Bronchiolitis obliterans with organizing pneumonia (BOOP) heralding anti-Jo-1-positive polymyositis.

We report a 51-year-old man who presented with 3 weeks of polyarthritis with fever, nonproductive cough, bibasilar crackles, tachypnea, and hypoxia. Initial laboratory data showed an increased erythrocyte sedimentation rate, rheumatoid factor, and anti-Jo-1 antibody. Imaging studies showed bilateral lower lobe infiltrates of the lung. A transbronchial biopsy specimen revealed characteristic findings for bronchiolitis obliterans organizing pneumonia (BOOP). About 6 months later, he developed profound proximal muscle weakness with a dramatic increase in creatine phosphokinase and aldolase and a further elevation of anti-Jo-1. Muscle biopsy specimen findings were consistent with polymyositis.This represents an unusual case in which BOOP occurred at the onset of an illness initially suggestive of rheumatoid arthritis (RA). The anti-Jo-1-positivity led to close follow up and later discovery of evolution into polymyositis. BOOP can be an early feature of polymyositis as well as RA.

Genetic variability in HIV-1 gp120 affects interactions with HLA molecules and T cell receptor.

The propensity of HIV-1 to undergo sequence variation, particularly in the envelope glycoprotein gp120, complicates vaccine development and may enable the virus to evade ongoing immune responses in infected individuals. We present here a molecular analysis of the effects of this variability on human T cell recognition of HIV-1 gp120. Synthetic peptides representing a defined CD4+ human T cell epitope in gp120 were used to survey gp120 molecules from various HIV-1 strains for the capacity to be recognized in the context of a single human MHC molecule, DR4. Variation affected recognition at two levels. For some strains, variation in this epitope was sufficient to alter the interaction of Ag receptors on gp120-specific human T cell clones with peptide-DR4 complexes on APC. In the case of two strains, the natural variation was sufficient to prevent the critical initial interaction between the relevant gp120 peptides and DR4 on the APC. However, these strains were highly divergent from the reference strain. Thus it is encouraging to note that the range of natural sequence variation in this T cell epitope falls, for the most part, within the range of peptide sequences that can be accommodated by the relevant human MHC molecule.