Immunosuppressive drug-free operational immune tolerance in human kidney transplants recipients. Part II. Non-statistical gene microarray analysis

Kidney transplant is the reference treatment for patients with end-stage renal disease, but patients may develop long-term rejection of the graft. However, some patients do not reject the transplant, but instead are operationally tolerant state despite withdrawal of immunosuppressive treatment. In this second article we outline a microarray-based identification of key leader genes associated respectively to rejection and to operational tolerance of the kidney transplant in humans by utilizing a non/statistical bioinformatic approach based on the identification of "key genes," either as those mostly changing their expression, or having the strongest interconnections. A uniquely informative picture emerges on the genes controlling the human transplant from the detailed comparison of these findings with the traditional statistical SAM (Tusher et al. 2001 Proc Natl Acad Sci USA 98:5116-5121) analysis of the microarrays and with the clinical study carried out in the accompanying part I article.     

Results of 250 consecutive cadaver kidney transplants.

The results of 250 cadaver kidney transplants performed at this hospital between May 1968 and December 1974 were analysed. A functioning transplant was defined strictly as one that maintained the recipient in good health with a serum creatinine below 442 mumol/1 (5 mg/100 ml) without any need for dialysis. The proportions of kidneys functioning after one, two, and three years were 40-4%, 33-9%, and 31-1% respectively, the corresponding survival rates of patients being 62-6%, 57-4%, and 43-8%. The primary failure rate overall was 21-6%, while the failure rates for first, second, and third transplants were 18-1%, 39-9%, and 66-7% respectively. Half of the primary failures were attributed to the use of cadaver kidneys with abnormal vasculature or long ischaemic times or originating from non-ventilated donors. Of the initially successful transplants 49% were subsequently lost due to rejection (53%) or death of the patient with a functioning transplant (46%), and of the secondary losses 58% occurred within three months of transplantation. HLA matching of donor and recipient for two or more antigens was associated with a significant increase in transplant survival--46% at three years as opposed to 9-5% at three years for kidneys with poorer matches.     

Composite tissue allografts in rats: IV. Graft-versus-host disease in recipients of vascularized bone marrow transplants.

This laboratory has used a composite tissue allograft model as a vehicle for studies on a new type of bone marrow transplant, the vascularized bone marrow transplant. The model consists of a rat hind limb transplant that incorporates integumentary musculoskeletal, and lymphopoietic tissues. These transplants, in comparison with conventional marrow transplants, have the advantage of providing a syngeneic microenvironment and immediate engraftment of both mature and progenitor hemopoietic cells at the time of transplantation. The characteristics of graft-versus-host disease were studied in this model. Lewis X Brown Norway F1 (LBN RT-1(1+n)) rats received hind limbs from Lewis (LEW RT-1(1)) donors (n = 19). Animals were observed daily for signs of graft-versus-host disease. Necropsies were performed. A minority of animals developed lethal disease (7 of 19 recipients) and demonstrated cachexia with concomitant histopathologic changes of the disease. Acute and chronic groups emerged with distinct clinical courses, which are similar to other models of this disease. Recipients of vascularized bone marrow transplants (limb transplants) showed clinical and histopathologic changes of the disease. The transplants may be used as a model of graft-versus-host disease in humans. Most interestingly, the transplant has a lower incidence of disease compared with other methods of bone marrow transplantation and represents an alternative to conventional bone marrow transplantation, which deserves further exploration. It may be possible to develop a new technique for bone marrow transplantation based on this surgical approach. It is proposed that the transfer of vascularized blocks of bone/marrow into prospective recipients as opposed to cellular bone marrow transplants may be preferable.     

Candidiasis, aspergillosis and other invasive mycoses in recipients of solid organ transplants

Invasive fungal diseases (IFD) are important causes of solid organ transplant-related morbidity and mortality. Modifications and improvements in the transplant surgical procedures, supportive care, and advances in the diagnosis and treatment of these IFD have produced notable changes in their epidemiology and outcome. Candida and other yeast genera continue to play an important etiological role, but Aspergillus and other filamentous fungi are the cause of most IFD in lung transplant recipients. This review is an update of the relevant findings in the literature related to the epidemiology, diagnosis and treatment of IFD in solid organ transplant recipients, with a main focus on invasive aspergillosis and candidiasis.     

Surveillance of Toxoplasma gondii infection in recipients of thoracic solid organ transplants

We evaluated the frequency of seroconversion for toxoplasmosis in seronegative recipients of thoracic solid organ transplants with seronegative or seropositive donors and the efficacy of chemoprophylaxis with pyrimethamine+sulfametopirazine. One hundred and sixty one patients seronegative for toxoplasmosis were followed-up at different intervals. Six patients out of 79 R-/D- and twelve out of 82 R-/D+ seroconverted after chemoprophylaxis interruption. There was no difference between matched and mismatched recipients as to the frequency of seroconversion which therefore could not be related to donor seropositivity. Seroconversions were almost asymptomatic. All positive recipients should be tested if symptoms of infection are present.     

Anemia induces accumulation of erythropoietin mRNA in the kidney and liver.

Regulation of the production of erythropoietin occurs in the kidney and liver largely through control of accumulation of erythropoietin mRNA. Erythropoietin mRNA was first detected in kidneys at 1.5 h postanemia and reached a plateau value at least 200-fold above the control value by 4 to 8 h. A 20-base sequence immediately upstream from the reported erythropoietin mRNA initiation site is complementary to a hypervariable sequence in 18S rRNA.     

Voriconazole for the therapy of mycoses in recipients of solid organ transplants

Invasive fungal infections (IFI) are the third cause of infectious complications in recipients of solid organ transplants (SOT), showing an incidence of 5-42% depending of the trasplanted organ. Moreover, IFI account for significant morbility and mortality in SOT, ranging between 25-95% depending on the type of fungus and its organ localization. Different strategies (prophylaxis, preemptive treatment, treatment, antifungal combinations, routes of administration) have been tested to improve the prognosis of IFI in SOT. To reach this objective, it was essential to have access to new antifungals showing a higher spectrum of activity on the fungal pathogens, both classical and emerging, and showing improvements in pharmacokinetic and pharmacodynamic characteristics, ease of administration and acceptability and lower rates of adverse effects. Introduction of voriconazole in the therapeutic arsenal has facilitated to reach these goals due to its special pharmacological characteristics, its in vitro antifungal activity and the in vivo clinical efficacy demonstrated in different studies.     

Effect of immunosuppressive and other drugs on the cortisol-cortisone shuttle in human kidney and liver.

BACKGROUND: Impaired 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2) has been suggested in patients with hypertension or renal disease, where it may contribute to sodium retention and hypertension. 11beta-HSD1, which is expressed predominantly in liver and adipose tissue, influences glucose homeostasis and fat distribution by altering intracellular cortisol (F) concentrations. We tested immunosuppressive drugs that cause hypertension, and substances that interfere with steroidogenesis or influence glucose homeostasis for their ability to influence the inhibition of 11beta-HSD isozymes. METHODS: For inhibition experiments, we used microsomes prepared from unaffected parts of human liver segments and resected human kidney cortex because of hepatocarcinoma or renal cell cancer. The inhibitory potency of several compounds was evaluated in concentrations from 10(-9)-10(-5) mol/l. RESULTS: Only sirolimus, but not cyclosporine A, tacrolimus, mycophenolate mofetil, or azathioprine showed a slight inhibition of 11beta-HSD2 activity. None of the drugs that inhibit steroidogenesis (suramine, mitotane, etomidate, and aminogluthethimide) or steroid metabolism (rifampicine) influenced 11beta-HSDs, nor did ginsenoides Re, Rc, and Rb1. Among sulfonylureas, only gliclazide decreased significantly 11beta-HSD1 activity. CONCLUSIONS: Increased blood pressure due to immunosuppressive drugs is probably not caused by direct inhibition of 11beta-HSD2. An additional glucose lowering effect of sulfonylurea gliclazide may be due to its ability to inhibit 11beta-HSD1.     

Differentiation of hematopoietic and stromal elements of extramedullary bone marrow transplants in irradiated recipients

The growth of bone marrow transplants under the renal capsule is stimulated in the mice irradiated at a dose of 700 r. The size of transplants increases, primarily, at the expense of hemopoietic tissue. The osteogenic potencies of stromal elements remain at a high enough level as well. Some features which characterize the decrease of viability of hemopoietic cells may be due to incomplete restoration of the system of sinusoidal capillaries.     

Aluminium accumulation and distribution in the freshwater clams (unionidae)

1. Freshwater unionids (Anodonta anatina L. and Unio pictorum L.) were exposed to aluminium (300 and 900 μg/l, nominal) in continuous (3 weeks) and fluctuating (24 days) acid exposures.2. In addition, accumulation was monitored for 2 weeks under semi-static acid (pH4-5) and circumneutral (pH 6.6-8.3) conditions in hard (35 mg Ca/l) and soft water (3.5 mg Ca/l).3. In addition, a fluctuating exposure of 24 days, consisting of three intermittent pulses which combined low pH (4–5) and high Al (900 μg/l) concentration, was performed.4. The various organs of A. cygnea, collected from a watershed with relatively high heavy metal concentrations, were analyzed for their Al and Cd concentrations.5. The ultimate order of the Al and Cd concentration in these clams was identical: kidney ≥ midgut gland ≥ rest ≥ gill ≥ mantle.6. During the 3 weeks of exposure, the Al concentration in the gills and kidney increased linearly, and saturation level was not reached.7. The Al concentration in the calcium concretion material isolated from the gills was lower than that of the whole organ.8. An elimination period of 12 weeks was needed to reach the background level of Al in the gills, whereas in the kidney the initial Al concentration was reached after 4 weeks of elimination.9. In both species, the ambient pH had a significant effect on the Al accumulation in the gills, whereas the effect of the water hardness was only of minor importance.10. Rapid elimination of the Al accumulated in the gills of U. pictorum during the episodic 3-day exposure was recorded.     

Role of serum and urinary Tamm-Horsfall protein in the surveillance of kidney transplants

The study of 24-h urinary excretion proves to be quite interesting from a theoretical point of view on account of its topographic origin in the nephron and from a practical point of view to control renal transplant patients with favourable or unfavourable course. In both cases, the results we obtain are in accordance with that of blood creatinine assay and ratio N-acetyl-beta-D-glucosaminidase (NAG)/creatinine in urine. The prolonged study of serum THG concentration confirms the previous data regarding the outcome of renal grafts. Moreover, particularly low concentration rates probably imply the interference of factors such as: renal toxins or anti-THG autoantibodies.     

Studies on the immunosuppressive effect of organochlorine and organophosphoric pesticides in subacute experiments.

Subacute experiments were carried out on rabbits by daily oral administration of Lindane, Malathion and Dichlorophos. A dose-dependent significant decrease in Salmonella typhi induced immune response was found in sera of animals treated with these pesticides compared to untreated controls. Inihbition of cholinesterase activity confirmed the immunological findings.