Derivation of nephrogenic adenomas from renal tubular cells in kidney-transplant recipients

BACKGROUND

Nephrogenic adenomas are benign, tumor-like lesions within the urothelial mucosa of the urinary tract that are not uncommon in renal-transplant recipients. We investigated the origin of nephrogenic adenomas in renal-transplant recipients.

METHODS

Tissue sections were analyzed by fluorescence in situ hybridization with the use of probes for the X and Y chromosomes, by immunohistochemical methods with the use of antibodies to renal tubular antigens, and by lectin histochemical methods. Forty-six nephrogenic adenomas from 29 patients were analyzed.

RESULTS

All nephrogenic adenomas in 14 female recipients of transplants from male donors and 10 male recipients of transplants from female donors showed the same sex-chromosome status as the donor kidney, but not the same sex-chromosome status as the recipient's surrounding bladder tissue. The nephrogenic adenomas from all 6 female recipients of transplants from female donors showed female chromosomes, and those from the 16 male recipients of transplants from male donors showed male chromosomes. The presence of aquaporin 1, PAX2, and lectin-binding capacity for peanut agglutinin, Lotus tetragonolobus agglutinin, and Sophora japonica agglutinin in nephrogenic adenomas indicated an origin from renal tubular cells.

CONCLUSIONS

Nephrogenic adenomas in renal-transplant recipients are derived from tubular cells of the renal transplants and are not metaplastic proliferations of the recipient's bladder urothelium.

Chronic hepatitis B virus infection in renal transplant recipients

Although in Western Europe and North America the prevalence of chronic hepatitis B virus (HBV) infection has declined in patients awaiting renal transplantation, it remains a relevant clinical problem, mainly in patients with a long history of renal replacement therapy (RRT) who may have been infected many years ago. At the same time, a significant proportion of renal transplant recipients (RTR) is at risk for HBV infection in areas with endemic HBV. HBV infection may increase morbidity and mortality in RTR. The majority of long-term studies reported reduced patient survival compared with hepatitis B surface antigen (HBsAg)-negative RTR. The risk for morbidity and mortality of HBsAg-positive RTR transplantation is probably related to the extent of pretransplant liver disease. A thorough evaluation, including liver biopsy in many patients, is required to assess the individual HBsAg-positive patient's risk-benefit ratio. The influence of immunosuppressive therapy on HBV replication and HBV-associated complications is not well established and for clinical practice individually tailored immunosuppression is recommended in HBsAg-positive RTR. Careful screening for HBV reactivation in HBsAg-positive RTR and a regular clinical follow-up after renal transplantation (RTX) including liver sonography is required for early detection of HBV-associated complications. With the availability of new antiviral drugs, new options for pre- and posttransplant therapy might improve the prognosis of RTR with chronic HBV infection.

Capillary C4d deposition in kidney allografts: a specific marker of alloantibody-dependent graft injury

Capillary deposition of the complement split product C4d has been discussed as a marker for antibody-mediated kidney allograft rejection. The relationship between C4d staining and posttransplant alloantibody detection remains to be thoroughly investigated, however. In this study, C4d staining in peritubular capillaries (PTC) and the incidence of alloantibody formation, as detected with sensitive techniques, were evaluated among a cohort of transplant recipients who had undergone biopsies and had not been selected for a specific histologic diagnosis. One hundred thirteen biopsies, obtained from 58 cadaveric kidney transplant recipients, were tested. Serum samples obtained at the time of biopsy were evaluated by flow cytometric crossmatch (FCXM) testing and FlowPRA (One Lambda, Inc., Canoga Park, CA) analysis of anti-HLA panel reactivity. Most biopsies with C4d deposits in PTC (C4d(PTC)(+), n = 21 of 24) were associated with positive posttransplant FCXM results (T and/or B cell FCXM) and/or > or =5% FlowPRA (anti-HLA class I and/or II) reactivity. Approximately 50% of the C4d(PTC)(-) biopsies were observed to be associated with donor-specific alloantibodies. Accordingly, high specificity (93%) but low sensitivity (31%) were calculated for capillary C4d staining (with FCXM testing as the standard method). For clinical evaluation, three patient groups were defined, i.e., a group of recipients with positive C4d staining in at least one allograft biopsy (C4d(PTC)(+), n = 16) and two C4d(PTC)(-) groups, which were discriminated on the basis of posttransplant FCXM results as C4d(PTC)(-)/FCXM(+) (n = 22) and C4d(PTC)(-)/FCXM(-) (n = 20) groups. Univariate analyses revealed significant differences between these groups with respect to serum creatinine levels at 12 mo [median, 2.83 mg/dl (interquartile range, 1.93 to 4.2 mg/dl) versus 1.78 mg/dl (1.47 to 2.24 mg/dl) versus 1.59 mg/dl (1.2 to 1.71 mg/dl), P < 0.001]. Of the five immunologic graft losses, four occurred in the C4d(PTC)(+) group and one occurred in the C4d(PTC)(-)/FCXM(+) group. In a multivariate analysis, C4d positivity was observed to have an independent predictive value for inferior 12-mo graft function (P = 0.02), whereas the observed moderate difference between C4d(PTC)(-)/FCXM(+) and C4d(PTC)(-)/FCXM(-) recipients did not achieve significance. In conclusion, these data demonstrate that positive C4d staining, which is an independent predictor of kidney graft dysfunction, represents a reliable specific marker for antibody-dependent graft injury.

Acute humoral renal allograft rejection

In kidney transplantation, it is well established that donor-specific antibodies can cause substantial graft injury. Hyperacute rejection, now virtually eliminated by routine pretransplant cytotoxic crossmatch testing, represents the prototype of humoral rejection. However, there is now increasing evidence that alloantibody-mediated immune reactions may also cause acute rejection. Acute humoral rejection, which is frequently associated with severe graft dysfunction and immunologic graft loss, represents a particular diagnostic and therapeutic challenge. Reliable detection of antibody-mediated graft injury is required to govern the application of antihumoral therapeutic strategies. This review focuses on new approaches in the diagnosis and treatment of acute humoral rejection. Special attention is given to a novel diagnostic marker, the complement split product C4d.

C4d-positive acute humoral renal allograft rejection: effective treatment by immunoadsorption

There is increasing evidence for an important pathogenetic role of alloantibodies in acute renal allograft rejection. Acute humoral rejection (AHR) has been reported to be associated with a poor transplant survival. Although treatment modalities for cellular rejection are fairly well established, the optimal treatment for AHR remains undefined. Ten of 352 kidney allograft recipients transplanted at the authors' institution between November 1998 and September 2000 were diagnosed as having AHR, supported by severe graft dysfunction, C4d deposits in peritubular capillaries (PTC), and accumulation of granulocytes in PTC. AHR was diagnosed 18.9 +/- 17.5 d posttransplantation. All patients were subjected to immunoadsorption (IA) with protein A (median number of treatment sessions, 9; range, 3 to 17). Seven recipients with additional signs of cellular rejection (according to the Banff classification) received also antithymocyte globulin. In nine of ten patients, AHR was associated with an increase in panel reactive antibody reactivity. A pathogenetic role of alloantibodies was further supported by a positive posttransplant cytotoxic crossmatch in all tested recipients (n = 4). In nine of ten recipients, renal function recovered after initiation of anti-humoral therapy. One patient lost his graft shortly after initiation of specific therapy. Another recipient with partial reversal of AHR returned to dialysis 8 mo after transplantation. Mean serum creatinine in functioning grafts was 2.2 +/- 1.2 mg/dl after the last IA session (n = 9) and 1.5 +/- 0.5 mg/dl after a follow-up of 14.2 +/- 7.1 mo (n = 8). In conclusion, this study suggests that AHR, characterized by severe graft dysfunction, C4d staining, and peritubular granulocytes, can be effectively treated by timely IA. In the majority of patients, IA treatment can restore excellent graft function over a prolonged time period.

Endothelial C4d deposition is associated with inferior kidney allograft outcome independently of cellular rejection

BACKGROUND

Capillary deposition of complement split product C4d has been suggested to be a valuable marker for humoral rejection. In this retrospective study we evaluated the clinical impact of C4d deposition in renal allografts with special emphasis on associations between C4d staining patterns and histological features of acute rejection.

METHODS

One hundred and two allograft biopsies obtained from 61 kidney transplants (1-532 days after transplantation; median 14 days) were examined by immunohistochemistry on routine paraffin sections using a novel anti-C4d polyclonal antibody (C4dpAb).

RESULTS

Fourty-two of 102 biopsies showed endothelial C4d deposits in peritubular capillaries (PTC). Histopathological analysis revealed a significantly lower frequency of positive C4d staining in biopsies with rather than in those without acute cellular rejection defined by the Banff grading schema (P<0.01). For clinical evaluation, patients were classified according to C4d staining in allografts (C4d(PTC) positive in at least one biopsy, n=31 vs C4d(PTC) negative in all biopsies, n=30). C4d(PTC) positive patients had significantly higher serum creatinine levels than C4d negative patients. Even in the absence of morphological evidence for rejection, differences in serum creatinine levels between C4d(PTC) positive and negative recipients were significant (6 months: 2.01+/-0.75 vs 1.41+/-0.27 mg/dl; 12 months: 1.95+/-0.60 vs 1.36+/- 0.34 mg/dl; 18 months: 1.98+/-0.50 vs 1.47+/-0.31 mg/dl; P<0.05). All patients with rejection resistant to conventional therapy (n=4) were in the C4d(PTC) positive subgroup. All recipients with panel reactive antibodies (PRA) >50% (n=8) were C4d(PTC) positive.

CONCLUSIONS

Our data indicate that endothelial C4d deposition is associated with inferior graft outcome. We provide evidence that this immunohistochemical finding and its clinical impact are not associated with morphological signs of cellular rejection.

The effects of lipid-lowering agents on acute renal allograft rejection

BACKGROUND

Preliminary results from clinical trials suggest that 3-hydroxy-3-methylglutaryl co-enzyme A reductase inhibitors may help prevent acute renal allograft rejection. However, the mechanism for this putative effect of 3-hydroxy-3-methylglutaryl co-enzyme A reductase inhibitors, and whether it is independent of lipid-lowering per SE are unknown.

METHODS

Immediately after renal transplantation we randomly allocated (proportioned 2:1:2) patients to: 1) simvastatin (10 mg/day, n=53), 2) simvastatin placebo plus gemfibrozil (dose adjusted for renal function, n=36), and 3) simvastatin placebo (n=52).

RESULTS

Simvastatin, but not gemfibrozil, reduced total and low density lipoprotein cholesterol during the first 90 days posttransplant. There were no major adverse effects of therapy. However, there were no effects of treatment on acute rejection. Indeed, survival free of acute rejection at 90 days was 72% in the simvastatin group, 72% in the gemfibrozil group, and 77% in the placebo control group (P=0.771). A post hoc power analysis suggested that there was only a 7.5% chance that a true effect of simvastatin on acute rejection (versus placebo) was not detected, and a 2.5% chance that an effect of gemfibrozil on acute rejection (versus placebo) was not detected in this study.

CONCLUSION

Lipid-lowering agents may not reduce the incidence of acute renal allograft rejection. However, additional studies are needed to confirm this observation. In the mean time, many if not most renal transplant recipients should be treated with HMG-CoA reductase inhibitors starting early posttransplant to prevent cardiovascular disease complications. The results of this study suggest that starting lipid-lowering therapy immediately after renal transplantation is both safe and effective in lowering total and low density lipoprotein cholesterol.

Comparison of sequence analysis and the INNO-LiPA HBV DR line probe assay for detection of lamivudine-resistant hepatitis B virus strains in patients under various clinical conditions

A line probe assay (INNO-LiPA HBV DR) detecting drug-resistant hepatitis B virus (HBV) strains was evaluated. Results concordant with sequence analysis were obtained with 48 of 56 serum samples from HBV-infected patients undergoing lamivudine therapy. In eight cases, additional minor subpopulations could be identified by the line probe assay.

Reasons for 50% reduction in the number of organ donors within 2 years--opinion poll amongst all ICUs of a transplant centre

To detect the reasons for a massive decrease in the annual number of organ donors and as a means of evaluating the effectiveness of our information programme, a questionnaire was designed and sent to all intensive care units (ICUs) in our catchment area. We wished to obtain information about medical, organizational and capacity problems and negative occurrences that had happend during past retrievals. Although 60% of the answers we reiceved (87% feedback rate) mentioned the additional workload involved in treating an organ donor (and 88% had serious problems because of the shortage of nurses), less than 16% remembered a "lost" donor because of capacity problems. Eighty-six percent recognized our efforts to support them in any respect and were satisfied with the amount of "service" provided by the transplantation (TX) centre. About 45% remembered negative occurrences. More than 85% of all replies asked for more and continuing information related to organ donation and transplantation. We think that the key to a successful TX programme is a system of active care for the ICU staff in all peripheral hospitals; repeated mailing of updated information brochures, annual lectures about new developments, letters of thanks after each reported donor (including information on the fate of the organs), visiting donor ICU's accompanied by successfully transplanted recipients, etc.... The downwards trend of donor rates in our area clearly shows that it takes more than a stable legal situation to ensure the necessary amount of donor organs, even a very successful TX centre has to work hard to maintain a certain standard of knowledge, information and motivation amongst the staff of the peripheral hospitals. Moreover, the high turnover rate of ICU personnel requires a steady "flow of information" and cooperation between the "transplant people" and their coworkers outside to guarantee a permanent state of awareness concerning organ donation and transplantation. In fact, awareness seems to be the key issue: the activity of sending out the questionnaires was enough to raise the number of reported donors from 72 (estimated in July) to 96 (31 December 1992).

New developments in clinical immunosuppression

Over the last few years, the armamentarium of immunosuppressants has been enriched by a variety of new drugs, that have helped to further reduce the incidence of acute rejection episodes after kidney transplantation. Nevertheless the search for new compounds drugs continues, until tolerance, the ultimate goal of transplantation medicine can be achieved. Meanwhile we should appreciate that neither all drugs nor all patients are equal and tailor the immunosuppression to the patients' needs. To define patient groups who benefit most from different immunosuppressive protocols especially in regard to long term allograft and patient survival will warrant further prospective controlled trials.

Long-term evaluation of proliferative donor antigen-specific reactivity in cadaveric kidney transplant recipients

Development of donor-specific proliferative hyporeactivity has been evaluated in many studies for its usefulness in identifying transplant recipients at low risk of immunological complications. These studies often result in controversial conclusions, however. The authors claim that the discrepancy in the predictive value of mixed lymphocyte culture- (MLC) reactivity might partly be due to differences in presentation and interpretation of results. The purpose of this study is to investigate the usefulness of a normalized evaluation of antigen-specific donor-reactivity in a small number of kidney transplant recipients. This could then serve as a basis for an extended clinical study. Ten cadaveric kidney recipients were tested for proliferative reactivity to donor- and third-party antigens up to 20 months posttransplantation. Expressing donor-specific reactivity as a relation between the percentage of pretransplant responses towards donor splenocytes and the percentage of pretransplant responses towards third-party donor cells should minimize influences of e. g. uremia, current immunosuppression or infections on the evaluation of specific reactivity and thus should allow an evaluation of the donor-specificity of T-cell alloresponses independently of fluctuations in global responsiveness. Four of ten recipients acquired a state of donor-specific hyporeactivity ( < 75 % relative specific reactivity) at 20 months post-transplantation (61 +/- 12%, mean +/- SD). Six patients were classified non-hyporeactive (98 +/- 10% mean relative specific reactivity). Relative specific reactivity did not correlate with the levels of general reactivity. Three of the four hyporeactive and four of the six non-hyporeactive patients developed acute rejection. Stable graft function at 20 months posttransplantation (serum creatinine < or = 2 mg/dl) was not closely related to the reactivity status, as five of eight patients with well-functioning grafts did not develop relative specific hyporeactivity. One recipient with chronic rejection was classified hyporeactive. One non-hyporeactive patient lost his graft due to non-immunological causes. Our data suggest that post-transplant relative specific reactivity does not predict acute rejection. Downregulation of donor-specific reactivity might not be a prerequisite for stable graft function but could help identifying recipients who require less immunosuppression. This, however, remains to be established in a prospective immunosuppression-weaning study.

A case of continuous ambulatory peritoneal dialysis peritonitis with an uncommon organism and an atypical clinical course

This report describes a 46-year-old patient who experienced an atypical course of peritonitis while undergoing continuous ambulatory peritoneal dialysis (CAPD). The first sign of peritonitis was progressive impairment of ultrafiltration with increasing fluid absorption. The patient came to the center after 5 days with leg edemas and 645 leukocytes/microL in the first dialysate outflow. On the same day, the dialysate cell count decreased to 208/microL. During the following days, ultrafiltration failure persisted despite spontaneous normalization of PD-fluid leukocytes. No other clinical symptoms were observed, and the serum C-reactive protein (CRP) level remained normal. Magnetic resonance peritoneography and abdominal radiograph did not show dislocation of the catheter, a dialysate leak, or other causes of ultrafiltration failure. At day 14, fever, diarrhea, and an elevated serum CRP level occurred. Dialysate cultures taken on days 8, 11, and 14 showed growth of NEISSERIA: sicca. After initiation of antibiotic therapy with levofloxacine on day 14 ultrafiltration, clinical symptoms and serum CRP normalized within 3 days. In conclusion, Neisseria sicca should be considered as a rare cause of PD peritonitis. Our case report further illustrates the importance of ultrafiltration failure as an early and main symptom of peritoneal inflammation. The frequently used peritonitis criteria may not apply to cases of mild PD peritonitis.

Twelve months of lamivudine treatment for chronic hepatitis B virus infection in renal transplant recipients

BACKGROUND

Chronic hepatitis B virus (HBV) infection increases morbidity and mortality in renal transplant recipients (RTR). Lamivudine has shown promising results in patients with chronic hepatitis B, but experience with its use in RTR is limited.

METHODS

In a prospective, open labeled, uncontrolled trial, 19 HBsAg(+) RTR were treated with lamivudine for 12 months. HBV-serologic analysis, HBV-DNA quantitation, and HBV genome sequence analysis were performed every 3 months.

RESULTS

At baseline 16 patients were HBV DNA(+), 12 patients were HBeAg(+)/Ab (-). After 3 months HBV DNA was negative in 80% of patients. In the 3 patients with elevated liver enzymes, normal values were achieved within 12 weeks. At 12 months 4 of 8 HBeAg(+)/Ab(-) patients on treatment showed HBeAb, two of them with loss of HBeAg. Three patients developed mutations of the HBV polymerase gene associated with lamivudine resistance.

CONCLUSIONS

Lamivudine is safe and effective in HB-sAg(+) RTR, the rate of HBe-seroconversion and of lamivudine-resistance is comparable to that of nonimmunosuppressed patients.

Monitoring the virus load can predict the emergence of drug-resistant hepatitis B virus strains in renal transplantation patients during lamivudine therapy

The development of resistant hepatitis B virus (HBV) strains during lamivudine treatment has been described repeatedly. To investigate whether the development of such resistant HBV strains can be predicted in an early phase of therapy, the HBV loads of 11 renal transplantation patients were screened at 3-month intervals by a quantitative HBV polymerase chain reaction (PCR) assay. Lamivudine resistance was detected by sequence analysis. Five patients developed resistance to lamivudine in the 12-15-month follow-up period. In all of them, a virus load of 1x103 HBV DNA copies still was detectable after 3 months of therapy. This was statistically significantly different from those patients who did not develop lamivudine resistance within the observation period, all of whom had no HBV DNA detectable after 3 months of treatment (P=.0022). Thus, virus load testing by use of a sensitive PCR assay allows the early prediction of the emergence of lamivudine-resistant HBV strains.

Beneficial effects of atorvastatin in the treatment of hyperlipidemia after renal transplantation

Despite the availability of various lipid lowering drugs, the treatment of hyperlipidemia, one of the most important risk factors for morbidity and mortality after organ transplantation, remains a therapeutic challenge. We investigated the safety and efficacy of a new HMG-CoA reductase inhibitor, atorvastatin, in renal transplant patients whose serum lipids were insufficiently controlled by diet and treatment with other lipid lowering drugs. Twenty-four patients (14 males/10 females; mean age 51.2 +/- 2.3 years) were converted to low dose atorvastatin (10 mg/day) at a mean of 67.7 +/- 8.6 months after renal transplantation and prospectively followed for 3 months after initiation of the study drug. HDL, LDL, and total cholesterol, triglycerides, serum creatinine and CPK levels were evaluated pre (-3, -1, 0 months) and post conversion (+1, +3 months). In the eighteen patients who completed the study, low dose atorvastatin therapy led to a significant reduction in total cholesterol (304.6 +/- 13.2 vs. 247.6 +/- 12.0 mg/dl; p = 0.007) and LDL cholesterol (191.9 +/- 9.0 vs. 141.8 +/- 14.7 mg/dl; p < 0.0001) and a modest reduction in serum triglyceride levels at three months after conversion. We conclude that low dose atorvastatin (10 mg/day) can be successfully used and appears to be safe in the treatment of posttransplant hyperlipidemia. Its long-term effects on patient morbidity and mortality as well as graft survival should be investigated in larger and more prolonged prospective trials.

Role of humoral immune reactions as target for antirejection therapy in recipients of a spousal-donor kidney graft

Excellent graft outcome has been reported for spousal-donor kidney transplantation. In husband-to-wife transplantation, however, a tendency toward inferior graft survival has been described for recipients who were previously pregnant. In our series of spousal-kidney transplantations (nine transplantations; three female recipients), actual graft survival is 100% (median observation time, 339 days). Five patients experienced early allograft rejection. In four transplant recipients, rejection was easily reversible by conventional antirejection therapy. In a multiparous recipient, however, mild interstitial allograft rejection associated with early graft dysfunction was resistant to anticellular treatment (antilymphocyte antibody, tacrolimus rescue therapy). The particular finding of polymorphonuclear neutrophils in peritubular capillaries and the finding of diffuse capillary deposits of the complement split product, C4d, in a posttransplantation biopsy specimen suggested a role of antibody-mediated graft injury. Retrospective flow cytometry cross-matching showed the presence of preformed immunoglobulin G (IgG) antibodies to HLA class I antigens that were not detectable by pretransplantation lymphocytotoxic cross-match testing or screening for panel reactive antibodies. After transplantation, however, complement-fixing antibodies, also presumably triggered by reexposure to spousal-donor HLA antigens, could be detected in the patient's serum. These findings suggested antibody-mediated allograft rejection and led to the initiation of immunoadsorption therapy (14 sessions) with staphylococcal protein A. Selective removal of recipient IgG resulted in complete reversal of graft dysfunction. Our findings suggest that in husband-to-wife transplantation, donor-specific antibodies, presumably triggered by previous pregnancies, might occasionally induce sustained allograft dysfunction. Thus, in this particular setting, a detailed immunologic and histopathologic work-up regarding antibody-mediated allograft dysfunction is warranted because immunoadsorption may be a highly effective treatment modality.

Vasoactive substances in renal transplantation

During and after transplantation the kidney experiences a variety of insults that result in functional impairment and structural damage. These changes are mediated or influenced by hormones, cytokines, enzymes and growth factors, which are excreted by endothelial, graft parenchymal as well as by graft infiltrating cells. This review evaluates the pathophysiological role of vasoactive substances (for example, the vasoconstrictors angiotensin II and endothelin, as well as vasodilators such as nitric oxide, adrenomedullin and atrial natriuretic peptide) in kidney transplantation and summarizes recent reports that indicate that targeting vasoactive substances may represent effective therapeutic strategies for the achievement of long-term allograft survival.

Basal calcitonin levels and the response to pentagastrin stimulation in patients after kidney transplantation or on chronic hemodialysis as indicators of medullary carcinoma

Plasma concentrations of calcitonin (hCT) were determined in 150 patients with chronic renal failure on chronic hemodialysis therapy (CHD) and in 800 patients after successful kidney transplantation (KT). Basal hCT concentrations exceeded 10 pg/mL in 44 of 150 patients (29%) with CHD and in 48 of 800 (6%) in patients with KT. Among these patients with elevated basal hCT, pentagastrin-stimulated concentrations of hCT exceeded 100 pg/mL in 4 patients with CHD and in 7 with KT. Thyroidectomy was performed in 8 patients (5 with KT, 3 with CHD) revealing the presence of medullary thyroid carcinoma (MTC) (n = 2) or of C-cell hyperplasia (n = 6). Two patients with C-cell hyperplasia had the neoplastic form of this disorder. One patient with MTC and 1 with C-cell hyperplasia also presented a papillary microcarcinoma. Stimulated concentrations of hCT were only moderately elevated in the remaining 3 patients and follow-up rather than surgery was deemed appropriate due to their concomitant severe medical problems. In conclusion, basal concentrations of hCT higher than 10 pg/mL are more common in patients with CHD (29%) and after successful KT (6%) than previously described in patients with thyroid nodular disease (3%). In spite of various additional factors complicating the interpretation of elevated hCT in CHD, pentagastrin-stimulated values above 100 pg/mL must be considered to indicate the presence of C-cell hyperplasia and/or of medullary thyroid carcinoma. Although thyroidectomy would theoretically be the therapy of choice, the potential benefit of the operation must be seen in the context of the patient's general condition.

Smoking as a risk factor for end-stage renal failure in men with primary renal disease

BACKGROUND

It is not known whether smoking increases the risk of end-stage renal failure (ESRF) in patients with primary renal disease.

METHODS

We performed a retrospective multicenter case-control study including 582 patients from nine centers in Germany, Italy and Austria. The diseases investigated were IgA glomerulonephritis (IgA-GN) as a model of inflammatory renal disease and autosomal dominant polycystic kidney disease (ADPKD) as a model of non-inflammatory renal disease. Cases were patients who had progressed to ESRF and controls were patients who were not in ESRF, that is, whose serum-creatinine failed to progress to >3 mg/dl during the observation period and who did not require renal replacement therapy. Matching for renal disease (IgA-GN, ADPKD), gender, age at renal death and region of residence resulted in 102 individually matched pairs (IgA-GN N = 54, ADPKD N = 48). Multiple conditional logistic regression was used to estimate adjusted odds ratios for independent tobacco effects.

RESULTS

In men (matched pairs: IgA-GN N = 44, ADPKD N = 28), a significant dose-dependent increase of the risk to progress to ESRF was found (non-adjusted). The baseline risk was defined as <5 pack-years (PY): (i) 5 to 15 PY, odds ratio 3.5 (95% CI 1.3 to 9.6), P = 0.017; (ii) >15 PY = 5.8 (2.0 to 17), P = 0.001. Systolic blood pressure, ACE inhibitor treatment and age at diagnosis emerged as potential confounders. After adjustment, the risk for ESRF in men with >5 PY was highly increased for patients without ACE inhibitor treatment [10.1 (2.3 to 45), P = 0.002] but not with ACE inhibitor treatment [1.4 (0.3 to 7.1), P = 0.65].

CONCLUSION

Smoking increases the risk of ESRF in men with inflammatory and non-inflammatory renal disease.