Frequency of HIV type 1 dual infection and HIV diversity: analysis of low- and high-risk populations in Mbeya Region, Tanzania.

HIV-1 diversity, frequency of recombinants, and dual infection were determined in two populations with different HIV risk behavior. A high-risk cohort of 600 female bar workers and a normal-risk population of 1,108 antenatal clinic attendees and blood donors were recruited. Behavioral data were assessed and blood for HIV- 1 diagnosis and genotyping was sampled. HIV-1 subtypes were defined through the multiregion hybridization assay (MHA(acd)). HIV-1 prevalence differed significantly among the two populations. The prevalence was 67.8% in the population of bar workers and 17% in the normal-risk population (antenatal care attendees and blood donors). Within the normal-risk population the HIV-1 prevalence was lowest in the group of volunteer blood donors. The frequency of HIV-1 infection in women was 1.7 times higher than in men. The overall subtype distribution was A (8.5%), C (40.8%), D (3.8%), AC (25.4%), AD (5.4%), CD (8.8%), and ACD (7.3%). In the high-risk population there was a higher percentage of HIV-1 recombinant strains (54% vs. 40%, p < 0.05) and a higher frequency of dual infections (19% vs. 9%, p < 0.02) compared to the normal-risk population. High-risk populations may play an important role in the evolution of HIV, as they can provide an opportunity for the virus to coinfect, recombine, and adapt to the host-specific genetic background.

Myelin basic protein-reactive autoantibodies in the serum and cerebrospinal fluid of multiple sclerosis patients are characterized by low-affinity interactions.

The presence of autoantibodies to the immunodominant antigen, myelin basic protein (MBP), in the serum and cerebrospinal fluid (CSF) of patients with multiple sclerosis (MS) has been poorly characterized. Many studies report detectable levels of autoantibodies to myelin basic protein though other studies, using similar techniques, report their absence. We compared a solution-phase assay that has detected clinically relevant autoantibodies in diabetes and other autoimmune diseases to solid phase assays similar to those used in previous reports. The solution-phase assay consistently measured autoantibodies to MBP in serum from human subjects with Semple rabies vaccine (SRV)-induced demyelinating disease and from MBP-immunized animals. A solid phase assay detected MBP autoantibodies in the serum of a fraction of patients with MS. Autoantibodies capable of binding to MBP in the solution-phase were not detected in the CSF or serum of patients with MS. Additional solution-phase measurements revealed that anti-MBP antibodies from individuals with SRV-induced demyelinating disease demonstrated a binding affinity profile consistent with that of polyclonal antibodies with a range of affinities from low to high. In contrast, antibodies to MBP in the serum of MS patients detected by ELISA did not bind soluble MBP in the same assay. These results indicate that the humoral response in patients with MS does not include moderate- or high-affinity autoantibodies to MBP.

Maintaining low HIV type 1 env genetic diversity among injection drug users infected with a B/C recombinant and CRF01_AE HIV type 1 in southern China.

HIV-1 outbreaks in Guangxi Province, southern China were initiated from two separate border cities in 1996 and 1997. Drug users in Pingxiang City, which borders Vietnam, were infected with CRF01_AE HIV-1, and drug users in Baise City, which borders Yunan Province, were infected with a novel B/C recombinant HIV-1. Since 1997, HIV-1 has been rapidly spreading in Guangxi, including its capital city Nanning. Survey data indicated that HIV-1 prevalence among IDUs in new outbreak regions increased 8 to 42% within 1 year. The B/C recombinants obtained from five separate regions in Guangxi, which span a 4-year time frame, were remarkable for their low intersubject env V3 diversity, less than 0.2%. Similarly, the CRF01_AE from IDUs over a 3-year time frame had low intersubject env V3 diversity of less than 1.6%. Different patterns of sequence variations in the V3 and V4 regions were observed for the B/C recombinant and the CRF01_AE HIV1. The rapid spreading of homogeneous HIV-1 strains in Guangxi may have important implications for HIV transmission as well as vaccine development and evaluation.

Neuropsychiatric manifestations in Thai patients with systemic lupus erythematosus.

Neuropsychiatric (NP) manifestations in patients with systemic lupus erythematosus (SLE) [NPSLE] and prognostic factors were studied in 91 patients. There were 98 NP episodes, of which 78 (79.6%) occurred within the first year of the disease. Twenty-six patients (6.7%) had NPSLE as an initial presentation of the disease. There were seizures in 53 episodes (54.1%), psychosis in 13 (13.3%), acute confusion state in 11 (11.2%), abnormal consciousness in 6 (6.1%), transverse myelitis in 6 (6.1%), peripheral neuropathy in 5 (5.1%), cerebral infarction in 2 (2.0%) and aseptic meningitis in 2 (2.0%). Most forms of NPSLE responded well to high dose corticosteroids. Anti-convulsant therapy could be discontinued within a median duration of 3 months after the SLE activity was under control, and without significant recurrence of seizures. The 5-year and 10-year survival rates of patients with NPSLE were 75.9% and 50.6%, respectively. Patients with NPSLE had significantly more cutaneous vasculitis and less arthritis than those without.

Hemagglutinin protein is a primary target of the measles virus-specific HLA-A2-restricted CD8+ T cell response during measles and after vaccination.

To characterize the measles virus (MV)-specific T cell responses important for evaluation of measles vaccines, human leukocyte antigen (HLA)-A2-positive and -negative adults immunized with measles-mumps-rubella vaccine were studied. Both groups developed increases in antibody and in interferon (IFN)- gamma -producing cells in response to pooled hemagglutinin (H) and fusion peptides. HLA-A2-binding peptides were predicted for all MV-encoded proteins and confirmed by T2 cell stabilization. Twenty-nine peptides were tested, and 19 (6 from H) stimulated increased IFN- gamma secretion in a majority of vaccinees. Peptide-loaded HLA-A2 tetramers or immunoglobulin dimers documented MV-specific CD8+ T cell responses after vaccination and during measles and confirmed new A2 epitopes in H (250-259 and 516-525 aa) and matrix (M; 50-58 aa) protein and previously described epitopes in H (30-38 aa), M (211-219 aa), and nonstructural protein C (84-92 aa). No single peptide dominated the response. We conclude that H is an important stimulus for CD8+ T cell as well as for antibody responses in HLA-A2-positive individuals.

Neurological adverse events associated with vaccination.

Public tolerance to adverse reactions is minimal. Several reporting systems have been established to monitor adverse events following immunization. The present review summarizes data on neurologic complications following vaccination, and provides evidence that indicates whether they were directly associated with the vaccines. These complications include autism (measles vaccine), multiple sclerosis (hepatitis B vaccine), meningoencephalitis (Japanese encephalitis vaccine), Guillain-Barré syndrome and giant cell arteritis (influenza vaccine), and reactions after exposure to animal rabies vaccine. Seizures and hypotonic/hyporesponsive episodes following pertussis vaccination and potential risks associated with varicella vaccination, as well as vaccine-associated paralytic poliomyelitis following oral poliovirus vaccination, are also described. In addition, claims that complications are caused by adjuvants, preservatives and contaminants [i.e. macrophagic myofasciitis (aluminium), neurotoxicity (thimerosal), and new variant Creutzfeldt-Jakob disease (bovine-derived materials)] are discussed.