Renal transplantation in the inbred rat. 3. A study of heterologous anti-thymocyte sera.

Heterologous rabbit anti-rat thymocyte sera, its immunoglobulin G fraction, and the bivalent and univalent antibody fragments obtained by pepsin digestion are potent immunosuppressive reagents when tested in a system of renal allotransplantation between the LBN F(1) hybrid and Lewis rat strains. The AT F(ab')(2) is not lymphocytotoxic in vitro but has agglutinating ability, while the AT Fab' neither agglutinates nor is cytotoxic to rat lymphocytes, but will inhibit the in vitro reaction. The AT IgG and the F(ab')(2) are more immunogenic in their host than normal rabbit IgG and F(ab')(2), probably due to increased delivery of the antibody to the immune system. Donor pretreatment studies demonstrate that a cross-reacting, highly immunogenic antibody with anti-lymphocyte specificity may bind to renal sites and be transferred to the new host after transplantation. In addition, the crude unabsorbed anti-thymocyte antisera may induce a nephritis characteristic of immune complex disease which can be eliminated by complete absorption with serum proteins. Further in vivo and in vitro evidence is presented that the AT IgG contains small amounts of antibody to glomerular basement membrane antigens and may induce an autologous phase-nephrotoxic nephritis. The amount of in vivo binding by AT IgG to GBM was reduced by subcutaneous rather than intravenous administration. Most of the rabbit antisera tested contain antibody in low titer to sheep erythrocytes and in vivo experiments indicate that the nature of the immunodepressive effect of AT globulin to sheep erythrocytes is due in part to the passive transfer of antibody and is not necessarily due to a specific anti-lymphocyte effect.

The modulating influence of cyclic nucleotides upon lymphocyte-mediated cytotoxicity.

The capacity of allosensitized thymus-derived lymphocytes to destroy target cells bearing donor alloantigens is modulated by the cellular levels of cyclic AMP and cyclic GMP. Increases in the cyclic AMP levels of attacking lymphocytes by stimulation with prostaglandin E(1), isoproterenol, and cholera toxin inhibit lymphocyte-mediated cytotoxicity; whereas, depletion of cyclic AMP with imidazole enhances cytotoxicity. The augmentation of cytotoxicity produced by cholinergic stimulation with carbamylcholine is not associated with alterations in cyclic AMP levels and is duplicated by 8-bromo-cyclic GMP. The effects of activators of adenylate cyclase, cholinomimetic agents, and 8-bromocyclic GMP are upon the attacking and not the target cells and occur at the time of initial interaction of attacking and target cells. Indeed, the level of cyclic nucleotide (cyclic AMP and cyclic GMP) at the time of initial cell-to-cell interaction determines the extent of cytotoxicity.

Microtubule function in immune and nonimmune lymphocyte-mediated cytotoxicity.

Disaggregation of microtubular subunits in effector lymphocytes inhibits their ability to injure target cells. The inhibition is not reversed by denterium oxide, an agent known to stablize microtubular subunits.

Complement metabolism in man: hypercatabolism of the fourth (C4) and third (C3) components in patients with renal allograft rejection and hereditary, angioedema (HAE).

Highly purified and radioiodinated human C4 and (or) C3 were administered to patients with renal allografts in rejection, with hereditary angioedema (HAE), with chronic glomerulonephritis, and to control subjects. The latter group included normal individuals, anephric patients before transplantation, and stable renal allograft recipients. The catabolic rates of these complement proteins were determined by analysis of the disappearance of plasma protein-bound radioactivity (k(m)), and by direct measurement of urinary excretion of radioactivity (k(u)). The correlation coefficient between these two methods was 0.96. The mean +/-2 SD for catabolic rates in the control subjects was 0.9-2.7% plasma pool/hr for C4 and 0.9-2.0% plasma pool/hr for C3. Patients experiencing renal allograft rejection had unstable levels of C4 and C3, and exhibited moderate hypercatabolism of both proteins. One patient with chronic glomerulonephritis had hypercatabolism of C4 and C3 in the presence of stable normal serum levels. In patients with HAE who had extremely low levels of C4, catabolic rates for C4 were markedly elevated (3.7, 5.8, 7.0 and 8.8%/hr). Analysis of plasma curves in HAE revealed a three component disappearance curve instead of the two component curve in control subjects receiving the same preparation. Even though C3 levels were normal, moderate hypercatabolism of C3 was also present in HAE (2.6, 2.8, 2.8, and 3.2% of pool/hr). The marked hypercatabolism of C4 in HAE constitutes the first direct evidence for the in vivo destruction by uninhibited C1 esterase of its natural substrate C4. The moderate hypercatabolism of C3 is consistent with the in vivo formation of C3-convertase.

Intrarenal distribution of blood flow in the transplanted dog kidney: effect of denervation and rejection.

Serial measurements of intrarenal distribution of blood flow have been recorded in anesthetized dogs with the (133)xenon "washout" technique. The results showed that normal kidneys redistributed their blood flow after laparotomy and mobilization of the kidney. This alteration consisted of a diminution in percentage of total renal blood flow supplied to the fastest flowing component, and a diminution of renal mass supplied by that component. This effect lasted for as long as 7 days. Thereafter, the blood flow distribution remained stable. Autotransplanted kidneys had a stable distribution of blood flow between 0 and 77 days after operation, the values being identical with the stable normal kidney. Homotransplanted kidneys had the same intrarenal distribution of blood flow after operation as the autotransplanted kidneys. Whereas the intrarenal distribution of blood flow of the autotransplanted kidneys remained stable, a redistribution occurred in the homotransplanted kidneys as rejection progressed. This phenomenon occurred before marked elevation of blood urea nitrogen. The redistribution was due to a decrease in percentage of blood flow supplied to the fastest flowing component, and a relative reduction of tissue mass perfused by this component. Radioautography of the kidneys before rejection demonstrated that the cortex was homogeneously perfused by the fastest flowing component of blood flow. As rejection progressed, a reduced area of cortex was perfused by this component. Terminally, the fastest flowing component was located in the outer medulla. It is suggested that the reduction in cortical blood flow produced by immunological mechanisms may play a prominent role in the ensuing renal failure.

Vestibular toxicity of gentamicin. Incidence in patients receiving long-term hemodialysis therapy.

Twenty-three patients on long-term hemodialysis regimens who received gentamicin sulfate were reviewed retrospectively to assess the incidence of ototoxicity and to identify potential risk factors. Dosage of gentamicin sulfate was 1.0 to 1.5 mg/kg intravenously three times weekly. Serum gentamicin levels were monitored in 21 cases. Seven patients developed signs and symptoms of vestibular dysfunction. Statistically significant differences were found between the ototoxic and nonototoxic groups with respect to age (P less than .001), total dose (milligrams per kilogram) (P less than .001), and duration of therapy (P less than .001). The total dose per kilogram of body weight contributed most heavily to ototoxicity, and regression analysis suggests that the critical cumulative dose is about 17.5 mg/kg. The two groups did not differ with respect to mean peak and valley serum levels. We conclude that this population is at high risk of developing gentamicin-related vestibular dysfunction specifically when the cumulative dose exceeds 17.5 mg/kg.

Renal vascular tone in essential and secondary hypertension: hemodynamic and angiographic responses to vasodilators.

The renal vascular response to graded doses of acetylcholine, dopamine and phentolamine, assessed by xenon washout and selective arteriography was used to define the relative contribution of fixed and reversible vascular abnormalities to increased renal vascular resistance in patients with essential or secondary hypertension. The increase in blood flow induced by acetylcholine and dopamine was blunted strikingly in patients with advanced nephrosclerosis, chronic pyelonephritis and polycystic kidney disease and was normal in the kidney contralateral to a significant renal artery stenosis. Conversely, the response to both was potentiated in 9 of 13 (69%) patients with mild essential hypertension. Equivalent potentiation of the response to acetylcholine was induced in normal subjects by increasing renal vascular tone pharmacologically with angiotensin. Phentolamine infused into the renal artery also increased renal blood flow significantly in 6 of 9 (67%) patients with mild essential hypertension, but in none of 15 normal subjects, over a dose reange that paralleled that for alpha-adrenergic blockade. Changes in the selective renal arteriogram were in excellent accord: potentiated response to acetylcholine, phentolamine or dopamine was associated with reversal of the small vessel abnormalities visualized in the arteriogram. The reduced blood flow response in advanced nephrosclerosis or parenchymal disease was associated with a reduced angiographic change during dilator infusion. The results suggest a quantitatively important, functional renal vascular abnormality--perhaps mediated by the sympathetic nervous system--in many patients with mild essential hypertension. Conversely the renal vascular abnormality associated with advanced nephrosclerosis or renal parenchymal disease is largely fixed and is probably due to organic changes.

Bone marrow transplantation following total lymphoid irradiation. I. Correlation with field size and suppressor cell induction.

Total lymphoid irradiation (TLI) induces a unique state of immunosuppression. Although permanent bone marrow chimerism has been obtained in rodents prepared by TLI, uniform marrow engraftment has been more difficult to obtain in larger mammals. Accordingly, studies were performed to assess the immunologic perturbations induced by TLI in inbred LEW rats, and to explore the effect of altering field size of irradiation on the induction of suppressor cells and the success of allogeneic bone marrow transplantation. Additional abdominal shielding to protect a single kidney (right) from irradiation during TLI presented successful of bone marrow engraftment (WF leads to LEW, N = 5) but chimerism was uniformly obtained (N = 3) using the full irradiation field (P less than .05) Lymphopenia and a relative monocytosis were noted in all rats subjected to TLI. Although TLI using the full irradiation field eliminated alloreactivity of nylon-wool-purified spleen cells, significant, if reduced, alloreactivity was noted in rats subjected to TLI using smaller irradiation fields. Irradiated (1500 rads) nylon-wool-purified splenic T cells of rats subjected to TLI using the full field effected significantly greater suppression (P less than .001) of a normal mixed lymphocyte culture than did cells from rats subjected to TLI with right kidney shields in place (relative response reduced to 15.2 +/- 5.7% versus 64.3 +/- 11.7%). Success of bone marrow engraftment in rats prepared by TLI was correlated, therefore, with the induction of a profound lymphopenia, elimination of alloreactivity, and the development of a potent splenic suppressor system.

Acute renal failure following cardiac operations.

The incidence and course of acute renal failure following cardiopulmonary bypass (CPB) was retrospectively analyzed. The incidence of oliguric acute renal failure was 1.5% and the mortality rate was 27%, a figure substantially lower than previously reported. Both peritoneal dialysis and hemodialysis were initiated early, with a mean of 3.6 days between the onset of acute renal failure and initiation of dialysis. Survivors had a mean duration of acute renal failure of 24 days. Deaths were caused by cardiac failure (one) and sepsis (two). Mortality rate from acute renal failure complicating CPB resembles that from acute renal failure related to other causes and may be lowered by early aggressive dialysis.

Recommendations for evaluation of the cardiovascular response of dialysis patients.

The minimum parameters, which I have stressed in the first section, should be measured at least once a week, as should the chest films, the films of the vessels and so on, plus the chemistries, probably when determined by the investigator. If we are going to compare program to program, these intervals should, of course, be synchronized. The more sophisticated parameters, which I have mentioned, should be measured perhaps only when specific areas are to be investigated because the number of things which we think need to be measured is, indeed, enormous for any one laboratory. Now, if such studies are to be carried out by a number of investigators, the standard form mentioned should be instituted and yearly meetings of such groups should be held to compare notes, and particularly the adequacy of the data obtained and the method of obtaining it. Initially perhaps, after the program is underway, if enough groups are actively involved, the first meeting probably should be held six months after the beginning of the evaluation. I realize what we have put forth here is ambitious. I think it is probably wise to put in as many things as possible which might be important, and then with a little rethinking time, obviously some of these things can be eliminated. To my knowledge, we have covered almost everything that needs to be covered, and what we need to do now, perhaps, is to thin this out a little bit with discussion and consultation.

Cardiovascular disease in uremic patients on hemodialysis.

In conclusion, patients on chronic maintenance dialysis have an increased incidence of death from cardiovascular disease. Hypertension plays a major role, and these patients must be carefully monitored for complete control of blood pressure. Adequacy of ultrafiltration to maintain normal extracellular volume is an essential part of the dialytic treatment. Hypertensive patients should be screened for excessive renin secretion because of its possible role in unresponsive hypertension in patients on dialysis. Nephrectomy should be used when necessary, where dialysis and antihypertensive medication have not adequately controlled blood pressure. Patients must be monitored for the presence of pericardial disease to avoid subsequent pericardial effusion and the development of constrictive pericarditis with its adverse effect on myocardial function. When constrictive pericarditis is present, it obviously should be relieved by appropriate surgery. Efforts should be made to minimize cardiac output in hemodialysis patients. Whether or not routine transfusions to maintain a higher hematocrit are indicated is a question that cannot yet be answered. However, patients with marginal cardiovascular function who are accepted on hemodialysis and must have an arteriovenous shunt should be supported in any manner to minimize an increase in cardiac output. Early and aggressive treatment of known episodes of sepsis is important in the elimination of valvular endocarditis in this patient population. Perhaps one of the finer indicators of adequacy of hemodialysis will be K rate and peak immunoreactive insulin levels. Continued abnormality of these parameters may contribute to cardiovascular disease. Clearly, further study of the effect of abnormal carbohydrate metabolism on lipid metabolism is in order. Serum triglyceride, serum cholesterol and lipid electrophoretic pattern should be followed to evaluate the beneficial effects of drug therapy and changes in dialytic technique on the development of cardiovascular disease. Careful monitoring of calcium, phosphorus, bone films and parathyroid hormone levels is indicated to assess parathyroid status. The use of aluminum binders and parathyroidectomy to prevent vascular and myocardial calcification is important in the therapy of these patients. The use of cardiac catheterization, coronary artery arteriography, and possibly cardiac vascular repair, should be considered in the chronic hemodialysis patient with coronary artery disease if he is otherwise well. Adequacy of hemodialysis perhaps can be evaluated through its effect on all of the above parameters. Whether or not changes in artificial kidney treatments can correct the final vascular disease remains to be seen.

Testosterone therapy in hemodialysis patients.

30 patients undergoing regular, three times weekly hemodialysis were treated with large doses of intramuscular testosterone with evaluation of hematopoiesis before and after treatment. A control group of 30 patients not using the drug was evaluated in similar fashion. The presence or absence of native kidneys was the most important factor determining hematocrit level and transfusion requirements in these patients, whether treated with testosterone or not. The mean hematocrit was lower and the transfusion requirements were higher in bilaterally nephrectomized patients. A significant increase in hematocrit occurred in testosterone treated nephric patients, but untreated nephric patients also had a significant rise. Important adverse side effects occurred with testosterone. Anephric patients did not increase hematocrit levels with or without testosterone.