Overexpression of the major vault transporter protein lung-resistance protein predicts treatment outcome in acute myeloid leukemia

The monoclonal antibody LRP56 recognizes a 110-kD major vault protein (lung-resistance protein [LRP]) overexpressed in several P-glycoprotein- negative (Pgp-), multidrug resistant tumor cell lines. To determine the frequency of LRP overexpression, its prognostic significance, and its relation to Pgp, we analyzed bone marrow specimens from 87 consecutive patients with acute leukemia. Diagnoses included de novo acute myeloid leukemia (AML; 21 patients), leukemia arising from an antecedent hematologic disorder or prior cytotoxic therapy (secondary AML; 27 patients), AML in relapse (29 patients), and blast phase of chronic myeloid leukemia (CML-BP; 10 patients). A granular cytoplasmic staining pattern was detected by immunocytochemistry in 32 (37%) cases, including 7 (33%) de novo AML, 13 (48%) secondary AML, 11 (38%) relapsed AML, and 1 of 10 CML-BP. Among 66 evaluable patients with AML, LRP overexpression was associated with an inferior response to induction chemotherapy (P = .0017). Remissions were achieved in 35% of LRP+ patients as compared with 68% of LRP- patients. Although Pgp adversely affected response in univariate analysis (P = .0414), only LRP had independent prognostic significance when compared in a logistic regression model (P = .0046). Differences in remission duration (P = .075) and overall survival (P = .058) approached significance only for LRP. Sequential specimens from remitting patients receiving treatment with the Pgp modulator cyclosporin-A showed emergence of the LRP phenotype despite a decrease or loss of Pgp at the time of treatment failure (P =.0304). Significant associations were observed between LRP and age greater than 55 years (P = .017), Pgp (P = .040), and prior treatment with mitoxantrone (P = .020) but not with CD34. These findings indicate that overexpression of the novel transporter protein LRP is an important predictor of treatment outcome in AML.     

Trisomy 3 in low-grade B-cell lymphomas of mucosa-associated lymphoid tissue

Characteristic chromosomal aberrations have been associated with subtypes of non-Hodgkin's lymphoma with distinct clinicopathologic features. Low-grade B-cell lymphomas of mucosa-associated lymphoid tissue (MALT) form such a group and might be expected to be characterized by a specific cytogenetic abnormality. Metaphase analyses of MALT lymphoma are rare due to problems with fresh tissue collection and poor in vitro proliferation. However, the small number of published series suggests that chromosome trisomies, particularly trisomy 3, might be characteristic of these tumors. The application of interphase cytogenetic techniques to routinely processed material allows the examination of a large series of archival cases and is particularly useful for the demonstration of chromosome trisomies. We have used this technique to analyze 70 cases of low-grade MALT lymphoma from various sites and found trisomy 3 in 60%. This finding compares with 16% in low- grade nodal B-cell lymphoma and 27% in primary splenic lymphoma of marginal zone type (splenic lymphoma with villous lymphocytes). These results provide further evidence that low-grade MALT lymphomas from all sites form a single pathologic entity distinct from nodal B-cell lymphomas. Although MALT lymphoma and primary splenic lymphoma may arise from marginal zone B cells, they are genetically distinct.     

Column agglutination technology: the antiglobulin test

A new system for typing and screening blood, based on the sieving effect of glass bead microparticles, has been developed. The test is performed in a microcolumn in which the red cell agglutinates are trapped in the glass bead matrix during centrifugation, and unagglutinated cells form a pellet at the bottom of the column. Anti- human globulin reagents were incorporated in the diluent and the new test system, column agglutination technology, was compared to conventional tube tests and low-ionic-strength method. Sera and plasmas (228 samples) were screened for red cell antibodies with two anti-human globulin reagents: one containing only anti-IgG and the other containing both anti-IgG and anti-C3b, -C3d. After initial testing, there was 94-percent agreement between column agglutination technology and tube tests, and after repeat testing, there was 97-percent agreement. The column agglutination technology anti-human globulin test eliminates the need to wash red cells, which decreases the overall test time. The test is easy to perform, and the results are more objective than those with tube and microplate methods.     

Retinal detachment after extracapsular cataract extraction with posterior chamber intraocular lens

The authors reviewed 3065 consecutive cases of extracapsular cataract extraction with posterior chamber lens implant (ECCE-PC IOL) and found the incidence of retinal detachment to be 1.4% overall (44/3065) and 1.7% in a group of eyes followed for at least 1 year (40/2330). Retrospective analysis of the retinal detachment (RD) group (n = 44) showed the patients to be significantly younger than the overall group (n = 3065) (P less than 0.0001). Comparison with an age-matched group of 302 eyes without RD showed higher rates of RD in males (P = 0.0013) and in eyes with axial eye length (AEL) greater than 25 mm (P less than 0.0001). No significant correlation was found between RD and PC IOL manufacturer, phacoemulsification (PKE), or primary discission. Sixty-four percent of RDs occurred within 1 year of cataract operation. Only 10% occurred more than 2 years later. Visual results in eyes with ultimate anatomic success of RD repair (43 of 44 eyes, averaging 15 months follow-up) are substantially better than previously reported in series with other types of IOLs (96% greater than or equal to 20/40 if the macula was not involved, 75% greater than or equal to 20/40 if the macula was involved).