REFRERENCES: Thrombotic Microangiopathic Glomerulitis (TMGL):
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Pham PT, Peng A, Wilkinson AH, Gritsch HA, Lassman C, Pham PC, Danovitch GMCyclosporine and tacrolimus-associated thrombotic microangiopathy. Am J Kidney Dis 2000 Oct;36(4):844-50 The development of thrombotic microangiopathy (TMA) associated with the use of cyclosporine has been well documented. Treatments have included discontinuation or reduction of cyclosporine dose with or without concurrent plasma exchange, plasma infusion, anticoagulation, and intravenous immunoglobulin G infusion. However, for recipients of organ transplantation, removing the inciting agent is not without the attendant risk of precipitating acute rejection and graft loss. The last decade has seen the emergence of tacrolimus as a potent immunosuppressive agent with mechanisms of action virtually identical to those of cyclosporine. As a result, switching to tacrolimus has been reported to be a viable therapeutic option in the setting of cyclosporine-induced TMA. With the more widespread application of tacrolimus in organ transplantation, tacrolimus-associated TMA has also been recognized. However, literature regarding the incidence of the recurrence of TMA in patients exposed sequentially to cyclosporine and tacrolimus is limited. We report a case of a living donor renal transplant recipient who developed cyclosporine-induced TMA that responded to the withdrawal of cyclosporine in conjunction with plasmapheresis and fresh frozen plasma replacement therapy. Introduction of tacrolimus as an alternative immunosuppressive agent resulted in the recurrence of TMA and the subsequent loss of the renal allograft. Patients who are switched from cyclosporine to tacrolimus or vice versa should be closely monitored for the signs and symptoms of recurrent TMA.
McLigeyo SO: Haemolytic uraemic syndrome: a review. East Afr Med J 1999 Mar;76(3):148-53 OBJECTIVES: To provide an overview of the current understanding of the classification of haemolytic uraemic syndrome (HUS) and to describe the epidemiology, pathogenesis, clinical picture, renal histopathological findings, treatment and prevention of shiga toxin (Stx)-associated HUS, the most common type of HUS and; to compare and contrast features of idiopathic (atypical) HUS and inherited HUS with those of Stx-associated HUS. DATA SOURCE: A literature review was performed of major published series between 1989 and 1998 inclusive, using the Index Medicus and MEDLINE search. Some earlier published series were also reviewed in instances where they indirectly led to the current studies or reported on rarer organ involvements in HUS. STUDY SELECTION: Data and opinions from twelve general reviews of HUS, twelve on aetiology and classification, twelve on clinical features, eight on pathogenesis and nine on treatment and prognosis are summarised. CONCLUSION: HUS is a thrombotic microangiopathy with several aetiologies currently thought to play a role. Vascular endothelial cell injury appears to be central to the pathogenesis of all forms of HUS, although the triggering factors may be different and not well understood in some cases. In HUS, supportive therapy is of paramount importance. Reported specific therapies do not have sufficient evidence to support them. Prevention of HUS is possible in Stx-associated form, but not in the others. In patients who go on to develop end-stage renal failure, transplantation is possible, but recurrence rates are high in forms other than those which are Stx-associated. Persisting sequelae in other organs in HUS are infrequent.
Katoh M, Shigematsu H: Renal involvement of thrombotic thrombocytopenic purpura: special reference to the glomeruloid structures. Pathol Int 1999 Jul;49(7):638-42 We report the case of a 9-year-old girl with biopsy-proven renal thrombotic microangiopathy in thrombotic thrombocytopenic purpura (TTP), with particular reference to the glomeruloid structures. The renal biopsy sample from this TTP patient revealed platelet thrombus deposition, a glomeruloid structure and aneurysm with relative sparing of the glomeruli. The glomeruloid structure displayed a proliferation of mainly capillary-sized channels lined by Factor VIII-related, antigen-positive plump endothelial cells embedded in the edematous connective tissue. These glomeruloid vessels communicated with the aneurysmal segment at the end portion of the arteriolar branch. We believe that the glomeruloid structures in TTP represent not merely organization or recanalization of thrombus but rather active angiogenesis through aneurysmal dilation in the arteriolized vessel, probably initiated by platelet agglutination.
Griffiths MH, Papadaki L, Neild GH: The renal pathology of primary antiphospholipid syndrome: a distinctive form of endothelial injury. QJM 2000 Jul;93(7):457-67 Some features of the vascular and glomerular pathology of primary antiphospholipid syndrome (APS) are well recognized, but we describe novel glomerular ultrastructural changes that we consider to be pathognomonic of APS. Renal biopsies from eight patients with APS were examined by light and electron microscopy. All had anti-cardiolipin antibodies, and the clinical presentation ranged from fulminant multi-system disease to isolated proteinuria. By light microscopy, the hexamine silver stain showed a combination of glomerular basement membrane wrinkling and reduplication. By electron microscopy, redundant, wrinkled segments of basement membrane were accompanied by a 'new' straighter thin basement membrane adjacent to the endothelium. In two cases the presence of these antibodies was not suspected clinically, and there was no clinical history or evidence of a thrombotic microangiopathy. We describe a distinctive glomerular lesion that represents an unexplained form of endothelial injury in this syndrome.
Gal, Anthony A, Velasquez, A: Antineutrophil Cytoplasmic Autoantibody in the absence of Wegener's granulomatosis or microscopic polyangiatis: Implications for the Surgical Pathologist. Mod Pathol2002;15(3):197-204.