Evaluation of serum MMP-9 as predictive biomarker for antisense therapy in Duchenne.

Duchenne Muscular Dystrophy (DMD) is a severe muscle disorder caused by lack of dystrophin. Predictive biomarkers able to anticipate response to the therapeutic treatments aiming at dystrophin re-expression are lacking. The objective of this study is to investigate Matrix Metalloproteinase-9 (MMP-9) as predictive biomarker for Duchenne.

Analysis of infectious virus clones from two HIV-1 superinfection cases suggests that the primary strains have lower fitness.

Background: Two HIV-1 positive patients, L and P, participating in the Amsterdam Cohort studies acquired an HIV-1 superinfection within half a year from their primary HIV-1 infection (Jurriaans et al., JAIDS 2008, 47:69-73). The aim of this study was to compare the replicative fitness of the primary and superinfecting HIV-1 strains of both patients.

A sudden rise in viral load is infrequently associated with HIV-1 superinfection.

Objective: To investigate the association between an unexpected increase in the blood plasma HIV-1 viral load in chronically untreated HIV-infected patients and the occurrence of an HIV superinfection, we analyzed the HIV-1 quasispecies in plasma samples before and at peak level in 14 patients.

Results: Phylogenetic analysis of HIV-1 env-V3 fragments showed that in 2 patients a superinfection had occurred: their dominant V3 population at the peak level clustered separately from the V3 sequences in a sample predating the peak level. The rapid rise in viral load could be attributed to upper respiratory tract infections or a vaccination in 4 patients, suggesting that even minor health problems can result in significantly increased HIV-1 replication.

HIV-1 sequence evolution in vivo after superinfection with three viral strains.

With millions of people infected worldwide, the evolution of HIV-1 in vivo has been the subject of much research. Although recombinant viruses were detected early in the epidemic, evidence that HIV-1 dual infections really occurred came much later. Dual infected patients, consisting of coinfected (second infection before seroconversion) and superinfected (second infection after seroconversion) individuals, opened up a new area of HIV-1 evolution studies.

Routine HIV-1 genotyping as a tool to identify dual infections.

Objectives: The incidence of HIV-1 dual infections is generally thought to be low, but as dual infections have been associated with accelerated disease progression, its recognition is clinically important. Methods to identify HIV-1 dual infections are time consuming and are not routinely performed.

Design: Genotyping of the HIV-1 protease and reverse transcriptase (prot/RT) genes is commonly performed in the western world to detect drug-resistance mutations in clinical isolates.

An enzyme-linked immunosorbent assay for human cathepsin X, a potential new inflammatory marker.

The human lysosomal cysteine-type carboxypeptidase cathepsin X is mainly present in monocytes and macrophages and may be released into the circulation due to constitutive and/or regulated secretion by (activated) immune cells. To define its potential diagnostic value as an inflammatory marker, we have developed a highly sensitive and specific sandwich-type immunoassay (ELISA) for cathepsin X permitting both intra- and extracellular detection and quantification. The dynamic range of the cathepsin X ELISA was determined to be 100 (detection limit) to 8000 pg/ml.