Renal Involvement in Idiopathic Inflammatory Myopathies

Abstract

Renal involvement in idiopathic inflammatory myopathies is not as uncommon as was previously thought, as it develops in about one fifth of patients. Clinical presentation includes either acute kidney injury or chronic glomerulonephritis. The former usually develops abruptly during acute phases of rhabdomyolysis: in this case, kidney injury is caused by the toxic effects that myoglobinuria has on the kidney tubules, including cast formation and iron-induced oxidative stress and the development of a third space into the injured muscles. The latter instead has an autoimmune nature, a pleomorphic histological picture, and a more indolent course, with the exception of crescentic glomerulonephritis. Accurate diagnosis and management is crucial for these patients, as timely evaluation and treatment can prevent most of the complications. In the setting of rhabdomyolysis-induced acute kidney injury, the necessity of dialysis can be avoided through aggressive hydration and alkalinization, in order to force diuresis and avoid acidosis and hyperkalemia. In immune-mediated glomerulonephritis, renal biopsy is of undoubtedly value in the diagnostic process and can add prognostic and therapeutic information. In these forms, the development of chronic kidney disease can be prevented or at least delayed by the institution or modification of immunosuppressive treatment. Moreover, the use of drugs that inhibit the renin-angiotensin-aldosterone system and some lifestyle modifications, such as smoking cessation, weight loss, and salt restriction have also value in reducing proteinuria and the progression of kidney damage. In this review, we have summarized the currently available evidence and the different case series in an attempt to provide the readers with the most complete and practical notions that are needed to handle these delicate patients.

Polymyositis and dermatomyositis – challenges in diagnosis and management

“…Several studies show an increased prevalence of celiac disease in IIM [ 179 , 180 ]. Renal involvement develops in about one fifth of IIM patients [ [181] , [182] , [183] ]. PM and DM are frequently associated with systemic sclerosis and mixed connective tissue disease in the context of an overlap syndrome [ 184 , 185 ].…”

Systemic sclerosis complicated with renal thrombotic microangiopathy: a case report and literature review

“…Thus, based on the renal pathological data, lupus nephritis was not considered. Rhabdomyolysis is a complication of PM, which may lead to acute tubular necrosis with deterioration of renal function [ 10 ]. Both clinical tests and renal biopsy of our case did not support the occurrence of rhabdomyolysis, because no extra-high creatine kinase, myoglobinuria, or tubular casts were shown.…”

The unusual suspects: a curious case of acute kidney injury—Answers

“…The renal effects of JDM and other inflammatory myopathies are not well described, but represent an important consideration in the assessment and management of these patients given the potential for added morbidity and mortality. Rhabdomyolysis is an uncommon manifestation of disease despite potentially chronic muscle inflammation and should be managed similarly to other causes of rhabdomyolysis with treatment of the underlying disturbance and attempt to minimize pigment deposition [8]. Renal sequelae in adult inflammatory myopathies are more common than previously thought with AKI and chronic kidney disease reported in about 20% of patients.…”

“…Renal sequelae in adult inflammatory myopathies are more common than previously thought with AKI and chronic kidney disease reported in about 20% of patients. [8,9] In those with chronic renal sequelae, membranous nephropathy with immune complex deposition was the most common etiology of renal involvement. To the best of our knowledge, oliguric AKI has not been previously reported in juvenile dermatomyositis.…”