Zeroing in on tolerance

A milk-free diet downregulates folate receptor autoimmunity in cerebral folate deficiency syndrome

In cerebral folate deficiency syndrome, the presence of autoantibodies against the folate receptor (FR) explains decreased folate transport to the central nervous system and the clinical response to folinic acid. Autoantibody crossreactivity with milk FR from different species prompted us to test the effect of a milk-free diet. Intervention with a milkfree diet in 12 children (nine males, three females; mean age 6y [SD 4y 11mo], range 1-19y), decreased autoantibody titer significantly from 2.08pmol of FR blocked per ml of serum (SD 2.1; range 0.24-8.35) to 0.35pmol (SD 0.49; range 0-1.32; p=0.012) over 3 to 13 months, whereas FR autoantibody titer increased significantly to 6.53 (SD 6.08; range 0.54-14.07; p=0.013) in nine children who were reexposed to milk for 6 to 14 weeks. In 12 children on a normal diet (eight males, four females; mean age 5y 5mo [SD 4y 1mo], range 1y 6mo-16y 4mo), the antibody titer increased significantly from 0.84pmol of FR blocked per ml (SD 0.39; range 0.24-1.44) to 3.04pmol (SD 1.42; range 0.84-6.01; p=0.001) over 10 to 24 months. Decreasing the autoantibody titer with a milk-free diet in conjunction with folinic acid therapy may be advocated for these patients.

Human foamy virus bel1 sequence in patients with autoimmune rheumatic diseases

Since the association between human foamy virus (HFV) with rheumatic autoimmune diseases remains controversial, this study was designed to determine the relationship between HFV and systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), or progressive systemic sclerosis (PSS). The bel1 and Pol sequences of HFV were measured by reverse transcriptase-polymerase chain reaction (RT-PCR) in plasma and by PCR in peripheral blood mononuclear cells (PBMC) from patients with SLE, RA, and PSS. Antibodies against Bel1 and Pol were assessed by enzyme-linked immunosorbent assay. Active HFV infections were detected by a Bel1-responsive indicator cell line. The bel1 sequence was detected in the plasma (SLE 59, RA 32, and PSS 63%) and PBMC (SLE 54, RA 71, and PSS 57%). However, active HFV infection existed only in patients with the bel1 sequence in both plasma and PBMC. In SLE patients, antibodies against Bel1 (7.1%) and Pol (4.5%) were also detected. The results suggest a possible association between HFV infection and these autoimmune rheumatic diseases.

Genetics of psoriasis: the potential impact on new therapies

There is considerable epidemiologic evidence that genes play a key role in the pathogenesis of psoriasis. It is also clear that multiple genes are involved and that the disease is genetically heterogeneous. Important interactions with the environment are also implicated in its development. A number of genetic loci have been identified by genome wide linkage scans and two loci have been replicated: PSORS1 on chromosome 6, within the major histocompatibility complex, and PSORS2 on chromosome 17q. Understanding the genetic basis of psoriasis will represent a major advance in our understanding of the disease and will reveal novel disease-specific biologic pathways. This information will be used to develop more specific diagnostic and prognostic tools and also lead to the development of individualized treatment plans. Benefits of the latter include more effective and safer treatments and potentially major pharmaco-economic gain.

Aberrant production of IL-12 by macrophages from several autoimmune-prone mouse strains is characterized by intrinsic and unique patterns of NF-kappa B expression and binding to the IL-12 p40 promoter

Intrinsic defects in macrophage (M(phi)) cytokine production characterize many autoimmune-prone mouse strains. Aberrant levels of IL-12, for example, are produced by M(phi) isolated from young mice prone to lupus (MRL and NZB/W) and diabetes (nonobese diabetic (NOD)) well before the appearance of disease signs. Evaluation of the possible mechanism(s) underlying the abnormal regulation of IL-12 in these strains revealed novel patterns of Rel family protein binding to the unique p40 NF-kappaB site in the IL-12 p40 promoter, whereas binding patterns to Ets and CCAAT enhancer binding protein/beta sites were normal. In particular, the heightened production of IL-12 by NOD M(phi) is associated with elevated levels of the trans-activating p50/c-Rel (p65) complex compared with the nonfunctional p50/p50 dimer. Conversely, the dramatically impaired production of IL-12 by both NZB/W and MRL/+ M(phi) is associated with a predominance of p50/p50 and reduced p50/c-Rel(p65) binding. Mechanistically, the unique pattern seen in the lupus strains reflects elevated p50 and reduced c-Rel nuclear protein levels. In NOD extracts, the level of c-Rel is elevated compared with that in lupus strains, but not when compared with that in normal A/J. However, the extent of c-Rel tyrosine phosphorylation noted in NOD extracts is more than double that seen in any other strain. Levels of p65 were similar in all strains tested. These findings reveal that a common mechanism, involving dysregulation of c-Rel and p50, may be used to determine the aberrant IL-12 levels that have the potential to predispose specific mouse strains to systemic or organ-specific autoimmunity.