Immunophenotypic and DNA content characteristics of plasma cells in multiple myeloma and monoclonal gammopathy of undetermined significance

In the present paper we review the immunophenotypic characteristics of plasma cells (PC) and the PC DNA contents from multiple myeloma (MM) and monoclonal gammopathy of undetermined significance (MGUS), and its value for the differential diagnosis between both entities. The strong reactivity for CD38 and the positivity for CD138 are the two best markers for identifying PC. Myelomatous PC display an heterogeneous phenotype consistent with the fact that the neoplastic clone is able to undergo a certain degree of differentiation. In addition, PC from MM patients usually lack surface expression of B-cell associated antigens and frequently display reactivity for markers which are not restricted to the B-cell lineage. In MGUS patients, two clearly defined and distinct PC subpopulations can be identified. One of these PC subpopulations shows phenotypic characteristics identical to those of normal PC, including a very strong reactivity for the CD38 antigen, intermediate/low light scatter characteristics and positivity for CD19, in the absence of CD56, and corresponds to the residual normal bone marrow PC. The second PC subpopulation shows an immunophenotype similar to that of myelomatous PC, characterized by a slightly lower reactivity for CD38 and strong CD56 expression, on the absence of positivity for CD19, these PC corresponding to the clonal counterpart. Using a simultaneous staining for PC and DNA, around 60% of MM and 73% of MGUS patients display DNA aneuploidy, the majority of them being hyperdiploid. However, in contrast to MM patients, in MGUS patients two clearly different PC subsets can be discriminated in most cases (73%): a diploid and an aneuploid (hyperdiploid) subset, corresponding to normal and clonal PC, respectively. Upon comparing hyperdiploid with diploid patients in MM, the former display a better prognosis, in line with the higher incidence of DNA hyperdiploidy in MGUS. A clear correlation between the percentage of S-phase PC and several prognosis features of MM has been found. In spite of these findings, no significant differences in the percentage of pathological S-phase PC are detected between MM and MGUS patients. Regarding the differential diagnosis between MGUS and MM, multivariate analysis shows that the ratio between the number of clonal and normal residual PC is the best single parameter.     

Population study of Aymara Amerindians for the PCR-DNA polymorphisms HUMTH01, HUMVWA31A, D3S1358, D8S1179, D18S51, D19S253, YNZ22 and HLA-DQα

Allele and genotype frequencies for eight DNA polymorphisms (HUMTH01, HUMVWA31A, D3S1358, D8S1179, D18S51, D19S253, YNZ22 and HLA-DQalpha) were determined in a population sample of Aymara Indians from Bolivia using PCR. No deviations of the observed allelic frequencies from Hardy-Weinberg equilibrium were found for all the systems studied. Significant differences in the allele frequencies were found between the Aymara and Quechua populations only for HUMVWA31A, which suggests a certain degree of genetic differentiation between the two populations.     

Acute pancreatitis with fluid collections complicated with cutaneous fistula

The presence of acute fluid collections is an habitual event in an acute pancreatitis, generally followed by a favourable outcome. We present a case about an ancient woman suffering from an acute necrotizing pancreatitis with tense fluid collections that produced espontaneously several cutaneous fistula. We find no report on literature about this uncommon complication. We revised clinical management of acute fluid collections and pancreatic fistulas.     

Beneficial effect of AN69 membranes on anemia in hemodialyzed patients

Biocompatible hemodialysis membranes induce a smaller inflammatory response in hemodialysis patients, and remove a larger amount of higher molecular weight retention products, then cellulose membranes. These phenomena could improve uremic anemia in hemodialysis patients. The objective was to evaluate the effects of biocompatible AN69 membranes on anemia in hemodialysis patients. Twenty-five stable patients undergoing hemodialysis with cuprophane membrane for more than 6 months were studied prospectively. These patients were stratified in 2 groups. Group I (GI): 14 patients switched over to a more biocompatible dialyzer (from cuprophan to AN69) and Group II (GII): 11 patients continued treatment with the same cuprophan membrane. The study lasted 5 months. Baseline hematocrit (%), ferritin (ng/mL), transferrin saturation (%), KTV, PCR (g/kg/day) and dose of erythropoietin (EPO) (UI/week) were measured and were revised monthly. Target hematocrit was 33%-35%. A significant increase of hematocrit became obvious after 2 months in GI without changes in dose of EPO and intensity of dialysis, meanwhile GII remains stable. CONCLUSION: Hemodialysis using AN69 membranes increases hematocrit without modifying intensity of dialysis.     

Acute renal failure in a case of nephrotic syndrome secondary to focal and segmental glomerulosclerosis

Nephrotic syndrome is infrequently complicated with appearance of acute renal failure and minimal change disease is the glomerulopathy more usually involved. Pathogenesis is unclear and three possible mechanisms it has been proposed to explain the decrease of glomerular filtration rate: a severe reduction of glomerular permeability, the presence of acute tubular necrosis or an increased intrarenal pressure related with interstitial oedema. Here we present a 36 years-old-male with a nephrotic syndrome caused by focal and segmental glomerulosclerosis who developed an anuric acute renal failure. Renal function did not change despite oedema removal with haemodialysis and only after corticosteroid and cyclophosphamide therapy introduction we observed a rapid recovery of urinary output and resolution of acute renal failure. Renal biopsy did not show signs of tubular damage or obstruction with proteins nor significant interstitial oedema. Therefore, in this case we think acute renal failure was caused by a severe reduction in glomerular ultrafiltration rate and steroids were the effective treatment that allowed recovery of renal function.