Multiple myeloma

Renal failure - a dangerous complication of multiple myeloma. It is found in half of all patients at the time of diagnosis and is second after infection leading cause of death [DeFronzo et al., 1978; Kyle, 1975]. According to a study conducted by the Medical Research Council, renal function is an important single factor determining the prognosis of the disease, showed that mortality among patients with levels of blood urea to 12 mmol / L were 5 times higher than among patients with normal value of this rate at the time of diagnosis [Galton et al., 1973]. The basis of renal dysfunction in myeloma may be based on a variety of different mechanisms leading to acute or chronic renal failure, nephrotic syndrome (usually in combination with amyloidosis), or occasionally - to the Fanconi's anemia. Of particular importance in the pathogenesis of renal lesions attached easily avoidable disturbances, such as hypercalcemia, hyperuricemia, and increased blood viscosity [Cohen, Rundles, 1975]. Increased serum levels of calcium or uric acid can certainly be associated with acute renal failure, and vomiting and polyuria, associated hypercalcemia, increase water loss due to a direct violation of its tubular reabsorption. Because of dehydration and related hypertonic blood introduction so sick of contrast medium for intravenous urography is contraindicated [Cohen, Rundles, 1975].

Cause of progressive viagra san antonio chronic renal failure, so often observed in multiple myeloma, remains controversial. Reported a clear relationship between impaired renal function and urinary excretion of light chain paraprotein [DeFronzo et al., 1978], but this observation is not confirmed by all investigators [Kyle, Elveback, 1976]. Of the 35 patients studied, all of 9 without proteinuria Bence-Jones creatinine clearance (KKR) was above 50 ml / min. More than half of patients with Bence-Jones proteinuria KKR was below 50 ml / min. Severity of urinary light chains correlated with the degree of renal failure [DeFronzo et al., 1978]. The majority of patients with a daily excretion of Bence-Jones protein above 1 g, severe renal insufficiency (mean KKR was 8 ml / min). A similar relationship was found in the first study, conducted by the Medical Research Council [Galton et al., 1973].

The assumption that the blockade of the tubules as a result of deposits of paraprotein Bence-Jones now looks doubtful, since some patients with very high levels of urinary light chains of renal function remain normal. In addition, histological examinations of renal biopsies showed that in the case of cylinders the past consist of albumin, immunoglobulin light chains and a mixture of X and X, and that marked impairment of renal function may occur in the absence of tubular cylinders [Kyle, Bayrd, 1976]. Severe atrophy of tubules - a sign of pathology, the most correlated with the clinical manifestations of "myeloma kidney". Light chains are metabolized in the cells of the tubules, providing them direct toxic effect [DeFronzo et al., 1978].

The pH of urine can be shifted to the alkaline side, may also be impaired renal concentrating ability. Occasionally, when myeloma occurs Fanconi's anemia [Maldonado et al., 1975]. In all these cases, the patient was revealed Bence-Jones proteinuria, and the diagnosis of multiple myeloma for several years, sometimes preceded by a dysfunction of proximal tubules.

In one survey [Kyle, 1975] in 7% of cases detected renal amyloidosis, which could well be the cause of the nephrotic syndrome or renal failure. Urinary tract infection is rarely the primary cause of kidney failure, but aggravates the already existing kidney failure.