Tumour necrosis factor (TNF) inhibitor therapy in Susac's syndrome.

Susac's syndrome is the clinical triad of encephalopathy, branch retinal artery occlusions and sensorineural hearing loss (Susac 1994) [1]. It occurs predominantly in young females and is believed to be an immune-mediated endotheliopathy of small vessels of the brain, retina and cochlea (Neumayer et al. 2009) [2]. Early, aggressive, and sustained immunosuppressive therapy has been recommended for Susac's syndrome and anecdotal evidence has suggested a therapeutic role for monoclonal antibodies (Rennebohm et al. 2008, Lee and Amezcua 2009) [3,4]. We report a case of Susac's syndrome in which the patient improved immediately after tumour necrosis factor (TNF) inhibition with the monoclonal antibody, infliximab.

The uptake of HIV post-exposure prophylaxis within a sexual assault setting in Sydney, Australia.

Our aim was to compare the assault characteristics of victims presenting to a sexual assault service who were prescribed HIV post-exposure prophylaxis (HIV PEP) with those not prescribed HIV PEP. A retrospective review was carried out of the medical records of victims who were seen over a 12-month period in 1999/2000.HIV PEP may have been potentially appropriate for 117 victims, of whom nine (7.7%) were prescribed PEP (eight women, one man). There was a trend for prescription of PEP to depend on the type of assault, with those suffering anal penetration most likely to be prescribed PEP, followed by those with vaginal, and then oral penetration (P = 0.08). Those who gave a history of oral or vaginal mucosal contact with ejaculate were more likely to receive PEP compared with those in whom ejaculation occurred at a non-mucosal site (P = 0.03). Most prescribed PEP regimens involved three antiretroviral drugs. In this study, HIV PEP, when prescribed, was in accord with existing guidelines. Future studies should aim to better document HIV seroconversions in victims of sexual assault and HIV seroprevalence in assailants.

Clinical features and predictors of survival of AIDS-related non-Hodgkin's lymphoma in a population-based case series in Sydney, Australia.

OBJECTIVES: To analyse clinical features and predictors of survival for AIDS-related non-Hodgkin's lymphoma (NHL) in the era of highly active antiretroviral therapy (HAART), compared to earlier in the HIV epidemic. METHODS: All AIDS-NHL cases diagnosed at three inner Sydney hospitals caring for people with AIDS during 1985-2001 were identified through medical record searches. Demographic, clinical, immunological and histopathological information was recorded. Year of NHL diagnosis was grouped into three periods, corresponding to whether monotherapy (1985-1991), dual therapy (1992-1995) or HAART (1996-2001) was the main treatment for HIV infection. Statistical comparisons were made between the pre-HAART and post-HAART eras. RESULTS: Three hundred cases of AIDS-NHL were identified. Divergent trends were identified for systemic and primary central nervous system (CNS) NHL. For systemic NHL, the CD4 count at NHL diagnosis increased markedly to 208 cells/microL in the post-HAART era (P=0.014) and there was a trend towards presentation as the first AIDS-defining illness (69%, P=0.053), and as earlier stage NHL disease (42%, P=0.048). Median survival time increased from 4.2 months in 1985-1991 to 19 months in the post-HAART era (P<0.001). In a multivariate model, predictors of poor survival from systemic NHL included: NHL diagnosis after another AIDS-defining illness (P<0.001), stage 4 NHL (P<0.001), presentation at extra lymphatic sites (P=0.001), and nonreceipt of chemotherapy (P=0.002). After adjusting for the factors, those diagnosed in the era of HAART had a significant 56% reduction in rate of death (P<0.001). In contrast, for CNS NHL, clinical features were little changed and survival did not improve in the era of HAART. CONCLUSIONS: Systemic NHL is presenting earlier in the course of HIV disease, and at a less advanced NHL stage. There has been a marked improvement in survival in the era of HAART even after adjustment for other prognostic variables. In contrast, primary CNS NHL remains a disease which presents late in the course of HIV infection and is associated with a very poor prognosis.

B-cell stimulation and prolonged immune deficiency are risk factors for non-Hodgkin's lymphoma in people with AIDS.

OBJECTIVES: To identify risk factors for non-Hodgkin's lymphoma (NHL) in people with HIV infection. DESIGN AND SETTING: Case-control study in Sydney, Australia. PARTICIPANTS AND METHODS: Two hundred and nineteen patients with AIDS-related NHL were compared with 219 HIV-infected controls without NHL, matched for CD4 positive cell count and date of specimen collection. Data on demographic, infectious, treatment-related and immunological factors were abstracted by medical record review. The association between demographic factors, sexually transmissible diseases, HIV-related opportunistic infections, anti-viral therapy, duration of immune deficiency and indices of immune stimulation and risk of NHL were derived for these groups. RESULTS: In a multivariate model, there were two independent groups of predictors of NHL risk. The first was duration of immunodeficiency, as measured by longer time since seroconversion (P for trend 0.008), and lower CD4 positive cell count 1 year prior to the time of NHL diagnosis (P for trend 0.009). The second predictor was B-cell stimulation, as indicated by higher serum globulin (a surrogate marker for serum immunoglobulin, P for trend 0.044) and HIV p24 antigenaemia [odds ratio (OR) for p24 positivity, 1.82; 95% confidence interval (CI), 1.15-2.88]. Indices of B-cell stimulation preceded the diagnosis of NHL by several years. Factors not related to NHL risk included clinical indices of Epstein-Barr virus infection and receipt of individual nucleoside analogue antiretroviral agents. Combination therapy with these agents was associated with a non-significant reduction in NHL risk (OR, 0.68; 95% CI, 0.39-1.18). CONCLUSIONS: Markers of long-standing immune deficiency and B-cell stimulation were associated with an increased risk of developing NHL. Unless the strongest risk factor for NHL, immune deficiency, can be reversed, NHL is likely to become proportionately more important as a cause of morbidity and mortality in people with HIV infection.

Immunologic and virologic status after 14 to 18 years of infection with an attenuated strain of HIV-1. A report from the Sydney Blood Bank Cohort.

BACKGROUND AND METHODS: The Sydney Blood Bank Cohort consists of a blood donor and eight transfusion recipients who were infected before 1985 with a strain of human immunodeficiency virus type 1 (HIV-1) with a deletion in the region in which the nef gene and the long terminal repeat overlap. Two recipients have died since 1994, at 77 and 83 years of age, of causes unrelated to HIV infection; one other recipient, who had systemic lupus erythematosus, died in 1987 at 22 years of age of causes possibly related to HIV. We present longitudinal immunologic and virologic data on the six surviving members and one deceased member of this cohort through September 30, 1998. RESULTS: The five surviving recipients remain asymptomatic 14 to 18 years after HIV-1 infection without any antiretroviral therapy; however, the donor commenced therapy in February 1999. In three recipients plasma concentrations of HIV-1 RNA are undetectable (<200 copies per milliliter), and in two of these three the CD4 lymphocyte counts have declined by 9 and 30 cells per cubic millimeter per year (P=0.3 and P=0.5, respectively). The donor and two other recipients have median plasma concentrations of HIV-1 RNA of 645 to 2850 copies per milliliter; the concentration has increased in the donor (P<0.001). The CD4 lymphocyte counts in these three cohort members have declined by 16 to 73 cells per cubic millimeter per year (P<0.001). In the recipient who died after 12 years of infection, the median plasma concentration of HIV-1 RNA was 1400 copies per milliliter, with a decline in CD4 lymphocyte counts of 17 cells per cubic millimeter per year (P=0.2). CONCLUSIONS: After prolonged infection with this attenuated strain of HIV-1, there is evidence of immunologic damage in three of the four subjects with detectable plasma HIV-1 RNA. The CD4 lymphocyte counts appear to be stable in the three subjects in whom plasma HIV-1 RNA remains undetectable.

Managing HIV. Part 6: People living with HIV. 6.4 Medically acquired HIV infection.

Often an underlying disorder (such as haemophilia) creates special management issues for people with medically acquired HIV. Although the risk of infection through donated biological materials is now slight, an unknown number of undiagnosed cases remain in the community.

A controlled study of anxiety and morbid cognitions at initial screening for human immunodeficiency virus (HIV) in a cohort of people with haemophilia.

AIM: This study examines the relationship between anxiety, psychological state and Human Immunodeficiency Virus (HIV) stages as defined by the Centers for Disease Control at the time of initial screening for HIV in a cohort of people with haemophilia who were at risk of prior exposure to HIV transmission from blood products. METHOD: Psychological scores, immunological measures, and clinical data from case notes for 116 potentially HIV exposed people with haemophilia attending initial screening for HIV infection in 1984-1985, were used to examine the relationship between psychological variables, clinical state and their clinical classification under the Centres for Disease Control categorization. Psychometric test results were obtained for 63 HIV seronegative patients and 53 HIV seropositive patients. Planned comparisons, multiple and logistic regressions, were used to explain observed differences between seronegative and seropositive subjects. The potential confounders of sex, age, severity of haemophilia, haemophilia type and blood product usage were controlled. RESULTS: The major finding of this study was that higher levels of State Anxiety at the time of initial screening for HIV, were observed in those patients who lacked recognized symptoms of HIV infection and were seropositive, compared with seronegative subjects. The State Anxiety scores were predicted by HIV infection or alternatively CD4+ T-cell levels. CONCLUSION: The findings of this study suggest that HIV infection can produce psychological effects prior to any physical symptoms of infection being apparent.

The limited (needle biopsy) autopsy and the acquired immunodeficiency syndrome.

It is often uncertain whether deaths that occur during active treatment for complications of AIDS result from diagnostic or therapeutic failure. Accurate diagnosis of infections is particularly important, and has relevance not only for the patient but also to partners, relatives, hospital staff and other patients. In the absence of adequate physical facilities and in view of the lack of success in obtaining formal autopsies in patients dying with AIDS, a limited autopsy protocol was devised for routine application at our hospital, beginning in 1989. The major aim of this protocol was to enable the safe collection of diagnostic material from patients who died despite active therapy, to ascertain unrecognized conditions and confirm existing diagnoses. We present findings from the first 16 limited autopsies which resulted in 12 additional diagnoses and a revision of the principal cause of death in 7 cases.

Other laboratory clues to the diagnosis of HIV infection. A key summary.

The variety of problems induced by HIV means that any one of a wide range of investigations may uncover the first clue to unsuspected infection. Some of the more common abnormalities reported on by pathologists and radiologists which should raise the thought of underlying HIV infection are listed in this summary.

The low risk of hepatitis C virus transmission among sexual partners of hepatitis C-infected hemophilic males: an international, multicenter study.

To study the transmission rate of hepatitis C virus (HCV) in the female sexual partners of antibody-positive hemophilic males, 106 partners from three hemophilia centers located in Europe, America, and Australia were tested for HCV seropositivity using a first-generation enzyme-linked immunosorbent assay (ELISA-1) and, subsequently, a second-generation ELISA (ELISA-2) and a supplemental recombinant immunoblot assay. Additionally, the cohort was tested for the presence of antibody to the human immunodeficiency virus type-1 and hepatitis B virus markers. No female partner was HCV antibody-positive using the ELISA-1 test, whereas five were seropositive by the ELISA-2 test. Three of these five female partners were seropositive on the supplemental test, the remaining two having indeterminate results, for an overall prevalence of 2.7%. Thus, even with the use of sensitive testing, the prevalence of HCV infection remains low in this cohort, showing that the efficiency of heterosexual transmission of HCV is poor.

Progression of HIV-related disease is associated with HLA DQ and DR alleles defined by restriction fragment length polymorphisms.

A cohort of 139 hemophiliacs was typed for HLA D region genes by means of restriction fragment length polymorphisms (RFLPs) detected by HLA DQ and DR gene probes. Disease progression was studied in the 65 HIV antibody-positive patients, who were infected by contaminated clotting factor before 1985. Strong associations were found between disease progression in HIV-infected patients and allelic DNA fragments revealed by a DQ alpha cDNA probe. A 5.5 kb fragment was reduced in frequency and a 4.6 kb fragment increased in frequency (p less than 0.005) in the faster progressing group, as measured both by development of CDC Category IV clinical symptoms and CD4 number less than 200 x 10(6)/l. These results correlate with DR types deduced from the RFLP patterns revealed by DR beta and DQ alpha gene probes. A decrease in DR4 and an increase in both DR5 and the DR3 subtype found in the A1 B8 DR3 haplotype were associated with disease progression (p less than 0.05).

Sequence and immunogenicity of the 70-kDa heat shock protein of Mycobacterium leprae.

The gene encoding the Mycobacterium leprae 70-kDa heat shock protein has been isolated from a cosmid library using a fragment of the clone JKL2. Southern blot analysis of a positive clone identified a 4.4-kb fragment containing the entire coding region of the gene plus 2.4 kb upstream. Sequencing revealed the gene to encode a 621-amino acid protein, bearing 56% identity with the Escherichia coli dnaK gene product and 47% and 46% identity with the human and Caenorhabditis elegans hsp70, respectively. Comparison with the C-terminal 203 amino acids of the Mycobacterium tuberculosis 71-kDa Ag yielded 70% identity. Recombinant M. leprae p70 was produced in E. coli as a fusion protein (rp70f) with a portion of the schistosomal glutathione-S-transferase, using the expression vector, pGEX-2T. Cleavage with thrombin resulted in the release of a 70.0-kDa protein (rp70c) from the glutathione-S-transferase. Examination of the proteins by immunoblotting demonstrated that anti-M. leprae mAb, L7, and sera from lepromatous leprosy patients bound to both the cleaved and fusion proteins. We compared the T cell reactivity of the M. leprae recombinant proteins with that of mAb affinity-purified bacille Calmette-Guerin (BCG) 70-kDa Ag using proliferation assays. PBMC of BCG vaccinees responded to both M. leprae cleaved and fusion p70, though more subjects responded to the rp70c (18 of 20) than to rp70f (13 of 20). Responses were generally higher to rp70c than to rp70f, however all responses to the M. leprae recombinant proteins were lower than to mAb affinity-purified BCG p70. Thus, the M. leprae 70-kDa heat shock protein elicits T and B cell responses in subjects exposed to mycobacteria, despite its homology with the human hsp70.

Anti-Tac-H, a humanized antibody to the interleukin 2 receptor, prolongs primate cardiac allograft survival.

High-affinity interleukin 2 receptors (IL-2Rs) are expressed by T cells activated in response to foreign histocompatibility antigens but not by normal resting T cells. To exploit this difference in IL-2R expression, anti-Tac-M, a murine monoclonal antibody specific for the IL-2R alpha chain, was used to inhibit organ allograft rejection. However, the use of murine anti-Tac as an immunosuppressive agent was limited by neutralization by human anti-murine antibodies and by weak recruitment of effector functions. To circumvent these difficulties, a humanized antibody to the IL-2R, anti-Tac-H, was prepared. This molecule is human with the exception of the hypervariable segments, which are retained from the mouse. In vivo survival of anti-Tac-H is 2.5-fold longer than simultaneously administered anti-Tac-M (terminal t1/2, 103 hr vs. 38 hr). In addition, anti-Tac-H is less immunogenic than anti-Tac-M when administered to cynomolgus monkeys undergoing heterotopic cardiac allografting. Specifically, all monkeys treated with anti-Tac-M developed measurable anti-anti-Tac-M levels by day 15 (mean onset, 11 days). In contrast, none of the animals receiving anti-Tac-H produced measurable antibodies to this monoclonal antibody before day 33. Finally, there was a prolongation of graft survival in the cynomolgus heterotopic cardiac allograft model in animals receiving anti-Tac. In animals that received anti-Tac-M, the allograft survival was prolonged compared to that of the control group (mean survival, 14 +/- 1.98 days compared to 9.2 +/- 0.48 days; P less than 0.025). Graft survival was further prolonged by anti-Tac-H with a mean survival of 20.0 +/- 0.55 days (compared to controls, P less than 0.001; compared to anti-Tac-M, P less than 0.02). There was no toxicity attributable to the administration of either form of anti-Tac. Thus, anti-Tac-H significantly prolonged allograft survival in primates, without toxic side effects, and may be of value as an adjunct to standard immunosuppressive therapy in humans.

IL2-PE664Glu, a new chimeric protein cytotoxic to human-activated T lymphocytes.

To produce a molecule that will kill activated T cells as well as lymphomas and leukemias expressing interleukin 2 (IL2) receptors, we have created a recombinant chimeric protein in which IL2 is attached in peptide linkage to a truncated mutant form of Pseudomonas exotoxin (PE) (Lorberboum-Galski, H., FitzGerald, D.J.P., Chandhary, V.K., Adhya, S., and Pastan, I. (1988) Proc. Natl. Acad. Sci. U.S.A. 85, 1922-1926). Although this molecule was very active on rodent cells, it had lower activity on some human cell types. A new chimeric protein termed IL2-PE664Glu has been constructed that is extremely toxic to both phytohemagglutinin blasts and mixed leukocyte reaction blasts prepared from monkey and human lymphocytes. The chimeric gene encoding this protein was constructed by fusing a cDNA clone for human interleukin 2 to the 5' end of a mutated cDNA encoding a full-length PE molecule. Four amino acids in domain I of PE were changed thus decreasing its nonspecific toxicity. IL2-PE664Glu is a much more active cytotoxic molecule for primate and human-activated T cells than IL2-PE40 which is a chimeric protein that was found to be an effective immunosuppressive agent in rodent models. Our results indicate that IL2-PE664Glu should be evaluated as an immunosuppressive agent for the treatment of human immune disorders in which activated T cells expressing the IL2 receptor are prominent.

T cell reactivity to the purified mycobacterial antigens p65 and p70 in leprosy patients and their household contacts.

T cell reactivity to the 70 and 65 kD (p70 and p65) protein antigens derived from Mycobacterium bovis BCG strain was studied by measuring the proliferative responses of peripheral blood mononuclear cells from members of an isolated Aboriginal community resident in the Torres Straits islands. In the nine index leprosy cases the pattern of responsiveness to the purified antigens paralleled that to whole sonicates from M. leprae and BCG. In the 40 contacts of the index cases, a high correlation was observed between the responses to p70 and p65 as well as to the crude sonicates. Significant T cell responses to the purified antigens, as well as the crude sonicates, were obtained with cells from the majority of contacts. Limiting dilution analysis of precursor frequencies in the contacts confirmed the immunogenicity of the purified antigens and excluded both a mitogenic component and the presence of suppressor cells in those moderate or low responders whose blood contained sufficient precursors to be tested. p70 appeared to be more potent in stimulating a proliferative response than p65 at equivalent protein concentrations. No correlation between responder status to either antigen and disease type was detected in families. These findings provide confirmation of the importance of p70 and p65 as major T cell immunogens in man and indicate that they are both potential candidates for inclusion in a bivalent vaccine for leprosy and tuberculosis.

IgM serum antibodies to phenolic glycolipid-I and clinical leprosy: two years' observation in a community with hyperendemic leprosy.

A village population with hyperendemic leprosy in Papua New Guinea was repeatedly examined for clinical leprosy and for serum IgM antibodies to phenolic glycolipid-I (APGL-I) over 2 years between 1984 and 1986. In 1984, serum APGL-I was elevated in 15% of the subjects without clinical leprosy, and the prevalence of seropositivity was not significantly different in subjects from households with or without leprosy. In 1986, the prevalence of elevated serum APGL-I in leprosy-free subjects had risen to 23%. The incidence of seroconversion from APGL-I negative to APGL-I positive was 9.5% per year (95/1000 person years) in 253 subjects tested in 1984 and 1986. During the same period, 27 of 40 (67%) leprosy-free subjects reverted from positive to negative. The positive seroconversion rate in the community was higher than the incidence of clinical leprosy (11.2/1000 person years) over the same period. However, elevated serum APGL-I was not associated with clinical disease and failed to predict the development of disease over 2 years. The significance of persistent seropositivity found in 14 (5%) leprosy-free subjects is uncertain.

Homology of the 70-kilodalton antigens from Mycobacterium leprae and Mycobacterium bovis with the Mycobacterium tuberculosis 71-kilodalton antigen and with the conserved heat shock protein 70 of eucaryotes.

Two lambda gt11 recombinant clones, JKL2 and JKL15, each containing an insert coding for part of the highly immunogenic 70-kilodalton (kDa) protein antigen, were isolated from a Mycobacterium leprae genomic library by immunoscreening with the monoclonal antibody L7. Clone JKL2 contained the largest insert, 2.3 kilobase pairs. Nonoverlapping fragments of this insert were used as probes and showed strong hybridization to a number of Mycobacterium tuberculosis-lambda gt11 recombinants producing proteins recognized by an anti-M. tuberculosis 71-kDa monoclonal antibody, IT11. One clone from a recombinant Mycobacterium bovis library was also characterized by using L7, and the insert from this clone, B5bt, hybridized strongly to the M. leprae probes as well. The nucleotide sequence of the 1,037-base-pair coding region of the JKL2 M. leprae clone which encodes the carboxy-terminal half of the 70-kDa protein had extensive homology with genes from a number of species. In all cases, these genes, including the recently described Ag63 and Ag361 of Plasmodium falciparum, were found to be members of the heat shock protein 70 (hsp 70) family of genes. At the amino acid level, homology was maximal between amino acids 83 through 107 and 159 through 184, which showed extreme conservation (92 and 85% identity) with Escherichia coli DnaK amino acids 386 through 409 and 460 through 485, respectively, and was 51% homologous over the entire coding region (amino acids 1 through 344 of JKL2). In contrast, amino acids 129 through 158 had maximal homology with the phylogenetically more distant Xenopus laevis hsp70. Homology declined substantially in the carboxy-terminal 34 amino acids. The predicted ATP-binding functional activity of the 70-kDa antigen from M. bovis was confirmed with affinity purification of the antigen by binding to ATP-agarose and elution with ATP. In view of the conservation of sequences between these mycobacterial antigens and mammalian endogenous cellular enzymes, further evaluation of these molecules in vivo may aid in understanding tolerance to self-antigens as well as provide potentially useful immunodiagnostic reagents.

Antigens of Mycobacterium leprae identified by immunoprecipitation with sera from leprosy and tuberculosis patients.

Mycobacterial antigens which react with human B lymphocytes were investigated by immunoprecipitation of radiolabelled sonicates of Mycobacterium leprae and M. bovis (BCG) with sera from patients with leprosy and tuberculosis in the presence of Staphylococcus aureus. SDS-PAGE analysis of the immunoprecipitates demonstrated that dense bands of Mr 12,000 (12K), 15K, 27K, 32-33K, 36K and 48K were the major antigens of M. leprae recognized by antibodies in lepromatous leprosy sera. Of these, only the 15-16K band reacted significantly with sera from patients with tuberculoid leprosy and tuberculosis. Other antigens including the T cell immunogens of Mr 18K and 70K reacted with some of the BL/LL sera tested. There were differences in the pattern of antigens precipitated from BCG sonicate by leprosy sera with the 65K antigen and a high molecular weight band (greater than 94K) being readily detected. These results differ in part to these obtained by probing immunoblots of M. leprae sonicate with leprosy sera. Factors contributing to these differences are discussed.