Fungi and paper-based archives. A case report of fungal keratitis in a documentalist

A description of a case is presented on a relationship between paper-based documents as a risk factor for fungal keratitis. A 32-year-old woman, a long-term contact lens user, presented with fungal keratitis in her right eye caused by Fusarium spp. while working with books and old documents as a librarian. Her visual acuity was hand motion in the right eye. She was satisfactorily treated with topical antifungal and antibiotic agents.

Genetic influence of the nonclassical major histocompatibility complex class I molecule MICB in multiple sclerosis susceptibility

It has been widely reported that the major histocompatibility complex (MHC) class II region provides the main genetic contribution to multiple sclerosis (MS) susceptibility. However, recent studies have suggested that the MHC class I region may also contribute to the development of MS. In this study, we investigated the possible association of the human leukocyte antigen (HLA)-B, MHC class I chain-related gene B (MICB) and MHC class I chain-related gene A (MICA) genes, located in the MHC class I region, with MS susceptibility. For this purpose, we analyzed the distribution of HLA-DR, HLA-B, MICB and MICA alleles in 121 MS patients and 156 healthy controls. Neither HLA-B nor MICA alleles were found to be associated with MS susceptibility, and only the frequency of HLA-DRB1*01 allele was found to be increased in controls (31% vs 14%, P(c) = 0.011). However, MICB*004 allele frequency was significantly increased in MS patients (46.3% vs 23.3%, P(c) < 0.001, odds ratio = 2.82, 95% confidence interval = 1.68-4.73). Although, MICB*004 and HLA-DRB1*15 belong to the AH 7.1 ancestral haplotype, the association of MICB*004 to MS susceptibility was found to be independent of HLA-DRB1*15 in our population. This and previous studies clearly suggest that the MHC class I, in addition to class II, could be involved in MS susceptibility.

Clinical behavior of multiple sclerosis is modulated by the MHC class I-chain-related gene A

It is well known that certain HLA class II alleles confer an increased risk for developing multiple sclerosis (MS). Recent studies have suggested HLA class I as a region that may also contribute to the development of MS. In this study, we investigated the association between HLA-DR, HLA-B alleles, and major histocompatibility complex (MHC) class I-chain-related gene A (MICA) transmembrane (MICA-TM) polymorphisms and disease progression in 104 MS patients and 116 healthy controls. DR1 was found to be decreased in patients when compared with controls (p(c) = 0.012). Neither HLA-B nor HLA-DR alleles were found to be associated with MS susceptibility. Furthermore, the prevalence of MICA-A5 in patients with relapsing MS was 9% while the prevalence in progressive forms was 42% (p(c) = 0.0015). The extended haplotypes related to MICA-TM5 that were found in our population were DR7-MICA5-B64 (EH 64.1, delta(s) = 0.38), DR4-MICA5-B62 (EH 62.1, delta(s) = 0.28), and DR11-MICA5-B35 (EH35.1, delta(s) = 0.10), but none of them were found to be associated to MS susceptibility or disease progression. Our data could indicate a possible role of MICA-TM in MS prognosis.

MHC class I chain related gene A (MICA) modulates the development of coeliac disease in patients with the high risk heterodimer DQA1*0501/DQB1*0201

BACKGROUND AND AIMS

Coeliac disease (CD) is an enteropathic disorder characterised by a strong association with major histocompatibility complex (MHC) heterodimer HLA-DQ2. It has been suggested that other HLA class I genes in combination with DQ may also contribute to CD susceptibility. The aim of this study was to investigate whether other candidate genes modify the risk of developing different clinical forms of CD.

PATIENTS AND METHODS

We studied 133 Spanish coeliac patients, divided according to their clinical presentation into typical and atypical groups, and 116 healthy controls. All were typed by polymerase chain reaction-sequence specific primers (PCR-SSP) at HLA-B, DRB1, DQA1, and DQB1 loci and for exon 5 of the MHC class I chain related gene A (MICA).

RESULTS

No differences were found in the frequency of the DQA1*0501/DQB1*0201 heterodimer in either group. The risk of typical CD was significantly associated with the DR7/DQ2 haplotype (p(c)=0.02, odds ratio (OR)=3.4, ethiological fraction (EF)=0.4). Extended haplotype (EH) 8.1 (B8/DR3/DQ2) was found to be overrepresented in the atypical form compared with the typical form (p(c)=0.001, OR=4.19, EF=0.56). The trinucleotide repeat polymorphism MICA-A5.1 was found to be increased in the atypical group of patients compared with the typical group (p(c)=0.00006, OR=8.63, EF=0.81). This association was independent of linkage disequilibrium with EH8.1 as this was also found to be increased in EH8.1 negative atypical patients compared with the typical group (p(c)=0.004, OR=6.66, EF=0.56).

CONCLUSIONS

Our results showed that the risk of developing typical forms of CD was associated with DR7/DQ2 haplotype, and the presence of B8/DR3/DQ2 was significantly increased in atypical patients. In these, the MICA-A5.1 allele confers an additive effect to the DR3/DQ2 haplotype that may modulate the development of CD.

The OTF3 gene polymorphism confers susceptibility to psoriasis independent of the association of HLA-Cw*0602

Psoriasis has been strongly associated to HLA-Cw6, but it remains unclear whether Cw6 itself or a closely linked gene is associated with the disease. The aim of this study was to clarify whether the HLA-C itself determines disease susceptibility or whether it acts only as a marker for the susceptibility allele. We examined a sample of 95 type I psoriasis patients and 104 Spanish matched controls to investigate whether HLA-Cw*0602 or other closely related class I loci, such as HLA-B and MICA (which are centromeric to HLA-C), or corneodesmosin gene and octamer transcription factor-3 genes (which are telomeric to HLA-C), might play a part in disease development. DNA samples were genotyped by polymerase chain reaction/sequence-specific primers (HLA-C), polymerase chain reaction/sequence-specific primers (HLA-B), radioactive polymerase chain reaction (MICA-TM polymorphism in the transmembrane region), and polymerase chain reaction/restriction fragment length polymorphism (protein S and octamer transcription factor-3). Our results show a significant increase of Cw*0602 in psoriasis patients (odds ratio = 3.64; pc < 0.0006). A significant association between the beta allele of octamer transcription factor-3 (HindIII) and psoriasis was also detected (odds ratio = 3.76; pc < 0.0003). The allele octamer transcription factor-3B (etiologic fraction = 0.62) was found to be more strongly associated to psoriasis vulgaris than Cw*0602 (etiologic fraction = 0.35) and the increase of octamer transcription factor-3 B allele is independent of the linkage disequilibrium with Cw*0602 as this was also found in Cw*0602 negative patients (odds ratio = 3.63; pc < 0.015, etiologic fraction = 0.55). We did not detect an association between the corneodesmosin gene and psoriasis. This fact suggests that the psoriasis susceptibility gene is located within a critical region of 147 kb, telomeric to HLA-C and centromeric to the corneodesmosin gene, and the association of Cw6 to psoriasis may be secondary to linkage disequilibrium.