Stem cells

Stem Cells Research in Renal Failure


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The inadequacy of current treatment modalities and insufficiency of donor organs for cadaveric transplantation have driven a search for

improved methods of

dealing with renal failure. The rising concept of cell-based

therapeutics has provided a

framework

around which new approaches are being generated, and its combination with advances in stem cell research stands to bring both fields to clinical fruition. This budding partnership is presently in its very early stages, but an examination of the cell-based

therapies currently under development clearly shows the magnitude of the role that stem cells will ultimately play. The issue over reports of unexpected plasticity in adult stem cell differentiation remains a focus of debate, and

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evidence for bone marrow-derived stem cell contributions to renal repair has been challenged.

The search for adult renal stem cells, which could have a considerable impact on much of the work discussed here, appears to be narrowing. The use of embryonic tissue in research continues to provide valuable insights but will be the subject of intense societal scrutiny and debate before it reaches the stage of clinical application. Embryonic stem (ES) cells, with their ability to

generate all, or nearly all, of the cell types in the adult body and a possible source of cells genetically identical to the donor, hold great promise but face ethical and political hurdles for human use. Immunoisolation of heterologous cells by encapsulation creates opportunities for their safe use as a component of implanted or ex vivo devices.

According to a published article, Stem Cell Approaches for the Treatment of Renal Failure, “the research team led by the University of Tokyo has succeeded in

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curing renal failure in rats by transplanting somatic stem cells of kidneys from healthy rats”.

The team announced the results of their research in the June 20 issue of a U.S. science magazine, "Journal of Cell Biology."

Somatic stem cells are a type of cell in an organ that can multiply and develop into a variety of other cells of that specific organ. Such cells cannot, however, transform into cells of other organs.

Experts have expressed hope that the method can be applied to cure renal failure in humans, noting that human kidneys have similar somatic stem cells.

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"It's been confirmed that somatic stem cells in kidneys are capable of not only creating new cells but also restoring damaged organs. We may be able to develop drugs aimed at (activating) somatic stem cells," said University of Tokyo Associate Prof. Keiichi Hishikawa, a member of the research team.

The research team has identified the gene of somatic stem cells in rat kidneys, and confirmed that such cells exist only in parts of rat kidneys called stroma. The team has also discovered that somatic stem cells in kidneys are capable of developing into blood vessels and renal tubules.

In the experiment, the team transplanted 10,000 kidney somatic stem cells into the ailing kidney of each laboratory rat with renal failure.

Blood tests conducted on the rats seven days later found that their kidney functions had

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returned to normal.

Researchers said they believe that the transplanted somatic stem cells restored the damaged kidney cells, noting that the number of somatic stem cells in the rats had decreased to about 30 percent of that in healthy rats' kidneys.

The research team also found somatic stem cells in human kidneys extracted from kidney disease sufferers after examining the organs with the consent of the patients and the University of Tokyo Hospital's ethics committee.

The researchers are poised to study how to multiply somatic stem cells extracted from human kidneys in a bid to develop a method for returning artificially multiplied cells back to the patients' kidneys. It will also study medication aimed at

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activating genes that cause somatic stem cells to restore damaged kidney cells.

As of the end of 2003, about 237,000 patients with chronic renal failure were regularly undergoing artificial dialysis. (Mainichi)

There is another recent study about the subject managed in Brazil.

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Bone marrow is classically known to be the site of hematopoiesis, thus "bone marrow transplant" has been successfully used for decades as a means of treating various hematological malignancies in which the recipient hematopoietic compartment is replaced by donor-derived stem cells. More recent investigations have demonstrated that several progenitor cells exist within bone marrow that are capable of differentiating into other tissues, for example cardiac tissue. In fact, clinical trials have been conducted demonstrating beneficial effects of bone marrow infusion in cardiac patients. It is believed that injured tissue, whether neural tissue after a stroke, or injured cardiac tissue, has the ability to selectively attract bone marrow stem cells, perhaps to induce regeneration. While numerous studies have demonstrated bone marrow having therapeutic effect in conditions ranging from liver failure, to peripheral artery disease, the possibility of using bone marrow stem cells in kidney failure has been relatively understudied.

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A recent paper (Alexandre et al. Lineage-Negative Bone Marrow Cells Protect against Chronic Renal Failure. Stem Cells 2008 Dec 18) addressed this question.

Researchers used a rat model of chronic renal failure in which one kidney is excised so as to increase the load of the remaining kidney, thus causing a chronic deterioration that resembles the clinical situation of renal failure.

The rats were divided into 4 groups.

Group 1 were sham operated and both kidneys left in place.

Group 2 had a kidney removed but were not administered cells.

Group 3 were administered 2 million lineage negative bone marrow cells on day 15 after one of the kidneys was removed.

Group 4 were administered 2 million lineage negative bone marrow cells on days 15, 30, and 45 after one of the kidneys was removed.

They found:

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- Expression of inflammatory cytokines was reduced on day 16 in the kidneys of rats recieving stem cells as compared to rats that were nephrectomized but did not recieve cells.

- On day 60 rats recieving stem cells had decreased proteinuria, glomerulosclerosis, anemia, renal infiltration of immune cells and protein expression of monocyte chemoattractant protein-1, as well as decreased interstitial area.

- Injured rats had higher numbers of proliferating cells in the kidney, whereas rats recieving stem cells had less.

- Protein expression of the cyclin-dependent kinase inhibitor p21 and of vascular endothelial growth factor increased after nephrectomy and decreased after Lin(-) cell treatment.

- On day 120, renal function (inulin clearance) was improved in the rats which were administered bone marrow cells compared to controls.

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This study supports the possibility of using bone marrow cells for various aspects of kidney failure. Other studies have demonstrated that administered stem cells promote kidney repair by secretion of IGF-1, it would be interesting to see if the lineage negative cells used in this study make more of this cytokine.

Stem cells have generated considerable interest recently in the scientific, clinical, and public arenas. The third book in the Stem Cell Repair and Regeneration series offers contributions from numerous areas bridging medicine and the life sciences. Significant research activities in the tissue engineering or regenerative medicine (the term recently used) field started in the 1970s, and there is currently great excitement over the possibility of replacing damaged body parts through regenerative medicine. Potential strategies to replace, repair and restore the function of damaged tissues or organs include stem cell transplantation, transplantation of tissues engineered in the laboratory, and the induction of regeneration by the body's own cells. It is believed that novel cellular therapeutics

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outperform any medical device, recombinant protein or chemical compound. This volume explores novel stem cell therapeutic strategies for myriad diseases, including renal failure, retinal disease and myocardial infarction.

Recovery of acute renal failure and nephrotic syndrome following autologous stem cell transplantation for primary (AL) amyloidosis

Primary AL amyloidosis is a plasma cell dyscrasia characterized by the deposition of monoclonal immunoglobulin light-chain protein. The latter forms insoluble fibrils with ß-pleated sheet configuration within a variety of tissues, resulting in severe organ dysfunction and poor outcome. In patients with

primary AL amyloidosis,

cyclic treatment with melphalan and

prednisone improves by 2-

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fold median survival from 8 to 18 months [1]. However, this regimen affords no benefit on renal survival, while kidney involvement occurs in 48–82% of patients [1,2]. The most common renal manifestations include nephrotic-range proteinuria and progressive renal failure that ultimately require dialysis support in one-third of all cases [3]. To break down the production of the amyloidogenic immunoglobulin by the underlying

B-cell clone and stop tissue deposition, dose-intensive melphalan with autologous blood stem cell support is currently under evaluation in primary AL amyloidosis [4].

We report the case of a 50-year-old woman with primary AL amyloidosis who experienced a complete recovery of both nephrotic syndrome

and protracted anuric renal failure after high-dose melphalan and autologous blood stem cell

The patient was referred to our centre for lower limb oedema, a 5 kg weight loss, and syncope the day before admission. On physical examination, supine blood pressure was 112/74 mmHg

dropping to 98/75 mmHg, while standing, without an increase in pulse rate. Non-infiltrative purpura of abdominal skin and hepatomegaly were also

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found. During hospitalization, she experienced

bloody diarrhoea.

Initially, her serum creatinine was 89 µmol/l. On serum protein electrophoresis, albumin was 19 g/l and a 3 g/l monoclonal component (M-protein) was detected. Immunofixation characterized the peak as a monoclonal IgA lambda. The 24-h urinary protein excretion reached 6.4 g, consisting of albumin (56%), the M-component (20%) and free lambda light-chains. Serum calcium concentration was 1.9 mmol/l, blood haemoglobin was 14 g/dl. Bone marrow aspiration failed to demonstrate excess of abnormal plasmocytes and skeletal X-rays were normal.

Renal biopsy disclosed glomerular amyloidosis with positive deposits for Congo red staining in the mesangium and along the capillary walls. There was no deposit along the tubules nor in blood vessel walls. By immunofluorescence study, intense glomerular staining was found with an anti- serum. Staging of AL amyloidosis demonstrated peripheral neuropathy and included tilt-test that confirmed autonomic failure. Biopsies showed involvement of both upper and lower gastrointestinal tract by AL amyloidosis. Echocardiography demonstrated left ventricular

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hypertrophy (septum wall thickness, 11 mm) and diastolic dysfunction. One month after admission, an ischaemic stroke related to paroxystic atrial fibrillation occurred. Anticoagulation was started and neurological deficit resolved within a few days. A diagnosis of primary AL amyloidosis was made with renal, cardiac, neurological and digestive involvement.

After counseling, the patient decided for high-dose melphalan and autologous peripheral blood SCT. Granulocyte colony stimulating factor was initiated for stem cell mobilization at 10 µg/kg/day for 5 days. Leukapheresis was then successfully performed, collecting 7.25 x 106/kg CD34+ progenitor cells. Two weeks later, the patient

underwent conditioning with high-dose melphalan (200 mg/m2) followed by autologous stem cell infusion 2 days later (referred to as day 0). On day 8, while related treatment toxicities were

limited to mild leucopenia (700 leukocytes/mm3) and grade III mucositis, the patient developed rapidly progressive multi-organ failure including acute respiratory distress syndrome and anuria,

related to a septic shock (Figure 1). Treatment associated positive end expiratory pressure mechanical ventilation, i.v. pressor support (epinephrine), continuous veno-venous

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haemodiafiltration and broad-spectrum antibiotherapy. No causative microorganism was isolated. Epinephrine was required until day 14. On day 22, she was extubated and haemodiafiltration was switched to periodic haemodialysis.

From day 49, she recovered from renal failure and serum creatinine dropped to 80 µmol/l on day 58. The nephrotic syndrome persisted: proteinuria was 5.8 g/day while serum albumin was 17 g/l. By serum and urinary protein immunoelectrophoresis, neither the M-component nor free lambda light-chains could be detected. On day 86, serum creatinine and albumin were 70 µmol/l and 20 g/l, respectively. The patient was discharged with 5 mg of lisinopril for nephroprotection and 2 mg of acenocoumarol.

Six months after engraftment, 24-h urinary protein output was 1.25 g, without monoclonal component in serum or urine. Serum creatinine was 90 µmol/l, while assessment of glomerular

filtration rate by EDTA clearance was 33 ml/min/1.73 m2. Complete remission of the nephrotic syndrome was achieved by 15 months

post-SCT. On last follow-up, 3 years post-transplantation, serum creatinine was 103 µmol/l

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and serum albumin was 42 g/l. There was no detectable M-protein in blood or urine. Autonomic

failure and left ventricular diastolic dysfunction assessed by echocardiography stabilized. Gastrointestinal symptoms remained unchanged.

Survival remains unsatisfactory in primary AL systemic amyloidosis. Two studies have shown that combination of oral melphalan and

prednisone as compared with colchicine resulted in a significant albeit small increase in median survival from 8 to 18 months in one study [1] and from 6 to 12 in the other [2]. Autologous SCT was introduced with the assumption that eradication of the culprit clone would completely stop the production of the amyloidogenic immunoglobulin, and subsequent tissue deposits. In a recent

overview of published series, 62% of patients entered complete haematologic response following SCT [4]. However, treatment-related

mortality ranged from 21 to 39% according to the different series, thus making it necessary to select the patients eligible for transplantation [4]. Early mortality is best predicted by the extent of amyloid organ involvement. In two early trials, the 100-

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days survival rate in patients with two or fewer affected organs reached 81%, as compared with 31% in patients with three and more systems involved (P < 0.01) [5,6]. Additional prognostic

factors of mortality include cardiac amyloid deposition and a pre-SCT increase of serum creatinine level, which is also predictive of acute renal failure early post-procedure.

Our patient was a middle-aged woman with rapidly progressive multi-system amyloidosis involving kidney, heart, gastrointestinal tract and nervous system. Being aware of the prognosis of her disease and the risks of the treatment, she elected dose-intensive melphalan and blood SCT. While on aplasia she developed septic shock and multi-organ failure including anuria, and required

dialysis for 6 weeks before recovery. A complete haematological response was achieved. On mid-term, the nephrotic syndrome went on complete remission, while mild renal failure persisted and

extra-renal involvement stabilized.

The renal course deserves two comments. (i) To our knowledge, no other patient with AL renal amyloidosis necessitating dialysis support for 6 weeks eventually recovered good renal function.

Acute renal failure carries very poor prognosis in

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the patients with AL amyloidosis. In patients who necessitate dialysis support, the median survival time from the start of haemodialysis in only 8.2 months [3]. (ii) Resolution of the nephrotic syndrome was obtained following haematological remission achieved by SCT. This reinforces the relationship between the haematological and the renal responses. As shown by Dember et al. [7] renal benefits can be expected following successful SCT. Among 50 patients who survived >12 months after SCT, she pointed out that 71% of the patients achieving haematologic response met the criteria of renal response, as compared with 11% of haematologic non-responders. Also, 68% of haematologic responders maintained a creatinine clearance at 75% of the baseline value and only 8% of patients progressed to dialysis up to 4 years of follow-up. Of note, remission of nephrotic syndrome usually occurs despite

persistence of glomerular amyloid deposits [8]. In contrast, while anecdotal reports documented complete resolution of AL amyloidosis-related nephrotic syndrome and improvement of renal failure after many years of melphalan-prednisone therapy [9], Kyle et al. [1] found no difference regarding the renal response nor the need for dialysis support in a prospective trial comparing

melphalan-prednisone and colchicine.

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For our patient, despite poor prognosis factors including four-organ

systems involvement and because of a rapidly progressive course, dose-intensive therapy was the unique approach to obtain prompt

eradication of the plasmacytic clone and stop the progression of amyloid disease. This intuition is consistent with a recent randomized trial where survival of the patients did not benefit from two cycles of oral melphalan-prednisone before SCT, as compared with immediate treatment by SCT [10]. That latter approach mostly benefited to the patients with cardiac involvement, who carry the highest risk of early death. Reduction of melphalan dosing (to 140 or 100 mg/m2) may also result in a similar rate of haematologic response and improvement of organ involvement, with lower morbidity and mortality rates [4]. Such individualization of the treatment, based on a risk-

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adapted approach may extend indications of SCT to patients otherwise considered ineligible.

In sum, this report highlights how autologous SCT may apply to the patients with primary AL amyloidosis and severe multi-system

involvement. Futhermore, resolution of acute renal failure and nephrotic syndrome are achievable, with long-term stabilization of kidney dysfunction.

Conflict of interest statement. None declared.

A link to be able to watch a little bit more of stem cell research on renal failure: http://www.youtube.com/watch?v=e2thGgSJuMcBy Mariel Kalkach Aparicio

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