C57BL/6 mice were given fractionated TBI or busulfan given in 4 equal daily doses followed by infusion of 10(7) syngeneic bone marrow cells. Total doses of 16.4 Gy TBI and 3.4 mg busulfan were chosen for their equivalence in inducing near complete engraftment of allogeneic marrow from donor mice of the LP strain. The two treatment groups had a late wave of mortality starting at about 80 weeks after transplantation. Specific tissue damage was manifested in bone marrow stem cells, splenic T-cell precursors, hair greying and cataract formation for both TBI and busulfan but to varying degrees. Severe nephrotoxicity and anemia were observed only after TBI. Although both busulfan and TBI kill early marrow stem cells and are effective preparative agents in bone marrow transplantation, their effects on other stem cell and organ systems are not similar. In addition, many of the injuries seen are late to occur. The delayed expression of injury deserves careful long-term evaluation of BMT recipients before the therapeutic potential of effective preparative regimens can be fully appreciated.

Delayed renal failure with extensive mesangiolysis following bone marrow transplantation

Within two years we have had the opportunity of observing seven leukemic children who were referred to our Pediatric Nephrology Unit for delayed renal failure following bone marrow transplantation (BMT). These children (3 to 12 years old), six with acute lymphoblastic leukemia (ALL) and one with acute non-lymphoblastic leukemia (ANLL), underwent BMT (4 autologous BMT, 3 allogeneic BMT) after the first remission in two, and after the second remission in five. Preparative regimen for BMT included cyclosphosphamide in three, cyclosphosphamide, vepeside and cytosine A in four, and a total body irradiation in a single dose of 10 grays (1000 R) in all of them. Three children were treated immediately after grafting with low dose cyclosporine for four to six months. Five to 10 months after BMT, four patients developed a hemolytic uremic syndrome with severe hypertension. The remaining three were found to have isolated renal insufficiency several months post-BMT. In the seven patients, renal biopsy showed a uniform pattern of severe glomerular involvement characterized by extensive lesions of mesangiolysis associated with severe arteriolonecrosis. A repeat biopsy performed one year later, in two patients showed severe scarring of the renal parenchyma with minor lesions of mesangiolysis. The similarity of the pathologic features observed suggests that the same mechanism might have been operative in the seven patients. It is very likely that the nephropathy is related to total body irradiation enhanced by chemotherapy. We conclude that current treatments of high risk leukemia might become a new cause of chronic renal failure. Further investigations are needed to know the exact incidence of this complication.

Mesangiolytic glomerulopathy in a bone marrow allograft recipient

A boy with null-cell leukemia received a bone marrow allograft after preparation with chemotherapy and total body irradiation. Cyclosporine A was not administered following transplantation. Renal biopsy performed 6 months after transplantation because of unexplained deterioration of renal function revealed diffuse mesangiolysis and glomerular sclerosis. The significance of this finding is discussed with reference to similar, recently reported cases.

Effects of radiofrequency radiation on rabbit kidney: a morphological and immunological study

The histopathology of the acute and chronic kidney reaction to low-frequency nonionizing electromagnetic radiation was evaluated in New Zealand white rabbits treated with multiple exposure to 27.12-MHz radiofrequencies. At the end of treatment, the animals exhibited focal tubular necrosis and focal and segmental glomerular sclerosis which in a few months evolved into a membranous nephropathy. The latter was characterized by a diffuse, granular localization of rabbit gamma-globulin and complement in most glomeruli and by electron-dense deposits in the subepithelial zone of the glomerular capillary walls, suggesting that these glomerular changes are induced by the localization of antigen-antibody complexes. The data obtained provide strong evidence for the potential nephrotoxicity of radiofrequency radiation and indicate that these nonionizing types of radiation may be capable of eliciting autoimmune phenomena that are likely responsible for the evolution of renal disease in rabbits.

Late onset of renal dysfunction in survivors of bone marrow transplantation

Between 1980 and 1986, 44 children with acute lymphoblastic leukemia (ALL) or Stage IV neuroblastoma (NB) underwent allogeneic or autologous bone marrow transplantation (BMT). Twenty-nine of these patients were alive and in remission 3 months post BMT and were evaluable for this analysis of whom eleven have developed renal dysfunction. Six of 17 (35%) evaluable ALL patients developed renal dysfunction (3.5 to 6 months post BMT). This group was transplanted for CALLA positive ALL and received an autologous transplant. Preparation included tenopiside (VM 26) cytosine arabinoside, and cyclophosphamide followed by total body irradiation (TBI). One patient received 850 cGy in a single fraction, while all other patients received fractionated TBI (1200-1400 cGy in 6-8 fractions over 3-4 days). Five of 7 (71%) evaluable patients who received a BMT for NB have developed late renal problems (4-7 months after BMT). The preparation for NB patients included VM 26, cis-platinum, melphalan, cyclophosphamide, and fractionated TBI (1200-1296 cGy). All seven NB patients had received cis-platinum as induction treatment prior to transplantation. All patients presented with anemia, hematuria, and elevations of BUN and creatinine. Two patients underwent renal biopsies which were consistent with radiation nephropathy or hemolytic uremic syndrome. In conclusion, a high incidence of renal dysfunction has occurred 3 to 7 months after BMT for children with NB and ALL. The clinical and laboratory features are consistent with either acute radiation nephropathy or hemolytic-uremic syndrome. These patients were prepared for BMT with multiple chemotherapeutic agents as well as TBI. The relatively young age of these patients and conditioning with intensive multi-agent chemotherapy may decrease the tolerance of the kidney to radiation injury.

Hypomagnesemia, renal dysfunction, and Raynaud's phenomenon in patients treated with cisplatin, vinblastine, and bleomycin

Thirty men with metastatic germ cell cancer were treated with cisplatin (20 mg/m2 administered intravenously, days 1-5), vinblastine, and bleomycin at 3- to 4-week intervals for four to six courses. There was a sequential fall in serum magnesium (P less than 0.001) with each course of therapy: 26 of the 30 patients (87%) became hypomagnesemic, and the median magnesium nadir was 1.1 meq/l. No acute clinical effects of the hypomagnesemia were observed. The mean creatinine clearance declined from 115 ml/minute before therapy to 65 ml/minute, and the mean serum creatinine rose from 0.9 mg/dl to 1.6 mg/dl after six courses of therapy. With a minimum follow-up of 36 months, 13 of the patients (43%) have clinical evidence of Raynaud's phenomenon. Severity of prior hypomagnesemia predicted an increased risk of Raynaud's phenomenon. Renal dysfunction, hypomagnesemia, and Raynaud's phenomenon are common chronic toxicities of vinblastine, bleomycin, and cisplatin therapy.

Adult nephroblastoma with glomerular intracapillary deposits of IgM in the contralateral kidney

A 43-year-old man who presented with hematuria had a nephroblastoma in the right kidney. After nephrectomy the patient was treated with irradiation and chemotherapy. Despite the development of pulmonary metastases he remained reasonably well for several years. He died of metastatic disease 8 years after presentation. Histological study of the contralateral kidney at autopsy revealed intracapillary glomerular deposits of IgM.

Unilateral radiation nephropathy--the long-term significance

Eighteen patients with gastrointestinal and retroperitoneal non-Hodgkin's lymphoma received abdominal radiotherapy as their primary treatment. Each patient received a total tumor dose of 2200 to 4500 cGy in 5 to 9 weeks to the whole or half of one kidney. Nine patients developed unilateral radiation nephropathy demonstrable on post-treatment evaluation with 99m Tc glucoheptonate blood flow, delayed static scan, and an I-131 radio-hippurate renal perfusion study. The tests were periodically repeated over periods ranging from 5 to 8 years. Six patients with nephropathy and 4 patients without nephropathy were followed 5 years or longer. The minimum nephro-pathogenic irradiation dose was 2200 cGy delivered in 59 days. The incidence of nephropathy is higher with increase in the total dose. Short term recovery in function was observed in 3 patients and long-term complete recovery was observed in one patient. Atrophic renal change was irreversible and progressive in 3 patients over a 6 to 7 year follow-up period. In this group of patients, an abnormal creatinine clearance and serum beta-2 microglobulin level was indicative of vascular damage. Elevated arterial blood pressure was seen in 5 patients. All were controlled medically, without nephrectomy. There was no other clinically significant problem resulting from the unilateral nephropathy in this group of patients.

Radiation nephritis causing nephrotic syndrome

Clinical symptoms of acute radiation nephritis with nephrotic syndrome developed in a fifty-six-year-old woman after abdominal radiation therapy for an astrocytoma of the spinal cord. The diagnosis of radiation nephritis was confirmed by renal biopsy. To our knowledge, this is the first documented case of radiation nephritis associated with nephrotic syndrome.

Renal vascular lesions after chemotherapy with vinblastine, bleomycin, and cisplatin

A 30 year old man with metastatic embryonal carcinoma became hypertensive during vinblastine, bleomycin, and cisplatin therapy. Three months after completion of therapy, accelerated hypertension occurred (blood pressure 210/140 mm Hg). Nitroprusside failed to control the hypertension, but captopril resulted in a prompt and sustained normalization of the blood pressure. The plasma renin activity was markedly elevated before therapy. Renal biopsy disclosed "onionskin" narrowing of the interlobular arteries and fibrin thrombosis of a majority of the afferent arterioles. A form of drug-induced renovascular hypertension is suggested.

Influence of dietary protein levels on survival of rats following kidney irradiation

Concern about radiation induced nephropathy results in a dose limiting constraint in some applications of radiation therapy. An understanding of the etiology of radiation therapy. An understanding of the etiology of radiation nephropathy is essential if attempts to alter the time course or extent of the pathology are to be successful. In an attempt to gain a better understanding of this disease process, and to see if it could be altered by dietary manipulation, young adult male Sprague-Dawley rats were unilaterally nephrectomized, after which the remaining kidney was exteriorized and exposed to 14 Gy of X rays. Non-irradiated control animals had their remaining kidney exteriorized for a comparable length of time. Five days after irradiation, the animals were switched from standard lab rations to isocaloric diets of differing protein content. Diets used included 4%, 20% and 50% protein and the 4% and 20% diets given in combination with 0.9% NaCl drinking water. For all the diet groups, irradiated animals had median survival times shorter than their corresponding non-irradiated controls. Within the irradiated groups, the ranking of the median survival times was: 4% + 0.9% NaCl greater than 4% greater than 20% + 0.9% NaCl = 20% greater than 50%. The differences in survival among the irradiated groups were significant at the 0.01 level. These data indicate that kidney response to irradiation can be altered by manipulation of dietary protein levels. Such information may have clinical application.

Cancer and the kidney: complications of neoplasms

Various renal complications occur during the course of neoplastic disease. The therapeutic and prognostic implications differ according to the reversibility of both the underlying malignancy and the superimposed complications in the kidney. Since the mechanisms of renal failure vary significantly in patients with different types of malignancy, it is essential to avoid generalizations about etiologic factors or likely outcomes of the disease processes. The pathophysiologic abnormalities should be determined in each patient, and the reversibility of both the neoplastic and problems assessed before therapeutic decisions are made. This often requires a team effort by the internist, oncologist, nephrologist, urologist and, most importantly, the patient.

Renal manifestations of extrarenal neoplasms

In a study of 1270 consecutive autopsies there were 314 patients with malignant neoplasms arising in sites other than the kidney and central nervous system. In over 50 per cent of these there was significant renal damage related to cancer. Renal damage was produced by direct involvement of one or both kidneys by the neoplasm or by indirect effects. The latter included ischemic damage, metabolic injury, immunologic injury, and effects of therapy directed at the malignant tumor. In patients with cancer, tumor bulk and invasion of vital organs do not always explain the clinical deterioration and cause of death. Recognition of the indirect effects of tumors on the kidney and other organ systems is essential to the understanding of the generalized host response to malignant disease.

Radiation nephritis following combined abdominal radiation and chemotherapy (bleomycin-vinblastine)

A 29-year-old man presented with acute glomerulonephritis five weeks following completion of combined chemotherapy (bleomycin-vinblastine) and abdominal radiation for testicular carcinoma. There was no evidence for a post-infectious cause or a systemic collagen disorder. The renal biopsy showed changes consistent with radiation nephritis. The combined radiation and chemotherapy may have, by additive or synergistic action, caused the early appearance of radiation nephritis.