Estudo da albuminuria em pacientes com diagnostico de mieloma multiplo

AUTOR(ES)
DATA DE PUBLICAÇÃO

2002

RESUMO

Renal dysfunction in patients with multiple myeloma (MM) is, in most cases, a consequence of tubulointerstitial alterations caused by the excessive presence of light chains in the glomerular filtrate, that ftequently results in increased urinary excretion of tubularproteins, such as alpha 1microglobulin. The presence small amounts ofalbuminuria has also been observed in this patients and is attributed to the competition for absorptive sites in the proximal tubules. The less frequent glomerular disease in these patients is usually caused by amiloidosis or light chain disease and, despite of the presence o macroalbuminuria, frequently the patient is referred to the nephrologist in presence of advanced renal damage with nephritic syndrome or renal failure. This study was divided in two parts: the retrospective study included 68 patients with MM, followed at our outclinics, in order to compare the clinical and laboratory data with previous reports. We also analysed the urinary excretion of alpha 1 microglobulin, albumin and light chains during the MM treatment, in a prospective group of 17 patients. Results: Retrospective study - Included 2 groups of patients, Group I (n=41) with serum creatinine - 1,2 mgldL and Group II (n=27) with serum creatinine >1,2 mgldL. We observed, in the group of patients that presented reduction of renal function at diagnosis, a more frequent proteinuria and higher calcemia, both associated with loss of renas function. The younger patients presented a higher tendency to recovery of renal function. Albuminuria was found in the majorityof patients, independently ofthe initial serum creatinine levels. Prospective study - During a period of 18months, excretion of albumin, alpha 1microglobulin and light chains in serial urine samples ftom 17 patients with MM diagnosis and serum creatinine <1,2 mgldL were analysed. A positive correlation between the urinary excretion oflight chains &albumin (p= 0.006), light chains &alpha 1 microglobulin (p=O.003) and albumin &alpha 1 microglobulin (p=0.0002)was observed in this group. In conclusion,in the present study albuminuria was a frequent finding, independently of the creatinine levels. In patients with creatinine lower than 1,2 mgldL, decrease in urinary light chains excretion was followed by a decrease in urinary albumin and alpha 1 microglobulin. This outcome suggests that in presence of subtle glomerulopathy and/or tubulopathy in MM,the decrease in light chain excretion do not present a parallel decrease of urinary albumin and/or of alpha 1 microglobulin.

ASSUNTO(S)

albuminuria rins - doenças mieloma multiplo

ACESSO AO ARTIGO

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