Calcium channel blockade inhibits release of TNF alpha and improves survival in a rat model of acute pancreatitis

Tumor necrosis factor-alpha (TNF alpha) has been implicated as one of the numerous likely mediators of the systemic complications of acute pancreatitis. Recent suggestions that calcium (Ca2+) acts as a signal not only for TNF alpha release but also for TNF alpha action at distant sites led us to hypothesize that the calcium channel blocker diltiazem could inhibit TNF alpha release in acute pancreatitis, ameliorating the severity of the disease and improving overall survival. A rat model of acute pancreatitis induced by retrograde ductal infusion of bile was used for two experiments (n = 120). Experiment 1 was designed to determine the effects of calcium channel blockade using diltiazem on the severity of pancreatitis as measured by changes in biochemistry, pathology, and serum TNF alpha levels. In experiment 2, effects of calcium channel blockade on animal survival were measured over 72 h. Calcium channel blockade was associated with a significant reduction in serum TNF alpha levels as well as amelioration of pancreatitis by biochemical and pathological criteria. Overall survival from bile-induced pancreatitis was dramatically improved in rats pretreated with diltiazem (80%) compared to untreated animals (40%). Our data suggest that calcium channel blockade is associated with TNF alpha inhibition and improved outcome in a rat model of acute pancreatitis.

The correlation of Banff scoring with reversibility of first and recurrent rejection episodes

Recurrent acute rejection remains a significant problem for recipients of renal allografts, with a large proportion of patients progressing to graft loss. The newly introduced Banff schema was used to determine whether the histologic pattern of acute rejection (severity and renal compartment scoring) could discriminate recurring from nonrecurring rejections and to examine whether objective rejection scoring had predictive value for rejection reversal and outcome. A total of 67 biopsies obtained from 50 patients with acute rejection were examined for the occurrence of recurrent allograft rejection. All patients were maintained on a cyclosporine-based triple immunosuppressive protocol and had biopsy-proven acute rejection without chronic changes. Rejection recurred in 13 patients (26%), of whom 4 further developed a third rejection. The majority of the patients developed this first rejection within 2 months posttransplantation. Demographics, prebiopsy renal function, immunosuppression, and peak serum creatinine level at the time of biopsy were similar in patients with multiple and single rejection. Peak levels of reactivity to panel of lymphocytes seemed higher in the group of patients with recurrent rejection, whereas HLA matching was similar for all patients. Banff scores for acute rejection did not discriminate patients at risk of rejection recurrence who had lower vascular (0.6 vs. 1.2), tubular (0.6 vs. 1.1), and lower cumulative SUM (3.0 vs. 4.5) scores on their first rejection when compared with patients with one rejection. Histological scoring was, however, significantly different when first and third episodes were compared in the same patient, indicating increased rejection severity with recurrence. Moreover, the rate of reversal of recurrent rejection by anti-lymphocyte therapy was significantly less than that of first rejection (P<0.05). In conclusion, these data demonstrate that Banff scoring correlated with rejection reversal and steroid responsiveness, yet rejection recurrence was independent of histological score of the first rejection. Furthermore, Banff schema provided an objective histological correlation to the poor clinical outcome seen with recurrent rejection. The data also suggest that patients with early mild rejection continue to be at risk for recurrence and graft loss.

Intragraft angiotropic large-cell lymphoma of T cell-type in a long-term renal allograft recipient

Chronic immune suppression is a risk for the development of post-transplantation lymphoproliferative disorders, which are frequently caused by a B-cell dyscrasia. We report a unique primary presentation of the rare angiotropic lymphoma in a kidney allograft, 18 years after transplantation. The diagnosis was made by a percutaneous allograft biopsy specimen when the recipient presented with renal dysfunction and intermittent hematuria. Immunostaining of the biopsy specimen revealed a T-cell lineage of the neoplastic cells rather than the more common B-cell source. At the time of biopsy, there was no evidence of systemic dissemination of lymphoma. The intragraft lymphoma resolved completely after chemotherapy, but the patient died 6 months later as a result of an intracerebral hemorrhage. At autopsy, intravascular lymphoma was only found in the cerebral vessels. To the authors' knowledge, this is the first report of angiotropic T-cell lymphoma in a kidney allograft. A description of the clinical, pathologic, and immunohistochemical features of this case is provided, as well as reviews of previous reports of renal angiotropic lymphoma and post-transplantation T-cell lymphomas.

Anti-TNFalpha therapy improves survival and ameliorates the pathophysiologic sequelae in acute pancreatitis in the rat

BACKGROUND

Elevated levels of tumor necrosis factor-alpha (TNFalpha) have been measured in a lethal model acute pancreatitis (AP) and may contribute to the pathophysiologic sequelae of the disease.

METHODS

To determine the significance of anti-TNFalpha therapy on survival and disease manifestations in a clinically relevant model of AP, a rat model was developed using a retrograde pancreatic ductal infusion of bile. Animals were randomized to no treatment (n = 30) or treatment with anti-TNFalpha antibody 15 minutes prior to induction of AP (n = 30). Five treated and 5 untreated rats were killed at various time periods up to 72 hours to provide temporal characterization of TNFalpha activity in AP.

RESULTS

A burst Of TNFalpha activity in the serum of untreated pancreatitis animals between 1 and 3 hours after induction of the disease is prevented by pretreatment with anti-TNFalpha antibody.

CONCLUSIONS

These findings provide a plausible mechanism for the improvement in biochemical and histologic parameters as well as in overall survival in an experimental model of acute pancreatitis in the rat.

Correlation between Banff classification, acute renal rejection scores and reversal of rejection

The Banff classification of acute rejection is based on histologic grades and scores for borderline changes, glomerular, vascular, interstitial and tubular lesions. We reviewed 56 episodes of acute rejection occurring in 44 kidney allograft recipients (30 cadaveric and 14 living donor transplants), comparing Banff classification to degree of reversibility of rejection. Rejection reversal was defined as complete if serum creatinine returned < or = 25% of baseline, partial if creatinine was > 25% to < 75% of baseline, and irreversible if creatinine was > or = 75% of baseline or graft loss occurred. Eight biopsies were classified as borderline (SUM score 1.6 +/- 0.5), 14 grade I (SUM score 3.3 +/- 0.4), 19 grade II (SUM score 4.2 +/- 0.3), and 15 grade III (SUM score 8.5 +/- 0.4). SUM distinguished borderline and grade III rejections, but not grades I and II. Clinically, grade and SUM score correlated with rejection reversal. Complete reversal of rejection occurred in 93% of patients with grade I rejection, while 47% of patients with grade III had irreversible rejection. The mean SUM for complete reversal was 3.9 +/- 0.34 and was different from SUM of partial (6.0 +/- 0.86) and irreversible (8.5 +/- 0.93), P < 0.006. Meanwhile, vascular scores were similar for rejections with complete (0.9 +/- 0.2) or partial (1.0 +/- 0.4) reversal, but significantly higher in those with irreversible rejection (3.0 +/- 0.4, P < 0.000). Likewise, mean scores for tubulitis and interstitial inflammation were significantly higher for irreversible rejection. Resolution of rejection by steroids was correlated to low vascular score (steroid sensitive 0.65 +/- 0.25 vs. steroid resistant 1.42 +/- 0.18, P < 0.01), and low SUM score (steroid sensitive 3.7 +/- 0.5 vs. steroid resistant 5.22 +/- 0.43, P < 0.04). Neither scores for tubulitis nor interstitial cellular inflammation were predictive of steroid sensitivity. These data demonstrate that Banff scoring has clinical relevance in predicting rejection reversal and has implications to first-line therapy of rejection episodes.

Inhibition of TNF alpha improves survival in an experimental model of acute pancreatitis

The development of systemic complications in acute pancreatitis is largely responsible for the mortality associated with this disease. The systemic sequelae encountered in acute pancreatitis are similar to those occurring in patients with septic shock, a syndrome of multiple organ failure thought to be related to overproduction of inflammatory cytokines. As with sepsis, data is mounting that cytokines, particularly TNF alpha, may play a central role in acute pancreatitis and mediate the systemic sequelae of the disease. We have previously shown elevated levels of TNF alpha in the serum of animals with experimental acute pancreatitis. In this study, we use a bile-infusion model of pancreatitis in the rat to show amelioration of disease severity as well as a distinct survival advantage by TNF alpha blockade using anti-TNF alpha polyclonal antibody. These data provide strong evidence that TNF alpha is a major contributor to the morbidity and mortality from acute pancreatitis.

Glomerulosclerosis as a determinant of posttransplant function of older donor renal allografts

Transplantation of kidneys from older donors is being advocated to expand the organ donor pool. However, the prevalence of atherosclerosis and age-induced renal structural alterations account for the variable function of allografts procured from these older donors. Pretransplant biopsies are sometimes used to evaluate kidneys from older donors, but to date there are no defined criteria correlating the extent of structural alterations in these kidneys to subsequent function. We investigated the effect of glomerulosclerosis, a marker for nephrosclerosis, on graft outcome. Sixty-five baseline biopsies of kidney allografts were retrospectively analyzed to identify a referent point of glomerulosclerosis that correlated with inferior graft outcome. Age and death from nontraumatic cerebrovascular injuries were the main correlates for donor glomerulosclerosis (P < 0.001). Allografts with poor function at 6 months defined as serum creatinine > 2.5 mg/dl (n = 13) or nephrectomy (n = 4) had a mean of 20% glomerulosclerosis at the time of implantation compared with only 2% sclerosis in allografts with good function (P < 0.05). Delayed graft function occurred in 22% and 33% of recipients with no glomerulosclerosis and those with less than 20% glomerulosclerosis, respectively. In contrast, patients receiving kidneys with > 20% sclerosis had an 87% incidence of delayed function (P < 0.05). Moreover, graft loss occurred in 7% of recipients of kidneys with less than 20% sclerosis and in 38% of recipients with > 20% sclerosis (P < 0.04). Measurements of serum creatinine in the donors did not distinguish the different degrees of glomerulosclerosis found on biopsy. Our data indicate that donor glomerulosclerosis greater than 20% increases the risk of delayed graft function and poor outcome of transplanted kidneys. Therefore, we advocate the use of routine biopsies of kidneys from older (> 50 yrs) donors and those donors with nontraumatic cerebrovascular accidents, despite seemingly normal preprocurement serum creatinine.

Results of pancreas transplantation with portal venous and enteric drainage

PURPOSE

The standard method for pancreatic transplantation involves drainage of exocrine secretions into the urinary bladder with venous outflow into the systemic circulation. Despite the high success rate associated with this approach, it often leads to complications, including chemical cystitis, reflux pancreatitis, metabolic acidosis, and hyperinsulinemia. The authors developed a new technique of pancreatic transplantation with portal drainage of endocrine secretions and enteric drainage of exocrine secretions (PE), which theoretically should be more physiologic.

PROCEDURES

All patients were insulin-dependent diabetics with end-stage renal disease who underwent combined kidney-pancreas transplantation. Between 1990 and 1994, 19 patients have been transplanted using intraperitoneal placement of the pancreas allograft with exocrine drainage into a Roux-en Y loop and venous drainage into the portal circulations (PE). A comparison group of all patients undergoing standard systemic-bladder (SB) transplantation between April 1989 and March 1993 (n = 28) also was studied. Patient follow-up ranges from 6 months to 5 years for the SB patients (mean = 2.5 years) and 6 months to 4 years for the PE patients (mean = 1.6 years). Routine follow-up includes documentation of the clinical course and detailed endocrine studies.

FINDINGS

Patient and graft actuarial survival at 1 and 3 years is no different for SB and PE patients. Urinary tract infections occurred in 89.3% of the SB patients (2.8/patient) versus 26.3% of the PE patients (0.25/patient, p < or = 0.0001). None of the PE patients experienced hematuria compared with 53.6% of the SB patients (p < or = 0.0001); however, two PE patients had melanotic episodes. The incidence of urinary retention and reflux pancreatitis was 32.1% versus 5.3% (p < or = 0.028) for SB and PE groups, respectively. Patients in the SB group required sodium bicarbonate therapy (mean = 55 mEq/day) although no PE patient required routine therapy; despite this, SB patients experienced more episodes of acidosis (44 vs. 5). Endocrine studies indicate no difference in glycosylated hemoglobin or fasting and stimulated glucose values throughout the follow-up period. In contrast, hyperinsulinemia was evident in both fasting and stimulated tests for the SB patients, with values consistently two- to fivefold higher than those of the PE group.

CONCLUSIONS

These results indicate that PE and SB pancreas transplantation are equivalent in terms of patient and graft survival and suggest that the PE approach is associated with a decreased incidence of metabolic and bladder-related complications. In addition, the PE approach eliminates the state of peripheral hyperinsulinemia that characterizes the SB procedure. Continued follow-up will be necessary to determine if long-term outcomes will differ for patients with PE and SB grafts.

An analysis of renal function in pancreas-kidney and diabetic kidney-alone recipients at two years following transplantation

Pancreas-kidney recipients (SPK) are at higher risk for rejection than diabetic kidney-alone recipients (KA), and thus generally receive higher doses of maintenance immunosuppression. This has lead to concern that the potential benefits to renal function, brought about by posttransplant euglycemia, may be negated by the nephrotoxicity of immunosuppression. We therefore sought to compare patterns of renal function in diabetic patients following SPK and KA transplantation. Serum creatinine levels, corrected glomerular filtration rates (cGFR), and whole blood TDX cyclosporine levels were recorded on 25 SPK and 17 KA at 3, 6, 12, and 24 months posttransplant when patients were free of acute renal dysfunction. The SPK recipients had significantly higher cyclosporine levels at each of the measurement points as compared with the KA recipients (P < or = .01). In spite of these higher cyclosporine levels, the SPK recipients showed stable creatinine and cGFR levels throughout the study, as did the KA group until 24 months. At 24 months, the KA group experienced a rise in creatinine from 1.3 +/- .09 ng/dl at 3 months to 1.6 +/- .07 ng/dl at 24 months (P < or = 0.006). Urine albumin excretion was examined at 24 months, and 6 of 8 KA patients found to have abnormally elevated levels compared with only 3 of 9 SPK patients. These findings indicate that SPK recipients experience stable renal function despite significantly higher cyclosporine levels, while KA recipients demonstrate early signs of deteriorating function at the 2-year follow-up.

Induction of acute pancreatitis in germ-free rats: evidence of a primary role for tumor necrosis factor-alpha

BACKGROUND

Tumor necrosis factor-alpha (TNF-alpha) has been implicated as a mediator of the systemic manifestations associated with acute pancreatitis. The purpose of this study was to show that TNF-alpha expression in pancreatitis is a primary response and is not the result of endotoxemia.

METHODS

Severe acute pancreatitis was induced in germ-free rats, which have no source of endogenous endotoxin, by ductal infusion of artificial bile. Control animals underwent sham operation and ductal infusion of saline solution. TNF-alpha levels were measured by the WEHI bioassay. Endotoxin was measured by the Limulus assay.

RESULTS

TNF-alpha levels remained low in the sham group (mean, 24.6 +/- 8.0 pg/ml) but were significantly elevated in normal rats with pancreatitis (181 +/- 26.8 pg/ml; p < 0.001 versus sham group) and in germ-free rats with pancreatitis (213 +/- 90 pg/ml; p < 0.002 versus sham group). No endotoxin was detected in any of the experimental rats.

CONCLUSIONS

Our results indicate that TNF-alpha levels are elevated in acute pancreatitis despite the absence of endotoxin, indicating a primary role of TNF-alpha in this disease.

Terminal complement complexes in acute poststreptococcal glomerulonephritis

Activation of the complement cascade occurs in most cases of acute poststreptococcal glomerulonephritis (APSGN) and results in the formation of the terminal complement complexes (TCC). To examine the possible role of TCC in the pathogenesis of glomerular injury in APSGN, we studied 30 patients with the clinical diagnosis of APSGN. All patients had an elevated plasma SC5b-9 concentration at the onset of clinical nephritis. Serial plasma concentrations showed an inverse linear relationship with time after onset of clinical disease (r = -0.59, P = 0.0008), while plasma C3 concentrations showed a positive linear relationship (r = 0.78, P = 0.0001). Renal biopsies of 5 patients demonstrated co-localization of C5b-9, S-protein, and C3 deposition in a glomerular capillary loop and mesangial distribution. Urinary excretion of TCC in the acute phase of APSGN was not elevated and was not a useful marker of disease activity. These data suggest that in APSGN with terminal complement pathway activation the local generation of TCC may contribute to the pathogenesis of the disease.

Renal pathology in pre-eclampsia

Pre-eclampsia affects the kidney both functionally and morphologically. Renal haemodynamics decrease and urinary protein excretion increases, in part due to lesions affecting the glomerulus, where a combination of changes produces a characteristic appearance and permits differentiation of pre-eclamptic nephropathy from other glomerular alterations associated with hypertension in pregnancy. In pre-eclampsia the glomerulus is diffusely enlarged and bloodless, due not to proliferation, but to hypertrophy of the intracapillary cells. These alterations, best described ultrastructurally, include hypertrophy of the cytoplasmic organelles in endothelial and occasionally mesangial cells, particularly the lysosomes, which undergo marked enlargement and vacuolization (due to accumulation of free neutral lipids). These reactive changes have been termed 'glomerular capillary endotheliosis'. Other lesions, observed occasionally, include subendothelial and mesangial electron-dense deposits, as well as interposition of mesangial cell cytoplasm or mesangial matrix along an otherwise normal basement membrane. Some investigators have described immunohistological findings (presence of IgM, IgG and fibrin) which they believe specific for pre-eclampsia, and others have claimed the disease may cause focal segmental glomerulosclerosis (FSGS). We believe the immunohistological findings are non-specific and insudative, and that FSGS when present predates the pre-eclamptic complication. Finally, the renal lesions appear fully reversible and the disease has no remote cardiorenal effects on its patients.

Cytokine stimulation of prostaglandin production inhibits the proliferation of serum-stimulated mesangial cells

Mesangial cell proliferation contributes to glomerulosclerosis and is associated with the development of end-stage renal disease. We examined the effects of the cytokines interleukin 1 (IL-1 beta) and interleukin 6 (IL-6) on the mitogenesis and proliferation of rat glomerular mesangial cells. Exposure of serum-stimulated cells to IL-1 beta and IL-6 for 48 hours resulted in a dose-dependent inhibition of both mitogenesis, determined by 3H-thymidine incorporation, and proliferation, determined by absolute cell counts. Both IL-1 beta and IL-6 stimulated endogenous PGE2 production in this cell system. Cyclooxygenase inhibition by indomethacin and meclofenamate abrogated the inhibitory effects of both IL-1 beta and IL-6. Furthermore, addition of exogenous PGE2 to cytokine-stimulated cells in which cyclooxygenase activity was blocked resulted in inhibition of mitogenesis, while addition of exogenous aracidonic acid to the cytokine-stimulated cells enhanced the induced inhibition of mitogenesis. These results demonstrate that in serum-stimulated mesangial cells, both IL-1 beta and IL-6 inhibit mitogenesis and proliferation, and that these effects are mediated, in part, by stimulated endogenous prostaglandin production.

Randomized double-blind study of standard versus low-dose OKT3 induction therapy in renal allograft recipients

A double-blind, randomized, prospective study was undertaken to determine if the dose of OKT3 used for induction immunosuppression following kidney and kidney-pancreas transplantation affected clinical outcomes. Twenty-five patients were randomized in each group. Five patients in each group received a combined kidney/pancreas transplant. All patients received sequential quadruple immune suppression (azathioprine and methylprednisolone, followed by oral prednisone and cyclosporine A), regardless of randomization to the standard (5 mg) or low-dose (2 mg) OKT3 group. OKT3 was administered for 7 to 14 days. The dose of OKT3 was adjusted to ascertain the clearance of peripheral positive CD3 lymphocytes. The mean cumulative OKT3 dose for the standard dose group was 52.0 mg versus 23.4 mg for the low-dose group (P < 0.00001). Dosage increases were necessary for 29% of the standard dose and 32% of the low-dose patients. The side effect score for the standard versus low-dose group was not statistically different (0.79 +/- 0.58 v 0.84 +/- 0.68), except for chills, which occurred more frequently in the low-dose-treated patients (P = 0.003). Anti-OKT3 antibodies developed with similar frequency in both dosage groups, with 8% exhibiting titers of 1:500 or greater at the end of treatment. Kidney graft survival was 96% for the standard dose and 92% for the low-dose group. The overall incidence of rejection was similar in both groups; however the low-dose group did experience an increase in early rejection episodes. The incidence of major and minor viral and bacterial infections was also similar for both dosage groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Coexistence of anti-neutrophil cytoplasmic antibody-associated glomerulonephritis and membranous glomerulopathy

The association of renal Wegener's granulomatosis with other glomerular diseases is very rare. A case of anti-neutrophil cytoplasmic antibody-associated necrotizing glomerulonephritis superimposed on a membranous glomerulopathy in a patient with systemic Wegener's granulomatosis is reported. Renal failure was corrected by immunosuppressive therapy treatment, but a non-nephrotic-range proteinuria persisted for several months. The association of membranous glomerulopathy with anti-glomerular basement membrane disease and other autoimmune diseases is well described; however, anti-neutrophil cytoplasmic antibody-associated vasculitis superimposed on membranous glomerulopathy has not been reported previously.