Important Nephrology Situations: Renal Lesions In Systemic Diseases
Diabetes Mellitus, SLE And Rheumatoid Arthritis
There are some systemic diseases which could affect the Kidney as well. Such ailments are: Diabetes mellitus, systemic lupus erythematosus (SLE), rheumatoid arthritis, polyarteritis nodosa, renal tuberculosis, gout and infective endocarditis.
Diabetes Mellitus: Renal involvement is common in patients suffering from diabetes mellitus for 15 years or more. All parts of the kidney may be affected. Accelerated atherosclerosis in the renal blood vessels may result in hypertension. Recurrent attacks of urinary tract infection are common. Renal papillary necrosis is a rare complication usually following severe urinary tract infections. The renal papillae slough off and are shed into the renal pelvis. This may result in obstruction to the ureter and the development of pyonephrosis. Rarely these fleshy bits may appear in urine which is blood-stained. Management consists of appropriate treatment of diabetes mellitus and antibiotics to control infection.
Diabetic nephropathy which develops in many cases of long standing diabetes is characterized initially by asymptomatic proteinuria which gradually increases over many years and leads to nephrotic syndrome, hypertension and renal failure. The histological changes include diffuse or nodular glomerulosclerosis. There is no known therapy which can reverse diabetic nephropathy once it is established. It is the general belief, however that if the diabetes is meticulously controlled, the onset of nephropathy and other degenerative complications can be delayed. Adequate control of hypertension and diabetes help in retarding the rate of progression of these complications.
Systemic lupus erythematosus (SLE): Renal involving is common in SLE and it accounts for a high proportion of the morbidity and mortality. It may manifest as acute nephritic syndrome, nephrotic syndrome, asymptomatic urinary abnormalities, acute renal failure and chronic renal failure. Different types of glomerular and tubular lesions are seen and these are caused by the deposition of immune complexes. Treatment is for the underlying condition with corticosteroids and immunosuppressant drugs.
Rheumatoid Arthritis: Immune complex-mediated glomerular damage is seen in some cases of rheumatoid arthritis. Other lesions include vasculitis and drug-induced renal damage caused by the antihrheumatic drugs.
Gout And Hyperuricemia
Renal Tuberculosis, Infective Endocarditis And Others
Polyarteritis nodosa: The renal involvement may manifest clinical as acute oliguric renal failure, hypertension, proteinuria or hematuria. The lesions involved the arcuate arteries leading to development of aneurysms. The glomerular involvement may be in the form of crescentic glomerulonephritis and necrosis of parts of the glomerular capillary.
Renal tuberculosis: Involvement of the kidney and the urinary tract is common in tuberculosis. Clinical manifestations include frequency of micturition, irregular fever, sterile pyuria (pus in urine but repeated cultures), loin pain and painless hematuria. Tuberculous epididymitis should raise the possibility of renal tuberculosis, M. tuberculosis may be demonstrable in urine, and the organisms can be isolated by culture in special media. Plain X-ray may reveal enlargement of the kidney or calcification. Intravenous urogram shows distortion of the calyces. Cystoscopy may reveal tubercles around the ureter. Advanced tuberculosis may lead to destruction of the kidney. This may lead to secondary hypertension.
Gout and hyperuricemia: An abrupt and massive increase of plasma uric acid occurring during the therapy of malignant diseases may lead to the precipitation of uric acid crystals in the renal tubules and urinary tract, especially when the urine is acidic in reaction and there is oliguria. Acute urate nephropathy manifests as acute renal failure. Adequate fluid intake to ensure urine volume of 2- 2.5 liters/day and administration of sodium citrate or bicarbonate to render the urine alkaline, reduce the risk of crystalluria and obstruction. Allopurinol given in a dose of 100 mg thrice a day orally reduces the formation of uric acid.
The clinical picture of chronic gouty nephropathy is that of chronic renal failure.
Infective endocarditis: Persistent infection with streptococcus viridians and coagulase positive Staphylococcus aureus produce a type of immune complex glomerulonephritis which may present as microscopic hematuria, acute nephritic syndrome, crescentic glomerulonephritis or nephrotic syndrome. Elimination of infection by appropriate antibiotic therapy is the most effective step in relieving this condition.
© 2014 Funom Theophilus Makama