Cerebrospinal Fluid IgG Research Articles

Detection of IgG and IgM to West Nile virus. Development of an immunofluorescence assay.

West Nile virus (WNV) had its first recorded appearance in the western hemisphere in 1999 and has continued to spread across the United States, necessitating the development of serologic procedures to diagnose infection. We developed an immunofluorescence assay (IFA) protocol for the detection of WNV-specific IgG and IgM antibodies in serum and cerebrospinal fluid (CSF) specimens. We tested 82 serum and 16 CSF samples and compared the results with WNV IgG enzyme-linked immunosorbent assay (ELISA) and IgM antibody-capture (MAC) ELISA results. Agreement, clinical sensitivity, and clinical specificity for the IgG IFA were 92%, 100%, and 90%, respectively, and 98%, 96%, and 100% for the IgM IFA, respectively. Extensive arbovirus cross-reactions occurred in the IgG assays, but only minimal cross-reactions were observed in the IgM assays. The IFA protocol described herein is a cost-effective and sensitive alternative to ELISA and MAC-ELISA for the serologic diagnosis of WNV infection.

Detection of IgG and IgM to West Nile Virus

West Nile virus (WNV) had its first recorded appearance in the western hemisphere in 1999 and has continued to spread across the United States, necessitating the development of serologic procedures to diagnose infection. We developed an immunofluorescence assay (IFA) protocol for the detection of WNV-specific IgG and IgM antibodies in serum and cerebrospinal fluid (CSF) specimens. We tested 82 serum and 16 CSF samples and compared the results with WNV IgG enzyme-linked immunosorbent assay (ELISA) and IgM antibody-capture (MAC) ELISA results. Agreement, clinical sensitivity, and clinical specificity for the IgG IFA were 92%, 100%, and 90%, respectively, and 98%, 96%, and 100% for the IgM IFA, respectively. Extensive arbovirus cross-reactions occurred in the IgG assays, but only minimal cross-reactions were observed in the IgM assays. The IFA protocol described herein is a cost-effective and sensitive alternative to ELISA and MAC-ELISA for the serologic diagnosis of WNV infection.

Molecular heterogeneity, detected by two electrophoretic micro procedures, of IgG in human cerebrospinal fluid (CSF).

Semi-automated electrophoretic procedures in the PhastSystem (Amersham Pharmacia Biotech) with micro polyacrylamide gels (PAGs) and SDS-PAG gradients were modified to analyze IgG in human cerebrospinal fluid (CSF) and matched serum samples with respect to the molecular IgG structure L-H-H-L. Isoelectric focusing (IEF) with specific immunofixation detected discrete IgG bands in CSF standing out against a polyclonal and monoclonal background pattern in CSF and serum; they were denoted oligoclonal bands (IgG OBs) (OB assay positive) indicating IgG synthesis in the central nervous system (CNS) of patients with subacute and chronic processes of inflammatory CNS disorders; assay was negative with identical (mirror) bands in CSF and serum for other CNS processes. IgG OBs were specified as lambda (kappa) IgG subfractions, precipitated with the anti-light (L) chains lambda (kappa) and anti-heavy (H) chain fragments (Fd, Fc, C(H)2) as well as with anti-F(ab')(2), and as duplex IgGs with kappa and lambda OBs at the same pI. With SDS-PAG gradient electrophoresis and specific immunofixation more than six IgG fractions were detected and classed according to apparent molecular weights of a S-sulfonated human IgG standard; they were characterized with the monospecific antibodies against the L and H chain fragments as 25, 50, 75, 100, 125 and 150 kD fractions containing combinations of L and H chains as well as mixtures of both L and H chain fragments of varying dimensions. Generally, this molecular IgG heterogeneity could not be connected with the IgG OB heterogeneity revealed by IEF; but single OBs in the strongly alkaline pH region of PAG may correspond to H fragments with basic pI. Nevertheless, evidence for the existence of both free L chains and the free H chain were revealed as specific OBs with IEF and with the anti-L and anti-H antibodies in the 25 kD and 50 kD fractions, respectively, of CSF samples of six patients with diverse CNS diseases. Further experiments are needed to elicit the origin of the molecular IgG heterogeneity during the immune response of subacute and chronic inflammatory processes in human CNS.

Clinical and immunological risk factors for severe disease in Japanese encephalitis

Eighty-five paediatric patients in Thailand with acute Japanese encephalitis (JE) were studied in 1987–1999 to determine risk factors present at hospital admission which were associated with severe disease. On univariate analysis, the following factors on admission were significantly associated with the combined end-point of death or a severe neurological deficit: depressed level of consciousness, elevated concentration of cerebrospinal fluid (CSF) protein, low levels of serum and CSF IgG antibody against Japanese encephalitis virus (JEV), low level of serum IgM antibody against JEV, and a serological response consistent with primary flavivirus infection. On multivariate analysis, an initial serum anti-JEV IgM < 150 U and the absence of a prior flavivirus infection, presumably dengue, remained independent risk factors for death or a severe neurological deficit. The ability to mount an early and vigorous JEV-reactive antibody response is associated with a better outcome from acute JE. An anamnestic, anti-flavivirus, immune response induced by a prior dengue virus infection can be an important means of providing this protection.

Detection of Oligoclonal Immunoglobulins in Cerebrospinal Fluid by an Immunofixation-Peroxidase Method

The detection of intrathecal synthesis of immunoglobulins is used in the diagnosis of multiple sclerosis (MS). We tested the semiautomated immunofixation-peroxidase (IFPOD) technique, which uses high-resolution agarose gel electrophoresis (HRAGE) directly followed by immunofixation with a peroxidase-labeled anti-IgG antiserum to detect oligoclonal immunoglobulins in cerebrospinal fluid (CSF). We analyzed 230 consecutive matched serum/CSF pairs that arrived in the laboratory over a 6-month period with both IFPOD and our routine techniques, immunofixation electrophoresis (IFE) and HRAGE. For IFPOD, CSF samples were not concentrated before testing. Among the 230 samples were 12 clinically definite MS, 33 clinically probable, and 20 clinically possible MS samples. IFPOD and HRAGE + IFE each detected oligoclonal IgG in CSF in 10, 16, and 7 cases of these respective groups. For clinically definite MS, sensitivity and specificity (95% confidence intervals) were, respectively, 83% (51-97%) and 79% (73-84%). The IFPOD technique performs comparably to other analytical methods, without the requirement for sample concentration, and may represent an attractive alternative in testing for intrathecal immunoglobulin synthesis.

Patrones de síntesis intratecal de inmunoglobulinas en epidemia de meningoencefalitis por echovirus 9

Epidemics of meningoencephalitis due to echovirus 9 were commonly occurred when a children population become susceptible for the first time in front the virus. To present the intrathecal synthesis pattern of immunoglobulins of the epidemic that affected Cuba in 1999 and to probe the usefulness of reibergram and antibody index in the diagnostic and characterization of the outbreak. 23 pediatric patients suffering from viral meningoencephalitis due to echovirus 9 were studied in the income moment. Serum and cerebrospinal fluid IgA, IgM, IgG, albumin and glucose were quantified. Cerebrospinal fluid total protein content and lactate were quantified. Titles of antibodies against echo 9 and Coxsackie A9 and differential cell count were performed. A mean of 555 cells/10 6 L mainly lymphocytes were obtained. Glucose in cerebrospinal fluid was over 50%, serum glucose and lactate levels below 2.1 mmol/L. In the reibergram an absence of intrathecal synthesis was predominant (15/23), IgM synthesis (6/23) and IgM+IgA (2/23). Blood cerebrospinal fluid dysfunction was observed in 15 patients. The mean antibody index was 1,8 for echo 9 and 0,9 for Coxsackie A9. The intrathecal synthesis pattern of immunoglobulins was different from other enterovirus and from echovirus 9 in non epidemic situations before this epidemic, probably with alteration of viral genome.

Humoral immune response to mycobacterial heat shock protein (hsp)65 in the cerebrospinal fluid of neuro-Behçet patients.

Although systemic immune reactivity to 65-kD mycobacterial hsp65 (m-hsp65) has been shown previously in Behçet's disease (BD), local immune response was not investigated. We studied anti-m-hsp65 IgG, IgM and IgA antibodies in the serum and cerebrospinal fluid (CSF) of 25 BD patients with cerebral parenchymal involvement (p-NBD), seven BD patients with intracranial hypertension (ih-NBD), eight BD patients without central nervous system (CNS) involvement, 30 patients with multiple sclerosis (MS) and 24 patients with non-inflammatory CNS disorders (NIC). Significantly higher CSF IgG responses were detected in p-NBD patients (ELISA ratio 1.3 +/- 0.9) compared with NIC (0.7 +/- 0.4, P < 0.01). In p-NBD patients' IgG, IgM or IgA CSF anti-m-hsp65 positivity rate was 48% (12/25); this was significantly higher when compared with MS (3/30; P < 0.03) and NIC (3/24; P < 0.01). CSF anti-m-hsp65 IgG ratios correlated with the duration of BD (r = 0.4, P < 0.04) but not with the duration of neurological involvement. Serum IgM and IgA responses were elevated in ih-NBD, suggesting a different type of involvement than p-NBD. These results implicate an increased local humoral response to m-hsp65 in the CSF of p-NBD patients, which might be related to the pathogenesis of neurological involvement.

Canine distemper infections, with special reference to South Africa, with a review of the literature.

Canine distemper virus is a member of the genus Morbillivirus of the family Paramyxoviridae that causes severe disease in dogs and a range of wild mammals. The clinical signs relate essentially to the respiratory, gastrointestinal and central nervous systems. In South Africa, infection with Ehrlichia canis and canine parvovirus may present similarly Many dogs will initially present with a wide range of central nervous system signs without any history of systemic disease. A recent South African study evaluating ante mortem diagnosis highlighted the importance of recognising clinical signs, cerebrospinal fluid IgG titres, serum IgM titres and immunocytochemistry of epithelial tissue. A 2-year retrospective evaluation of cerebrospinal fluid samples collected from dogs presented to the Onderstepoort Veterinary Academic Hospital indicates that distemper infection is common, and this disease should routinely be suspected in cases of diverse neurological disease in dogs. The South African dog population is specifically at high risk for the disease because of the large pool of unvaccinated, reproductively-active dogs that expose the wildlife resources of the country to risk of fatal disease. Outbreaks of disease in dogs continue to occur in developed and developing communities in both vaccinated and unvaccinated dogs worldwide, and have also been described in a wide range of free-ranging wildlife, including seals, dolphins and lions, and in endangered zoo animals. Modified live virus vaccines have contributed markedly to disease control in the dog population but have caused mortality in some wild carnivores. New recombinant vaccines are being developed that will be safe in wild animals. The pathogenesis of CNS demyelination has been compared to various important demyelinating diseases in humans and, amongst other things, relates to down-regulation of the oligodendrocyte gene coding for myelin synthesis and non-immunocyte CNS cell expression of type II major histocompatibility receptors. Early CNS lesions are characterised by demyelination and later lesions by perivascular round cell cuffing. Treatment is supportive.

Detection of IgG in cerebrospinal fluid for diagnosis of neurocysticercosis: evaluation of saline and SDS extracts from Taenia solium and Taenia crassiceps metacestodes by ELISA and immunoblot assay.

We compared saline (S) and sodium dodecyl sulphate (SDS) extracts from Taenia solium (homologous species - HO) and Taenia crassiceps (heterologous species - HE) metacestodes in order to detect IgG by ELISA and immunoblot assay (IBA) in cerebrospinal fluid (CSF) for the diagnosis of human neurocysticercosis (NC). CSF samples were obtained from 93 patients. Of these, 40 had NC, five had a diagnosis of probable NC, nine had central nervous system schistosomiasis or strongyloidiasis and 39 had other neurological alterations. Samples were analysed by ELISA and the results were compared with IBA in all samples with confirmed and probable NC diagnosis, in all samples with other central nervous system parasitic infection, and in 10 of those with another neurological alterations. ELISA sensitivity was 100%, 85%, 95% and 87.5% for the S-HO, S-HE, SDS-HO and SDS-HE extracts, respectively, and ELISA specificity was 100% for S-HO, S-HE, SDS-HO extracts and 97.9% for SDS-HE antigen. Immunodominant peptides detected by IBA were, by decreasing percentage of recognition: 64-68 and 45 kDa for S-HO; 108-114, 92-95, 64-68, 83 and 88 kDa for S-HE; 64-68, 108-114, 77 and 86 kDa for SDS-HO; and 108-114, 88 and 92-95 kDa for SDS-HE. Overall the homologous antigenic extracts showed higher sensitivity than the heterologous extracts in the diagnosis of NC in CSF samples. The heterologous extracts contained most of the immunodominant peptides presented in the homologous extracts, which are recognized by IgG antibodies in CSF samples.

Systemic disease and neuro-ophthalmology: annual update 2000 (Part I).

Multiple sclerosis (MS) is a common demyelinating disease of the central nervous system (1–86), with substantial long-term neurologic consequences (1,4,9,25,34, 52,54,55,57,60,63,65). After 10 years with MS, 50% of patients are unable to perform household and occupational responsibilities; after 15 to 20 years, 50% are unable to walk without assistance; after 25 years, 50% are unable to ambulate. The average annual cost of MS in the United States is greater than 6.8 billion dollars (1). There are three main subtypes of the disease: relapsing remitting (RR), secondary progressive (SP), and primary progressive (PP). This update reviews the current status of MS therapy (1–86). We have chosen to focus on the new and emerging immunomodulatory therapies for disease relapses and the treatments to prevent disease progression. We do not review the treatments for common MS-related sensory and motor symptoms, fatigue, or depression (35).

Neurocysticercosis: detection of IgG, IgA and IgE antibodies in cerebrospinal fluid, serum and saliva samples by ELISA with Taenia solium and Taenia crassiceps antigens.

We assayed samples of cerebrospinal fluid (CSF), serum and saliva from patients with neurocysticercoses, control group and individuals with other parasitoses, by ELISA with Taenia crassiceps vesicular fluid antigen (Tcra) and Taenia solium total antigen (Tso) for the detection of antibodies. The sensitivity for IgG-Tcra was 100% for CSF and serum, and 32.0% for saliva; and for IgG-Tso 100% for CSF, 80.0% for serum and 24.% for saliva. Specificity was 100% for CSF and 80.0% for serum with both antigens, and 100% for saliva with Tcra and 87.5% with Tso. The sensitivity and specificity for IgA-Tcra was, respectively, 40.0% and 100% for CSF, 36.0% and 97.1% for serum, and 4.0% and 90.0% for saliva. IgE detection showed 24.0% sensitivity and 97.1% specificity for serum, with no detection in CSF samples. The search for antibodies revealed the presence of IgG > IgA > IgE in CSF, serum and saliva samples, with IgG being present in all phases of the disease, while IgA/IgE were more frequent in the inactive form.

Ferritin, transferrin and iron concentrations in the cerebrospinal fluid of multiple sclerosis patients

The concentrations of ferritin, transferrin and iron were measured in the cerebrospinal fluid (CSF) of multiple sclerosis (MS) and control patients. Ferritin levels were significantly elevated in the CSF of chronic progressive active MS patients (4.71±0.54 ng/ml) compared to levels in normal individuals (3.07±0.17 ng/ml). MS patients with active or stable relapsing–remitting disease had ferritin levels that were comparable to those found in normal individuals. There were no significant differences in transferrin or iron levels in the CSF between MS and normal individuals. Both ferritin and transferrin levels were elevated in patients that had high CSF IgG values but not in patients with a high IgG index. Since ferritin binds iron, the increase of CSF ferritin levels in chronic progressive MS patients could be a defense mechanism to protect against iron induced oxidative injury. Ferritin levels could be a laboratory measure that helps to distinguish between chronic progressive and relapsing–remitting MS.

Reibergramas: elemento esencial en el análisis inmunológico del líquido cefalorraquídeo

The cerebrospinal fluid analysis is not displace on diagnosis of neurological disease in spite of the development of imaging techniques. Divulge the reibergrams as essential part of cerebrospinal fluid analysis. To perform a reibergram you have to quantify albumin, IgA, IgM and IgG in serum and cerebrospinal fluid. Then you have to calculate the quotients cerebrospinal fluid/serum and to plot the quotients in the reibergram. From the patterns you can have further information than single analyses. In contrast, the reibergram can yield the following information: about the intrathecal synthesis of immunoglobulins, CSF-blood barrier permeability and according to clinical data and symptoms can expect help in differential diagnosis by direct plausibilities or by suggesting the true diagnosis by pointing away from other diseases like opportunistic infections, neuro-tuberculosis and autoimmune inflammatory disease. It would be possible to detect an intrathecal tumour metastasis, monitoring efficacy of therapy and course of disease among others further knowledges. Reibergrams represent the best way to characterize blood-cerebrospinal fluid barrier function and intrathecal synthesis of immunoglobulins on neurological disorders.

Clonal expansion and somatic hypermutation of V(H) genes of B cells from cerebrospinal fluid in multiple sclerosis.

The cerebrospinal fluid (CSF) of multiple sclerosis (MS) patients is characterized by increased concentrations of immunoglobulin (Ig), which on electrophoretic analysis shows restricted heterogeneity (oligoclonal bands). CSF Ig is composed of both serum and intrathecally produced components. To examine the properties of intrathecal antibody-producing B cells, we analyzed Ig heavy-chain variable (V(H)) region genes of B cells recovered from the CSF of 12 MS patients and 15 patients with other neurological diseases (OND). Using a PCR technique, we could detect rearrangements of Ig V(H) genes in all samples. Sequence analysis of complementarity-determining region 3 (CDR3) of rearranged VDJ genes revealed expansion of a dominant clone or clones in 10 of the 12 MS patients. B cell clonal expansion was identified in 3 of 15 OND. The nucleotide sequences of V(H) genes from clonally expanded CSF B cells in MS patients demonstrated the preferential usage of the V(H) IV family. There were numerous somatic mutations, mainly in the CDRs, with a high replacement-to-silent ratio; the mutations were distributed in a way suggesting that these B cells had been positively selected through their antigen receptor. Our results demonstrate that in MS CSF, there is a high frequency of clonally expanded B cells that have properties of postgerminal center memory or antibody-forming lymphocytes.

Intrathecal IgM, IgA and IgG antibody response in tick-borne encephalitis. Long-term follow-up related to clinical course and outcome

Background: Tick-borne encephalitis (TBE) of western subtype causes long-term morbidity and is considered a health problem in Scandinavia, eastern and central parts of Europe and Russia. The pathophysiology is not fully elucidated. As TBE RNA is rarely demonstrable in cerebrospinal fluid (CSF) the kinetics of the CSF antibody response to the disease has attracted attention. Objectives: To investigate the intrathecal TBE-specific antibody response and to correlate its intensity and persistence to the clinical course. To compare indirect, commercially-based ELISA methods indexed against albumin ratio or IgG ratio with the capture ELISA method for the establishment of CSF response. Study design: The specific IgM, IgG and IgA antibody responses in serum and CSF were analysed in 69 Swedish patients included in a prospective study of TBE from the acute phase up to 11 – 13 months after onset. Results: Antibody response by all three classes was demonstrable in serum and CSF. All methods were useful, but capture technique was the most sensitive and results were easiest to interpret. Peak IgM activity was seen early during the disease and persisted after 6 weeks. Maximum IgG levels were encountered in late convalescent samples (median 6 weeks). Intrathecal antibody production was demonstrable in nearly all patients: in 41% days 0–6, in 97% days 7–19, in 98% days 21–61 and—at lower levels—in 84% of the patients after 1 year ( 50 52 of CSF-serum sampled in the interval 11–61 days). Day 9 after onset, patients with dominating encephalitic symptoms showed significantly lower intrathecal IgM activity. The persistence of serum and CSF antibodies did not correlate to severity of disease. Conclusions: Capture IgM and IgG assays were superior to indirect ELISA. Low early CSF IgM response correlated to encephalitic symptoms, otherwise the intensity and duration of intrathecal antibody response were of limited value for the prediction of clinical course and long-term outcome.

Soluble intercellular adhesion molecule-1 in serum and cerebrospinal fluid of clinically active relapsing-remitting multiple sclerosis: correlation with Gd-DTPA magnetic resonance imaging-enhancement and cerebrospinal fluid findings.

We measured soluble intercellular adhesion molecule-1 (sICAM-1) in the serum and cerebrospinal fluid (CSF) of 35 clinically active relapsing-remitting (RR) multiple sclerosis (MS) patients who underwent both lumbar puncture and gadopentetate dimeglumine (Gd-DTPA)-enhanced MRI within an interval of 1 week, and of 30 neurological controls of whom 17 had noninflammatory neurologic diseases (NIND), 8 bacterial meningitis (BM), and 5 AIDS dementia complex (ADC). Thirteen of the MS patients assumed corticosteroids at the time of the study. While sICAM-1 serum levels were highest in the BM group (p < 0.005), untreated MS patients showed levels higher (p < 0.05) than treated MS and NIND, but similar to ADC. Moreover, the untreated MS group had CSF/serum sICAM-1:CSF/serum albumin (sICAM-1 index) values higher than the treated group (p < 0.01), NIND (p < 0.005), and BM (p < 0.05); high sICAM-1 index was found also in ADC. Untreated MS patients with one or more Gd-DTPA-enhancing MRI lesions (Gd-positive) had higher mean values of CSF/serum albumin ratio (QAlbumin) and CSF mononuclear cells compared to patients without such lesions (Gd-negative). In the untreated Gd-negative patients, sICAM-1 serum levels were higher (p < 0.05) than those in Gd-positive patients. In the latter group, there were positive correlations between the number of CSF mononuclear cells and both IgG (p < 0.01) and sICAM-1 indices (p < 0.05), between QAlbumin and QsICAM-1 (p < 0.005) and between Qalbumin and the Expanded Disability Status Scale score (p = 0.05). There were no significant correlations in the Gd-negative group. These results suggest that sICAM-1 index can be a better marker of intrathecal sICAM-1 synthesis than CSF levels and provide additional insights, in vivo, into the blood-brain barrier mechanisms underlying MRI Gd-enhancement in clinically active RR MS.

Whipple's disease and the central nervous system a case report and a review of the literature

A 65-year-old man was suffering from recurrent manic psychosis accompanied by weight loss. He also had a history of pleural effusion, aspecific migratory non-deforming seronegative polyarthritis, sensorineural hearing loss and semicircular canal paresis. Whipple's disease (WD) had been diagnosed at the age of 63 years. On admission to hospital)he had weight loss, diarrhoea in combination with an organic, brain syndrome, hemiparesis and ophthalmoplegia, including internuclear ophthalmoplegia (INO). A clinical diagnosis of central nervous system (CNS) WD was made. MRI revealed a thalamus lesion that halved in size during sulfamethoxazole-trimethop:rim treatment. The organic brain syndrome and ophthalmoplegia diminished also, as did the cerebrospinal fluid (CSF) IgG level. A review of CNS WD is presented and implications for treatment are discussed.

Systemic high-dose recombinant-alpha-2a-interferon therapy modulates lymphokine production in multiple sclerosis

Chronic systemic high-dose recombinant alpha 2a-interferon (rIFNA) therapy reduces exacerbation rate and MRI signs of disease activity in relapsing/remitting multiple sclerosis (RR MS) patients. In order to clarify the possible mechanisms underlying the clinical efficacy of rIFNA in MS, several immunologic studies were performed as a part of a pilot clinical trial. Twenty RR MS patients were treated with 9 × 10 6 IU of rIFNA ( n = 12) or placebo ( n = 8) intramuscularly every other day for 6 months. Cytokine production by cultured lymphocytes, major histocompatibility complex class II (MHC-II) antigen expression on cultured macrophages, peripheral blood (PB) and cerebrospinal fluid (CSF) lymphocyte phenotype, and IgG and beta 2 microglobulin levels were studied before therapy, after 6 months of therapy, and 6 months after stopping therapy. rIFNA therapy was associated with reduction of interferon-gamma and tumor necrosis factor-alpha production by PB lymphocytes ( p < 0.04), and with slight, not significant, increase of transforming growth factor-beta 2 or interleukin (IL)-10 production. IL-4 was undetectable in the culture supernatants both before and after therapy. rIFNA therapy had no effect on macrophage MHC-II molecule expression. An increased percentage of CD8 +, CD8 + high CD11b + low, and CD3 − CD16 + CD56 + cells, and of CD4 + absolute cell number was observed in CSF after rIFNA therapy. After rIFNA administration, IgG level significantly increased both systemically ( p < 0.02) and intrathecally ( p < 0.001). Serum beta 2 microglobulin level increased ( p < 0.01), as well. Only 1 out of the 12 rIFNA treated patients developed neutralizing antibodies against rIFNA during therapy. Six months after stopping therapy all the immunologic changes returned to baseline. These data suggest that the beneficial effect of rIFNA therapy on MS disease activity is probably mediated by a downregulation of proinflammatory cytokine synthesis by PB lymphocytes rather than by macrophage MHC-II antigen expression. The immunologic effects of high-dose systemic rIFNA therapy are temporary and restricted to the period of drug administration.

Detection of both herpes simplex and varicella-zoster viruses in cerebrospinal fluid from patients with encephalitis.

Cerebrospinal fluid (CSF) samples from 46 patients with encephalitis were studied for the presence of herpes simplex virus (HSV) types 1 and 2 and/or varicella zoster virus (VZV)-specific DNA sequences by the polymerase chain reaction (PCR) assay. Patients were studied because of detection of intrathecal production of IgG antibody to HSV alone (10 patients, Group A) or to both HSV and VZV (11 patients, Group B) or because of the presence of specific anti-HSV IgG in CSF without evidence of intrathecal antibody production (25 patients, Group C). CSF samples taken between days 1 and 10 from onset of encephalitis were available from all patients, and follow-up samples (taken after 10 days from onset) were obtained from some of them. Positive PCR results were obtained in a total of 13 patients. Four patients (three from Group A and one from Group B) gave amplification of HSV type 1 DNA alone, two patients (both from Group B) showed amplification of VZV DNA alone, and seven patients (all from Group B) gave dual amplification of both HSV type 1 and VZV DNA sequences in CSF. All CSF samples from patients in Group C were negative by PCR. Ten patients with CSF samples positive by PCR lacked a prior history of herpetic cutaneous lesions. In seven patients, serum antibody tests (specific IgM detection and specific IgG avidity assays) identified both primary and recurrent infections. The results suggest that the dual presence of IgG antibody to both HSV and VZV in CSF from patients with encephalitis may reflect in some cases a dual infection of the central nervous system caused by both agents.

An immunovirological study of central nervous system involvement during HIV-1 infection of chimpanzees.

Chimpanzees infected with human immunodeficiency virus type 1 (HIV-1) are used to model acquired immunodeficiency syndrome (AIDS). Since the central nervous system (CNS) is involved in AIDS, we performed an immunovirological study in 18 chimpanzees inoculated up to 87 months prior to the study (mean, 45 months) with HIV-1 and 8 uninfected controls. Serum and cerebrospinal fluid (CSF) IgG and albumin levels of infected chimpanzees never exceeded those of controls. The CSF/serum albumin ratio was elevated in 1 of 18 infected chimpanzees compared to controls; however, all animals had an elevated ratio indicating a more open blood-brain barrier relative to humans. The intrathecal IgG production index was elevated in only 1 of 18 infected chimpanzees compared to controls. Identical serum and CSF IgG bands were found by isoelectric focusing in 2 of 8 controls and in 1 of 18 infected chimpanzees. None of these bands reacted with recombinant HIV-1 p24gag or gp 120env. HIV-1 was isolated from the peripheral blood of 4 of 18 infected chimpanzees but never from the paired CSF samples. Anti-HIV-1 antibody was detected by a enzyme-linked immunosorbent assay in 18 of 18 paired serum and CSF samples and by Western blot in 18 of 18 serum and 13 of 18 CSF samples from infected chimpanzees without a difference in pattern. Polymerase chain reaction analysis on brain tissue of one animal was negative for HIV-1 sequences. Our results demonstrate that, unlike human infection, chimpanzees inoculated with HIV-1 show no evidence of isolatable virus in the CSF and no evidence of intrathecal anti-HIV-1 antibody synthesis up to several years after experimental infection. The lack of CNS involvement may contribute to the delay or suppression of clinical disease in infected chimpanzees.