HIV-infected individuals on long-term antiretroviral therapy are at higher risk for ocular disease.

Introduction of antiretroviral therapy (ART) has dramatically reduced the incidence of infectious ocular diseases in human immunodeficiency virus (HIV)-infected individuals. However, the effects of long-term ART and chronic HIV infection on the eye are ill-defined. This study determined the occurrence and severity of ocular diseases among 342 participants in a rural South African setting: HIV-naïve (n = 105), HIV-infected ART-naïve (n = 16), HIV-infected on ART for 36 months (long-term ART; n = 165). More HIV-infected participants presented with an external eye condition, in particular blepharitis, than HIV-naïve individuals (18% vs. 7%; age-adjusted odds ratio (aOR) = 2·8, P < 0·05). Anterior segment conditions (particularly keratoconjunctivitis sicca and pterygium) were also more common (50% vs. 27%; aOR = 2·4; P < 0·01). Compared with individuals on short-term ART, participants receiving long-term ART were more likely to have clinically detectable cataract (57% vs. 38%; aOR = 2·2, P = 0·01) and posterior segment diseases, especially HIV retinopathy (30% vs. 11%; aOR = 3·4, P < 0·05). Finally, long-term ART was significantly associated with presence of HIV retinopathy (P < 0·01). These data implicate that ocular disease is more common and of more diverse etiology among HIV-infected individuals, especially those on long-term ART and suggest that regular ophthalmological monitoring of HIV-infected individuals on ART is warranted.

European consensus-based (S2k) Guideline on the Management of Herpes Zoster - guided by the European Dermatology Forum (EDF) in cooperation with the European Academy of Dermatology and Venereology (EADV), Part 2: Treatment.

Herpes zoster (HZ, shingles) is a frequent medical condition which may severely impact the quality of life of affected patients. Different therapeutic approaches to treat acute HZ are available. The aim of this European project was the elaboration of a consensus-based guideline on the management of patients who present with HZ, considering different patient populations and different localizations. This interdisciplinary guideline aims at an improvement of the outcomes of the acute HZ management concerning disease duration, acute pain and quality of life of the affected patients and at a reduction in the incidence of postherpetic neuralgia (PHN) and other complications. The guideline development followed a structured and pre-defined process, considering the quality criteria for guidelines development as suggested by the AGREE II instrument. The steering group was responsible for the planning and the organization of the guideline development process (Division of Evidence-Based Medicine, dEBM). The expert panel was nominated by virtue of clinical expertise and/or scientific experience and included experts from the fields of dermatology, virology/infectiology, ophthalmology, otolaryngology, neurology and anaesthesiology. Recommendations for clinical practice were formally consented during the consensus conference, explicitly considering different relevant aspects. The guideline was approved by the commissioning societies after an extensive internal and external review process. In this second part of the guideline, therapeutic interventions have been evaluated. The expert panel formally consented recommendations for the treatment of patients with HZ (antiviral medication, pain management, local therapy), considering various clinical situations. Users of the guideline must carefully check whether the recommendations are appropriate for the context of intended application. In the setting of an international guideline, it is generally important to consider different national approaches and legal circumstances with regard to the regulatory approval, availability and reimbursement of diagnostic and therapeutic interventions.

European consensus-based (S2k) Guideline on the Management of Herpes Zoster - guided by the European Dermatology Forum (EDF) in cooperation with the European Academy of Dermatology and Venereology (EADV), Part 1: Diagnosis.

Herpes zoster (HZ, shingles) is a frequent medical condition which may severely impact the quality of life of affected patients. Different therapeutic approaches to treat acute HZ are available. The aim of this European project was the elaboration of a consensus-based guideline on the management of patients who present with HZ, considering different patient populations and different localizations. This interdisciplinary guideline aims at an improvement of the outcomes of the acute HZ management concerning disease duration, acute pain and quality of life of the affected patients and at a reduction of the incidence of postherpetic neuralgia and other complications. The guideline development followed a structured and predefined process, considering the quality criteria for guidelines development as suggested by the AGREE II instrument. The steering group was responsible for the planning and the organization of the guideline development process (Division of Evidence based Medicine, dEBM). The expert panel was nominated by virtue of clinical expertise and/or scientific experience and included experts from the fields of dermatology, virology/infectiology, ophthalmology, otolaryngology, neurology and anaesthesiology. Recommendations for clinical practice were formally consented during the consensus conference, explicitly considering different relevant aspects. The guideline was approved by the commissioning societies after an extensive internal and external review process. In this first part of the guideline, diagnostic means have been evaluated. The expert panel formally consented recommendations for the management of patients with (suspected) HZ, referring to the assessment of HZ patients, considering various specific clinical situations. Users of the guideline must carefully check whether the recommendations are appropriate for the context of intended application. In the setting of an international guideline, it is generally important to consider different national approaches and legal circumstances with regard to the regulatory approval, availability and reimbursement of diagnostic and therapeutic interventions.

Clinical and corneal microbial profile of infectious keratitis in a high HIV prevalence setting in rural South Africa.

The purpose of this investigation was to determine the clinical and corneal microbial profile of infectious keratitis in a high human immunodeficiency virus (HIV) prevalence setting in rural South Africa. Data in this cross-sectional study were collected from patients presenting with symptoms of infectious keratitis (n = 46) at the ophthalmology outpatient department of three hospitals in rural South Africa. Corneal swabs were tested for herpes simplex virus type 1 (HSV-1) and 2 (HSV-2), varicella zoster virus (VZV) and adenovirus DNA by real-time polymerase chain reaction (PCR) and for bacteria and fungi by culture. Based on clinical history, disease characteristics and laboratory results, 29 (63 %) patients were diagnosed as viral keratitis, including 14 (48 %) viral keratitis cases complicated by bacterial superinfection, and 17 (37 %) as bacterial keratitis. VZV and HSV-1 DNA was detected in 11 (24 %) and 5 (11 %) corneal swabs, respectively. Among clinically defined viral keratitis cases, a negative viral swab was predominantly (93 %) observed in cases with subepithelial inflammation and was significantly associated with an increased duration of symptoms (p = 0.003). The majority of bacteria cultured were Gram-positive (24/35), including Staphylococcus epidermidis and S. aureus. Viral aetiology was significantly associated with a history of herpes zoster ophthalmicus (p < 0.001) and a trend was observed between viral aetiology and HIV infection (p = 0.06). Twenty-one (47 %) keratitis cases were complicated by anterior uveitis, of which 18 (86 %) were HIV-infected cases with viral keratitis. The data implicate a high prevalence of herpetic keratitis, in part complicated by bacterial superinfection and/or uveitis, in HIV-infected individuals presenting with infectious keratitis in rural South Africa.

CD4 T-cell memory responses to viral infections of humans show pronounced immunodominance independent of duration or viral persistence.

Little is known concerning immunodominance within the CD4 T-cell response to viral infections and its persistence into long-term memory. We tested CD4 T-cell reactivity against each viral protein in persons immunized with vaccinia virus (VV), either recently or more than 40 years ago, as a model self-limited viral infection. Similar tests were done with persons with herpes simplex virus 1 (HSV-1) infection as a model chronic infection. We used an indirect method capable of counting the CD4 T cells in blood reactive with each individual viral protein. Each person had a clear CD4 T-cell dominance hierarchy. The top four open reading frames accounted for about 40% of CD4 virus-specific T cells. Early and long-term memory CD4 T-cell responses to vaccinia virus were mathematically indistinguishable for antigen breadth and immunodominance. Despite the chronic intermittent presence of HSV-1 antigen, the CD4 T-cell dominance and diversity patterns for HSV-1 were identical to those observed for vaccinia virus. The immunodominant CD4 T-cell antigens included both long proteins abundantly present in virions and shorter, nonstructural proteins. Limited epitope level and direct ex vivo data were also consistent with pronounced CD4 T-cell immunodominance. We conclude that human memory CD4 T-cell responses show a pattern of pronounced immunodominance for both chronic and self-limited viral infections and that this pattern can persist over several decades in the absence of antigen.

Quantification of viral DNA and liver enzymes in plasma improves early diagnosis and management of herpes simplex virus hepatitis.

Herpes simplex virus (HSV) hepatitis is a rare and potential life-threatening disease. The diagnosis of HSV hepatitis is hampered by its indifferent clinical presentation, which necessitates confirmatory laboratory data to identify HSV in the affected liver. However, liver biopsies are often contraindicated in the context of coagulopathy, are prone to sampling errors and have low sensitivity in mild HSV hepatitis cases. There is an unmet need for less invasive diagnostic tools. The diagnostic and therapeutic value of HSV DNA load and liver enzyme level kinetics was determined in five patients with HSV hepatitis and twenty disease controls with HSV-DNAemia without hepatitis. At time of hospitalization, patients with HSV hepatitis had a higher median (± interquartile range) HSV DNA load (6.0 × 10(6) ± 1.2 × 10(9)) compared to disease controls (171 ± 2845). Viral DNA load correlated with liver transaminase levels and disease severity. Antiviral treatment led to rapid decline of HSV DNA load and improvement of liver function of patients with HSV hepatitis. The data advocate the prompt and consecutive quantification of the HSV DNA load and liver enzyme levels in plasma of patients suspected of HSV hepatitis as well as those under antiviral treatment.

Prevalence of herpes simplex virus type 1 glycoprotein G (gG) and gI genotypes in patients with herpetic keratitis.

AIM: Recent phylogenetic analyses on the herpes simplex virus type 1 (HSV-1) genes US4, encoding glycoprotein G (gG) and US7, encoding gI, of clinical HSV-1 isolates have led to the classification of HSV-1 into three genotypes, arbitrarily designated as A, B and C. The prevalence of the HSV-1 gG and gI genotypes and their potential disease association was determined in a large cohort of patients with herpetic keratitis (HK). METHODS: Primary corneal HSV-1 isolates of 178 HK patients were genotyped by a PCR-based restriction fragment length polymorphism method targeting the viral genes US4 and US7. RESULTS: Genotype B was more frequently expressed by the corneal HSV-1 isolates compared with genotypes A and C. Fifty-five of 178 corneal isolates (31%) had different genotypes in both loci. No clinically relevant associations were observed between the HSV-1 genotypes and disease outcome in the HK patients studied. CONCLUSIONS: The data presented demonstrate a high frequency of recombinant corneal HSV-1 isolates and suggest that clinical outcome of HSV-1-induced keratitis is independent of a gG or gI genotype.

Imbalances in circulating lymphocyte subsets in Hu antibody associated paraneoplastic neurological syndromes.

In paraneoplastic neurological syndromes (PNS) associated with small cell lung cancer (SCLC) and Hu antibodies, neuron-specific Hu antigens expressed by the tumour hypothetically trigger an immune response that cross-reacts with Hu antigens in the nervous system, resulting in tumour suppression and neuronal damage. To gain more insight into the hypothesized cell-mediated immune pathogenesis of these syndromes, we analysed the circulating lymphocyte subsets in untreated patients with SCLC, PNS and Hu antibodies (n = 18), SCLC without PNS (n = 19) and controls (n = 29) using flow cytometry. SCLC patients with PNS had a variety of imbalances within their circulating lymphocyte subsets as compared with SCLC patients without PNS and healthy controls: (i) a lymphopenia of the major subsets (i.e. B, CD4+ and CD8+ T lymphocytes); (ii) increased proportions of activated CD4+ and CD8+ T cells; (iii) reduced numbers of terminally differentiated effector CD8+ T cells and cells with a cytotoxic T-cell phenotype (CD56+ and CD57+). Although indirect, our data provide further support for the involvement of T cells in the pathogenesis of Hu antibody associated PNS.

Identification of a common HLA-DP4-restricted T-cell epitope in the conserved region of the respiratory syncytial virus G protein.

The cellular immune response to respiratory syncytial virus (RSV) is important in both protection and immunopathogenesis. In contrast to HLA class I, HLA class II-restricted RSV-specific T-cell epitopes have not been identified. Here, we describe the generation and characterization of two human RSV-specific CD4(+)-T-cell clones (TCCs) associated with type 0-like cytokine profiles. TCC 1 was specific for the matrix protein and restricted over HLA-DPB1*1601, while TCC 2 was specific for the attachment protein G and restricted over either HLA-DPB1*0401 or -0402. Interestingly, the latter epitope is conserved in both RSV type A and B viruses. Given the high allele frequencies of HLA-DPB1*0401 and -0402 worldwide, this epitope could be widely recognized and boosted by recurrent RSV infections. Indeed, peptide stimulation of peripheral blood mononuclear cells from healthy adults resulted in the detection of specific responses in 8 of 13 donors. Additional G-specific TCCs were generated from three of these cultures, which recognized the identical (n = 2) or almost identical (n = 1) HLA-DP4-restricted epitope as TCC 2. No significant differences were found between the capacities of cell lines obtained from infants with severe (n = 41) or mild (n = 46) RSV lower respiratory tract infections to function as antigen-presenting cells to the G-specific TCCs, suggesting that the severity of RSV disease is not linked to the allelic frequency of HLA-DP4. In conclusion, we have identified an RSV G-specific human T helper cell epitope restricted by the widely expressed HLA class II alleles DPB1*0401 and -0402. Its putative role in protection and/or immunopathogenesis remains to be determined.

Seal gammaherpesviruses: identification, characterisation and epidemiology.

Phocid herpesvirus type 2 (PhHV-2), tentatively classified as a gammaherpesvirus, has been isolated from European and American harbour seals (Phoca vitulina). Here we describe the isolation and the molecular as well as biological characterisation of different PhHV-2 isolates from harbour seals and grey seals (Halichoerus grypus). Of 522 harbour seals and 231 grey seals that had been admitted to the seal research and rehabilitation centre in Pieterburen, The Netherlands, between 1992 and 2000, 38 and 18%, respectively, proved to have PhHV-2 neutralising antibodies. PhHV-2 was isolated from peripheral blood mononuclear cells (PBMCs) of 12 and 28% of these seropositive animals, respectively, and 26 and 56% of these cell samples, respectively, were positive by PCR analysis. Analysis of amino acid sequences of PCR products and of the growth characteristics of different PhHV-2 isolates indicated that harbour and grey seals are infected with distinct gamma-herpesviruses, which however, may co-circulate between the two species.

Characterization of Toxoplasma gondii-specific T cells recovered from vitreous fluid of patients with ocular toxoplasmosis.

PURPOSE: The mechanisms involved in reactivations of latent ocular Toxoplasma gondii (Tg) infections in immunocompetent patients are poorly understood. In view of the possible role of T cells in the immunopathogenesis of the disease, ocular infiltrating T cells obtained from patients with recurrent ocular toxoplasmosis were characterized phenotypically and functionally. METHODS: Ocular infiltrating T cells were recovered from vitreous fluid (VF) samples of 10 patients with active recurrent ocular toxoplasmosis. Two patients with uveitis of other origins were included as control subjects. T-cell lines (TCLs) were generated by mitogenic stimulation and tested for reactivity to Tg and human retinal protein extracts. The TCLs of three patients were cloned by limiting dilution. Tg-reactive T-cell clones (TCCs) were characterized with respect to their phenotype, T-cell receptor variable (TCR V)-beta gene usage, HLA restriction, and cytokine secretion profile. RESULTS: Reactivity to Tg could be detected only in the TCLs of patients with ocular toxoplasmosis. None of the TCLs showed reactivity to human retinal antigens. All tested intraocular Tg-specific TCCs (n = 23) were CD3+CD4+ and displayed differential TCR Vbeta usage. Twenty-one TCCs were HLA-DR restricted and two TCCs were restricted by HLA-DP. The majority of the intraocular Tg-specific TCCs showed a bias toward a T-helper (Th)0-Th2 cytokine profile. CONCLUSIONS: The data indicate that T cells specific for the triggering microorganism infiltrate the eye of patients with recurrent ocular toxoplasmosis. The functional characteristics of the VF-derived Tg-specific T cells and their presence at the site of inflammation suggest their involvement in the local inflammatory response of ocular toxoplasmosis.

Prevalence and association between herpes simplex virus types 1 and 2-specific antibodies in attendees at a sexually transmitted disease clinic.

BACKGROUND: Seroprevalence of herpes simplex virus type 1 (HSV-1) and HSV-2 was determined in 1993 and 1998 in a randomly selected study group of 1024 and 654 attendees, respectively, at the sexually transmitted disease (STD) clinic of the University Hospital Rotterdam-Dijkzigt, The Netherlands. Correlations of HSV-1 and HSV-2 seropositivity were investigated. The relationship between HSV-1 and HSV-2 antibodies was also studied. METHODS: Data were collected in a cross-sectional study from February 1993 until February 1994 and from January 1998 until December 1998. Glycoprotein G (gG) HSV type specific serum IgG was determined. RESULTS: Seroprevalence of HSV-1 was 68% versus 59% (1993 versus 1998, chi(2)-test P < 0.001), of HSV-2 it was 30% versus 22% (1993 versus 1998, chi(2)-test P < 0.001). Using logistic regression analyses, HSV-1 and HSV-2 seropositivity were significantly associated with age and ethnicity in both groups. In 1993, HSV-1 seropositivity also correlated with lower level of education and female gender, whereas in 1998 it correlated with 'number of sexual partners in the past 6 months' and 'present diagnosis of STD'. In both groups, HSV-2 seropositivity was also more prevalent in females and related to sexual lifestyle variables. In an exposure-disease model, HSV-1 seropositivity was not correlated with HSV-2 seropositivity (odds ratio 1993 = 1.1, 95% CI : 0.8--1.7; odds ratio in 1998 = 1.0, 95% CI : 0.5--1.8). CONCLUSIONS: Seroprevalence of HSV-1 and HSV-2 is falling among STD clinic attendees in Rotterdam. A changing pattern of risk factors for HSV-1 seropositivity indicates increasing sexual transmission of HSV-1. Seropositivity for HSV-2 correlated with known risk factors. A previous HSV-1 infection does not reduce susceptibility to subsequent genital HSV-2 infections.

Herpes simplex virus 1 transmission through corneal transplantation.

Genetic characterisation of herpes simplex virus type 1 (HSV-1) DNA isolated from a donor cornea before and after corneal transplantation demonstrated the transmission of HSV-1 through transplantation. This study is the first to provide conclusive evidence for the transmission of HSV-1 by penetrating keratoplasty with subsequent reactivation of donor-derived HSV-1 in the transplanted cornea.

Herpes simplex virus type 1 (HSV-1)--induced retinitis following herpes simplex encephalitis: indications for brain-to-eye transmission of HSV-1.

Herpes simplex encephalitis is a severe neurological disease with high mortality and morbidity rates. Reactivated herpes simplex virus type 1 (HSV-1) can cause relapses and might even spread to the retina, where it can induce a potentially blinding eye disease, known as acute retinal necrosis. In the present study, the HSV-1 strains in the brain and eye of 2 patients with acute retinal necrosis following an episode of herpes simplex encephalitis were genotyped. The HSV-1 strains in both the brain and eye were identical in each patient, but they differed interindividually. The data suggest brain-to-eye transmission of HSV-1 in these patients.

Herpes simplex virus type 1 (HSV-1)--induced retinitis following herpes simplex encephalitis: indications for brain-to-eye transmission of HSV-1.

Herpes simplex encephalitis is a severe neurological disease with high mortality and morbidity rates. Reactivated herpes simplex virus type 1 (HSV-1) can cause relapses and might even spread to the retina, where it can induce a potentially blinding eye disease, known as acute retinal necrosis. In the present study, the HSV-1 strains in the brain and eye of 2 patients with acute retinal necrosis following an episode of herpes simplex encephalitis were genotyped. The HSV-1 strains in both the brain and eye were identical in each patient, but they differed interindividually. The data suggest brain-to-eye transmission of HSV-1 in these patients.

Intraocular T cells of patients with herpes simplex virus (HSV)-induced acute retinal necrosis recognize HSV tegument proteins VP11/12 and VP13/14.

It has previously been shown that T cells specific for the triggering virus infiltrate the eye of patients with herpes simplex virus type 1 (HSV-1)-induced acute retinal necrosis (ARN). The T cells were mainly directed against 0.67-0.73 HSV-1 map region encoded antigens. The fine specificities of genetically different T cell clones (TCC), obtained from affected eyes of 3 patients with HSV-induced ARN and reactive toward this genomic region of HSV-1, were analyzed with recombinant HSV viruses and synthetic peptides. For 1 patient, the HSV-1 UL46 gene encoded tegument protein VP11/12 was identified as the target antigen. Two separate CD4(+) T cell epitopes were defined in VP11/12. TCC from the other 2 patients recognized the HSV-1 UL47 gene encoded tegument protein VP13/14. Two separate CD4(+) VP13/14 T cell epitopes were identified in these patients. Analysis of the data indicates that HSV-1 VP11/12 and VP13/14 are major target antigens for T cells obtained from vitreous fluid samples of the HSV-induced ARN patients studied.

Herpes simplex virus-specific T cells infiltrate the cornea of patients with herpetic stromal keratitis: no evidence for autoreactive T cells.

PURPOSE: Herpetic stromal keratitis (HSK) is a T-cell-mediated inflammatory disease initiated by a herpes simplex virus (HSV) infection of the cornea. Recently, studies in the HSK mouse model have shown that the immunopathogenic T cells are directed against the HSV protein UL6 cross-reacting with an unknown corneal autoantigen. Whether this type of autoimmunity plays a role in human HSK was analyzed. METHODS: T-cell lines (TCLs) were generated from corneal buttons of 12 patients with different clinical stages of HSV-induced necrotizing stromal keratitis (n = 9) or immune stromal keratitis (n = 3). The initiating virus was identified by polymerase chain reaction and immunohistology performed on the corneal buttons. Peripheral blood mononuclear cells (PBMCs) were isolated, and B cell lines (BLCLs) were generated by transformation with Epstein-Barr virus. Proliferative responses of these intracorneal TCLs were determined by culturing T cells with autologous BLCLs infected with HSV-1, HSV-2, wild-type vaccinia virus (VV-WT), or VV expressing HSV-1 UL6 (rVV-UL6). Alternatively, T cells were incubated with PBMCs pulsed with human cornea protein extract. RESULTS: Irrespective of clinical diagnosis or treatment, T cells were recovered from the corneal buttons of all the 12 HSK patients. The intracorneal TCLs of 9 of the 12 HSK patients showed HSV-specific T-cell reactivity. In none of the TCLs, T-cell reactivity against HSV-1 UL6 or human corneal antigens was detected. CONCLUSIONS: These data suggest that the potentially immunopathogenic intracorneal T-cell response in HSK patients is directed to the initiating virus and not to a human corneal autoantigen or HSV-1 UL6.

Amplification of reiterated sequences of herpes simplex virus type 1 (HSV-1) genome to discriminate between clinical HSV-1 isolates.

Herpes simplex virus type 1 (HSV-1)-related disease ranges from a localized, self-limiting illness to fatal disease in immunocompromised individuals. The corneal disease herpetic keratitis may develop after reactivation of a latent virus or reinfection with an exogenous herpesvirus. Molecular analysis of the virus involved may allow distinction between these two options. The HSV-1 genome contains several hypervariable regions that vary in numbers of reiterating regions (reiterations I to VIII [ReI to ReVIII]) between individual strains. Twenty-four HSV-1 clones, derived by subcloning of HSV-1 (strain F) twice in limiting dilutions, were tested in a PCR-based assay to analyze the stabilities of ReI, ReIII, ReIV, and ReVII. ReI and ReIII proved to vary in size upon subcloning, whereas ReIV and ReVII were stable. Subsequently, 37 unrelated isolates and 10 sequential isolates from five patients, all with HSV-1-induced keratitis, were genotyped for ReIV and ReVII. Of the 37 unrelated samples, 34 (92%) could be discriminated, while the genotypes of the viruses in sequential samples were identical for each individual. Conclusively, the data show that the approach presented allows the rapid and accurate discrimination of HSV-1 strains in studies that address the transmission and pathogenesis of HSV-1 infections.

Polymorphism within the tumor necrosis factor alpha (TNF) promoter region in patients with ankylosing spondylitis.

In addition to HLA-B27, other genetic factors are thought to be involved in the pathogenesis of ankylosing spondylitis (AS). Because of the location of the TNF gene in the vicinity of the HLA-B locus, and the prominent role in inflammation of its product, we investigated the association between AS and two G to A transition polymorphisms located at position -238 and -376 in the promoter region of the TNF gene. The distribution of the TNF alleles was determined in 86 HLA-B27+ AS patients and 163 healthy controls. From the 86 AS patients, 33 suffered from acute anterior uveitis (AAU). No significant difference for the TNF-376 polymorphism in AS and healthy controls was observed. The frequency of the TNF-238A allele in HLA-B27+ AS patients was significantly decreased compared to random controls (p = 0.021). However, the frequency of the TNF-238A allele in HLA-B27+ AS patients was not significantly different from that observed in HLA-B27+ healthy individuals (p = 0.6). Assessment of association showed that the TNF-238G allele is in linkage disequilibrium with the HLA-B27 allele (delta = 0.053; P = 0.008). Therefore, we conclude that the association between TNF-238G and AS is secondary to the HLA-B27 gene and that TNF-238 and-TNF-376 alleles are not likely to be involved in the susceptibility to AS.