1. Pathology of Kidney and the Urinary tract Dr. Amar C. Al-Rikabi Dr. Hala Kasouf Kfouri

2. Pathology of Renal Transplantation Lecture -6

3. Renal Transplantation is increasingly being performed as a treatment for end-stage renal failure.

5. Vascular access for long-term hemodialysis is usually provided through a surgically created arteriovenous fistula. Blood leaves the patient through the distal needle to pass through the distal needle to pass through the dialyser before returning to the patient through the proximal needle. Patients usually become adept to inserting their own needles.

9. Renal transplantation Note the two end-stage native kidneys in normal position, the atrophic first donor kidney (lower left), and the larger second donor kidney (lower right).

10. a) Thrombosis of the surgical vascular anastomosis leading to graft ischemia. b) Transplant rejection: Hyperacute, acute, accelerated acute and chronic rejection. c) Recurrent of initial disease in the transplanted kidney like membrano- proliferative glomerulonephritis.

11.  Occurs after very short time of transplantation.  Widespread vascular thrombosis.  Due to pre-formed host antibodies: blood group incompatibility, previous blood transfusions or grafts in host.

12. Subtotal renal infarction due to hyperacute (antibody-mediated) rejection.

13.  Occurs in a patient who has had a previous unsuccessful graft and is therefore already sensitized to donor antigens.

14. Severe acute rejection of donor kidney. Focal infarcts are present.

15. A. Acute cellular rejection : T-cells acting against donor HLA antigens. B. Acute vascular rejection (humoral rejection) : here, there is vasculitis with endothelial cells necrosis and neutrophil infiltration of blood vessels.

16. Acute rejection, Banff Type IA. This category is defined by the presence of an interstitial infiltrate of lymphocytes which moderate tubulitis with greater than four mononuclear cells per tubular-cross section.

17. Acute rejection, Banff Type IB. In this category interstitial infiltrate is more extensive involving greater than 25% of the biopsy with numerous foci of severe tubulitis with greater than 10 mononuclear cells per tubular cross section.

18. Acute rejection. The interstitial infiltrate consists of a mixed population of T cells.

19. Acute rejection, Banff Type IIB. Severity of Type II is determined by the number of vessels involved as well as the intensity of the individual lesions.

20.  Occurs slowly and progressively over a period of few months.  May be due to inadequate immune suppression.  Histopathology shows intimal fibrosis of graft arteries, secondary ischemic changes in parenchyma.  The renal interstitium is infiltrated by plasma cells a lymphocytes.

21. Severe chronic rejection. (graft arteriopathy). Note the severe parenchymal atrophy and the thick-walled arteries.

22. Chronic/ sclerosing allograft nephropathy. An example of Grade II-III is characterized by a diffuse increase in interstitial tissue and marked tubular atrophy as seen on this trichrome stain.

23. Chronic/ sclerosing allograft nephropathy. The classical lesion of chronic transplant vasculopathy is a circumferential proliferation of myointimal cells with an intact internal elastic lamina.