Kidney dysfunction after non renal solid organ transplantation

Chronic kidney disease developed after non renal solid organ transplantation in a significant issue. Evaluation of kidney function starting form a complete history and physical examination, then an accurate measurement of renal function and a urinalysis, followed by kidney imaging study should be performed prior to transplantation. Moreover, probability of reversibility of kidney dysfunction and the risk of progression to end stage renal disease should be assessed. During peri- and postoperative period hypotensive episodes should be avoided or at least minimized. Good blood pressure control (however, no guidelines for target blood pressure values for non solid organ transplants are available) as well as tight control of diabetes and hyperlipidemia should be implemented. Proteinuria, if present, should be attenuated by the use of therapeutic modalities (RAS blockade) to prevent or delay the progression of renal failure. The ability to identify CKD may allow early implementation of treatments that could arrest or delay the progression of renal damage, enable effective treatment of its complications, and reduce the risk of drug-induced nephrotoxicity. Kidney function should be monitored in nonrenal solid organ transplant recipients as an important risk factor comparable with diabetes for cardiovascular mortality and morbidity. In presence of existing nephron sparing immunosuppressive regimens, early detection of deteriorating kidney function gives the opportunity to tailor the treatment. A multidisciplinary approach for these patients including also a nephrologist should be considered.

Atypical calcineurin inhibitor-induced haemolytic uremic syndrome after liver transplantation

BACKGROUND

A case of calcineurin inhibitor (CNI)--induced haemolytic uremic syndrome (HUS) after liver transplantation leading to irreversible renal failure is described.

CASE REPORT

We present case history of 25-years old male after liver transplantation due to cryptogenic cirrhosis with prolonged worsening graft function, who developed HUS. Unsatisfactory graft function was the reason of performing numerous graft biopsies. Features of acute and chronic rejection (CR) of liver were histopathologically confirmed. Vanishing bile duct syndrome as manifestation of CR was stated and immunosuppressive regimen was intensified (tacrolimus placed cyclosporin). High blood levels of tacrolimus were maintained (approximately 20-22 ng/ml) on dose 3 mg twice a day. No clinical effect was observed. Renal failure was improving (serum creatinine was 3.3 mg/dl and eGFR was 24 ml/min/1.73 m(2)). After four months of maintaining high dose of tacrolimus patient was referred to our center in order to estimate indications for liver retransplantation. On admission severe haemolytic anaemia, thrombocytopenia and acute renal failure were detected. Atypical HUS probably related to CNI was diagnosed. Tacrolimus administration was discontinued. Blood and plasma transfusion as well as plasmapheresis were implemented. Haemolysis was limited, but renal function was not improved. Renal biopsy revealed features of irreversible nephropathy in course of thrombotic microangiopathy. Despite previously maintaining high dose of CNI, there were no signs of CNI nephrotoxicity. Patient required haemodialysis. Due to necessity of haemodialysis and worsening function of liver, patient was accepted to liver and kidney transplantation.

CONCLUSIONS

High CNI blood concentration in patient after liver transplantation can be atypical cause of HUS and leads to irreversible renal failure.

Catastrophic antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an autoimmune disease with clinical manifestations of arterial and venous thrombosis, concomitant fetal loss and the presence of antiphospholipid antibodies (APLA). This report focuses on the challenges of optimal treatment involving plasma exchange and intravenous human immunoglobulin infusions that is administered in patients with catastrophic APS (CAPS). CAPS is a rare variant of APS defined as acute failure of at least three tissues, organs or systems caused predominantly by small vessel thrombosis confirmed by histopathologic evidence. CAPS develops rapidly and leads to death in 50% of cases. We present the case of a 39-year-old male patient with APS with worsening renal function. Positive lupus anticoagulant, markedly high concentrations of anticardiolipin and anti-beta 2-glikoprotein I antibodies have been observed. According to the criteria introduced by Asherson, a catastrophic form of APS was diagnosed and the patient had been treated with low-molecular-weight heparin, glucocorticosteroids, and plasmapheresis. In order to maintain clinical improvement, the patient was given human immunoglobulins i.v. (1 g/kg body weight). After the procedure, gradual clinical improvement was observed and renal function remained stable (serum creatinine level of 1.5 mg/dl).

Calcineurin inhibitor sparing immunosuppressive regimens in kidney allograft recipients

Calcineurin inhibitors (CNI), cyclosporine and tacrolimus, have had a potent impact on the success of organ transplantation. However, the nephrotoxicity associated with CNI can cause renal dysfunction, which is an independent risk factor for graft loss and mortality after kidney transplantation (KTx). Thus, the search for an optimal immunosuppressive therapy continues to be crucial in KTx. Strategies to limit CNI exposure include CNI minimization, avoidance, and withdrawal. We conducted a literature review (PubMed, Medline) on this issue. Maximum reduction in CNI is associated with a modest improvement in renal function; however, the kidney damage is observed as long as CNIs are maintained. Avoidance of CNI is associated with high acute rejection rates. CNI withdrawal may be the optimal strategy because it reduces early immunologic graft injury after KTx, particularly when CNI withdrawal is initiated before irreversible renal damage. These strategies seem feasible with mycophenolate acid, sirolimus and induction therapy with interleukin-2 receptor antibodies as concurrent immunosuppressants.

Late conversion to everolimus complicated with necrotizing glomerulonephritis in a renal allograft recipient: case report

Conversion from calcineurin inhibitors (CNI) to proliferation signal inhibitors (PSI), such as sirolimus or everolimus (EV), may improve the course of chronic allograft nephropathy. Herein we have presented a case of a kidney recipient with chronic cyclosporine (CsA) nephrotoxicity who was converted from CsA to EV at 5.5 years posttransplantation. There were no significant changes in immunofluorescence (IFL) or in electron microscopy (EM) in the preconversion biopsy. Two months after conversion, proteinuria and creatinine increased. The biopsy showed focal, segmental necrosis of the glomerular tuft with the formation of segmental cellular crescents and increased endocapillary cellularity. IFL showed granular deposits of IgG, IgM, and C3 mostly along the capillary walls; it was negative for C4d. EM revealed electron-dense deposits within the glomerular basement membrane (GBM) and in the subendothelial region with significant reduction in the capillary lumina due to GBM reduplication and widening of lamina rara interna with the formation of fibrillary structures therein: focal, segmental glomerulosclerosis. EV was withdrawn and we administered tacrolimus and steroid pulses with improvement. Five months after the withdrawal of EV, a third graft biopsy showed remission of the necrotizing glomerulonephritis. However, the patient demanded dialysis at 17 months after conversion to EV. We concluded that necrotizing glomerulonephritis with immune complex deposition in a renal allograft was possibly induced by late conversion from CNI to EV. Reconversion to CNI may be recommended in cases of PSI-associated posttransplantation glomerulonephritis but the long-term prognosis is uncertain.

Transplant glomerulopathy: clinical and pathological correlations

OBJECTIVE

Chronic transplant glomerulopathy (TG) is one of the leading causes of severe posttransplantation proteinuria and graft loss. Our current knowledge about risk factors for the development of TG, as well as factors that affect its dynamics and prognosis, is poor. We sought to describe the pathological and clinical risk factors and correlations of TG as well as parameters that influenced the survival of grafts with that pathology.

MATERIALS AND METHODS

We retrospectively reevaluated 86 kidney transplant cases with TG that have been recognized on the basis of an indication biopsy since 1997. All TG as well as all pre-TG (previous) biopsies were characterized for the presence of C4d deposits in the graft.

RESULTS

Younger recipient age and minimal immunosuppression due to drug withdrawal or suboptimal drug doses/blood levels within 3 to 6 months preceding the biopsy were associated with C4d deposition in peritubular capillaries (PTC; P = .0053 and P = .0365, respectively). Diffuse PTC-itis (P = .029, RR [95% confidence interval] = 3.349 [1.131-9.919]) and total interstitial inflammation score (P = .015, RR [95% confidence interval] = 9.662 [1.784-52.329]) were observed to show a negative impact on graft survival. C4d deposition in PTC and glomeruli, the level of pretransplantation sensitization, episodes of acute rejection, and C4d in previous (pre-TG) biopsies did not influence the survival of grafts with TG.

CONCLUSIONS

Younger recipient age and minimal immunosuppression were associated with C4d positivity in grafts with TG. The survival of kidney grafts with TG was significantly affected by the magnitude of inflammation in the interstitium and PTC, but not by C4d positivity in PTC and glomeruli.

Long term medical and economical benefit of machine perfusion (MP) kidney storage in comparison to cold storage (CS)

BACKGROUND

Despite documented positive effect of MachinePerfusion (MP) on long-term kidneys-graft function its wide use is restricted due to higher costs. The aim of this study was to analyze the difference in costs of kidney transplantation in patients who received organ stored in ColdStorage (CS) vs those who received kidneys stored with MP.

MATERIAL/METHODS

Analysis was done on kidney transplantations performed between 1994-1999 in 415 patients.. Kidneys were not randomized to MP or to CS: 188 kidneys were stored in CS, 227-in MP. Recipients didn't differ in regard to the age, sex, PRA, HLA mismatch, and immunosupression.The costs of organ procurement,transportation,surgical and anesthetic procedures, episodes of acute rejection were similar for both group of patients and were not included into the analysis. Costs of first month post-transplantation included: the cost of MP, post-transplantation hemodialysis, costs of hospitalization.Analysis of costs difference in between two groups of patients during follow-up included the costs of immunosupression and the monthly cost of dialysis. Statistical analysis was done using linear regression model.

RESULTS

Long graft survival was 68,2% in MP group vs.54,2% in CS group (p=0.02) Return to dialysis treatment was 20% in MP group vs.36% in CS group (p=0.01).Since 2 month post-transplant, mean cost of treatment for one patient was higher of 59,7 USD in CS group vs. MP group (p<0.001)in each month. Costs of investments on MP were equalized in 16 month post-transplantation.

CONCLUSIONS

Despite higher costs of MP use in the first month post transplantation, it is money-saving method of kidneys preservation and its cost of use, are equalized after 16 months post transplantation.

Chlamydia pneumoniae infection in patients after kidney transplantation treated with spiramycin

INTRODUCTION

Previous research has pointed to a role of Chlamydia pneumoniae infection in the development of chronic renal allograft dysfunction, chronic liver rejection, and vasculopathy in the transplanted heart. The aim of this study was to evaluate the presence of C. pneumoniae prior to and after kidney transplantation as well as to determine the role of spiramycin therapy among kidney transplant recipients.

MATERIALS AND METHODS

The study group consisted of 50 patients (25 pairs) who received kidney transplants from cadaveric donors. One of the 2 kidneys from a donor was transplanted to a patient randomized to spiramycin (2 x 3 million U/d orally for 3 months; group S) and the other to a patient assigned as control (group C). Markers of infection were assessed on day 1 posttransplantation and 3 months later (average, 94 days). All 50 patients were examined for the presence of bacterial DNA in peripheral blood leukocytes using real-time polymerase chain reaction (PCR) and for titers of serum anti C. pneumoniae immunoglobulin (IgG) and IgA antibodies using microimmunofluorescence (MIF). C. pneumoniae infection was diagnosed by the presence of C. pneumoniae DNA in peripheral blood leukocytes or positive antibodies of both classes.

RESULTS

C. pneumoniae infection was initially diagnosed in 14 patients among group S and 8 patients among group C (P = not significant [ns]) and after 3 months in 12 and 9 patients, respectively (P = ns). Conversion from positive to negative C. pneumoniae status occured in 7 patients among group S and 1 patient among group C (P = .04). Conversion from negative to positive C. pneumoniae status occured in 5 patients from group S and 2 patients from group C (P = ns).

CONCLUSIONS

These results suggest a possible role for spiramycin treatment of C pneumoniae infection in kidney allograft recipients. C. pneumoniae infection diagnosis and treatment should be considered to be routine for every patient awaiting transplantation.

The Comparison of the Podocyte Expression of Synaptopodin, CR1 and Neprilysin in Human Glomerulonephritis: Could the Expression of CR1 be Clinically Relevant?

Podocytes are considered as the most important cells that determine loss of structure and function of the glomerular filter. We compared the expression of three podocyte markers, i.e.: synaptopodin (SYN), CR1 and neprilysin (NEP) in 107 patients with different forms of glomerulonephritis (GN) and 5 normal kidneys (NK). A quantitative immunohistochemistry was applied to evaluate the expression of podocyte proteins. The results were related with serum creatinine (Scr), estimated glomerular filtration rate (eGFR) and urinary protein. We observed the reduction in the podocyte expression of NEP, SYN and CR1 in proliferative and non-proliferative forms of GN. Interestingly, in mesangial proliferative GN (MesPGN), the expression of SYN and CR1 was lower in IgA-MesPGN than in non-IgA-MesPGN (p<0.005 and p<0.02, respectively). In all the patients, the expression of NEP and SYN was positively related (r=0.53, p=0.02) as that of NEP and CR1 (r=0.39, p=0.04). Yet, clinical correlations with Scr (r=-0.33, p=0.03) and eGFR (r=0.26, p=0.05) were obtained only with respect to CR1. In conclusion, SYN, CR1 and NEP may be used as markers of podocyte loss in patients with GN. However, in agreement with previous studies, the clinical relevance draws a special attention to the expression of CR1.

The early and long term function and survival of kidney allografts stored before transplantation by hypothermic pulsatile perfusion. A prospective randomized study

BACKGROUND

A prospective evaluation of the influence of methods of kidney storage prior to transplantation on long-term graft function has not been shown so far. A retrospective study undertaken in 415 patients in our department showed the benefit of machine perfusion (MP) on long-term results. The aim of the present study was to assess prospectively the long term function and survival of paired kidney allografts retrieved from the same donor, comparing the influence of cold storage (CS) and MP.

MATERIAL/METHODS

74 recipients included in the study received kidneys from 37 cadaveric donors. Kidneys were randomized to storage by CS or MP. There were no significant differences between the groups as to age, gender, duration of ESRD treatment, PRA titres, HLA compatibility and immunosuppressive regimens.

RESULTS

At 10 years follow-up recipients of CS-stored kidneys returned to dialysis treatment twice as frequently as recipients of MP-stored kidneys (50% vs. 25%, p=0.02).

CONCLUSIONS

Kidney storage by MP improves graft survival and reduces the number of patients who return to dialysis treatment at long-term post-transplant.

Influence of preservation method on histopathological lesions of kidney allografts

BACKGROUND

Cold storage (CS) of cadaveric kidneys procured from hemodynamically stable donors for less than 24 hours is a safe procedure. Some papers indicate that continuous pulsatile machine perfusion (MP) allows for extension of preservation times, permits a wider use of kidneys damaged by preagonal ischemia, results in superior immediate function rate as compared to CS and improves long-term graft survival. The aim of the study was to evaluate the influence of kidney preservation method prior to transplantation on the characteristics of histopathological lesions of allografts at long-term post transplantation.

MATERIAL/METHODS

The study group consisted of 274 patients who received a cadaveric kidney allograft between 1994 and 1999. Altogether 553 biopsy specimens were obtained from this group of patients between 1994 and 2004 and graded according to Banff 2005 criteria.Two groups were identified: CS - recipients of kidneys stored in simple hypothermia (n=114) and MP - recipients of kidneys stored by machine perfusion (n=160). There were 161 cadaveric donors, 92 in the Mp group and 69 in the CS group. The 553 biopsy specimens obtained revealed the following: interstitial fibrosis and tubular atrophy - 189, chronic rejection - 19, acute rejection - 64, arteriosclerosis - 117, calcineurin inhibitor toxicity - 25, microangiopathy - 44, focal glomerulosclerosis - 82, arteriole hyalinization - 85, ATN - 241.

RESULTS

In the CS group histopathological lesions consistent with interstitial fibrosis and tubular atrophy were more frequently encountered than in the MP group (90% vs 64%, p<0.05) Also, chronic rejection was more frequent in the CS group (9% vs 3%, p<0.05). The remaining lesions encountered in biopsies did not differ significantly between the groups.

CONCLUSIONS

Kidneys preserved by cold storage are more frequently affected by chronic rejection and interstitial fibrosis.