Lars Lindquist

Inhibition of leukocyte rolling with polysaccharide fucoidin prevents pleocytosis in experimental meningitis in the rabbit.

Inflammatory recruitment of leukocytes into the cerebrospinal fluid (CSF) during bacterial meningitis has been shown to contribute significantly to the neurological damage commonly associated with this serious disease. In this study we tested whether or not inhibition of leukocyte rolling, a precondition for firm leukocyte adhesion to vascular endothelium in vivo, may reduce CSF leukocyte recruitment and associated inflammatory changes in rabbits with experimental meningitis. As documented by intravital microscopy of small venules in the rabbit mesentery and tenuissimus muscle, leukocyte rolling was rapidly and profoundly reduced by intravenous treatment with the polysaccharide fucoidin, a homopolymer of sulfated L-fucose known to block the function of the leukocytic rolling receptor L-selectin. Moreover, fucoidin treatment dramatically reduced the accumulation of both leukocytes and plasma protein in the CSF of rabbits challenged intrathecally with pneumococcal antigen. These main findings thus illustrate that inhibition of leukocyte rolling, an early and obligatory step in the process of leukocyte extravasation, may be an effective therapeutic approach to attenuate leukocyte-dependent central nervous system damage in bacterial meningitis.

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

BACKGROUNDnTick-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.nnnOBJECTIVESnTo 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.nnnSTUDY DESIGNnThe 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.nnnRESULTSnAntibody 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.nnnCONCLUSIONSnCapture 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.

Sputum concentration improves diagnosis of tuberculosis in a setting with a high prevalence of HIV

Sputum microscopy for acid-fast bacilli (AFB), although relatively insensitive, is still the cornerstone of tuberculosis (TB) diagnosis in the developing world. Its diagnostic value has been eroded owing to the increasing number of HIV-related smear-negative pulmonary TB cases. Concentration of sputum by centrifugation after liquefaction with sodium hypochlorite is a possible means of increasing the sensitivity of direct microscopy. This procedure has been studied recently in developing countries although with conflicting results. The aim of our study, performed in 1996 in Addis Ababa, Ethiopia, was to evaluate the sensitivity of the concentration method in a large cohort of consecutive patients with suspected pulmonary TB. We show that the overall sensitivity increased from 54.2% using conventional direct microscopy to 63.1% after concentration (P < 0x0015). In HIV-positive patients, sensitivity increased from 38.5% before to 50.0% after concentration (P < 0x0034). The significant increase in yield of AFB in HIV-positive patients suggests that this method has a place in routine diagnosis of pulmonary TB in countries with a high prevalence of HIV.

Pharmacogenetic & Pharmacokinetic Biomarker for Efavirenz Based ARV and Rifampicin Based Anti-TB Drug Induced Liver Injury in TB-HIV Infected Patients

Background Implication of pharmacogenetic variations and efavirenz pharmacokinetics in concomitant efavirenz based antiviral therapy and anti-tubercular drug induced liver injury (DILI) has not been yet studied. We performed a prospective case-control association study to identify the incidence, pharmacogenetic, pharmacokinetic and biochemical predictors for anti-tubercular and antiretroviral drugs induced liver injury (DILI) in HIV and tuberculosis (TB) co-infected patients. Methods and Findings Newly diagnosed treatment naïve TB-HIV co-infected patients (nu200a=u200a353) were enrolled to receive efavirenz based ART and rifampicin based anti-TB therapy, and assessed clinically and biochemically for DILI up to 56 weeks. Quantification of plasma efavirenz and 8-hydroxyefaviernz levels and genotyping for NAT2, CYP2B6, CYP3A5, ABCB1, UGT2B7 and SLCO1B1 genes were done. The incidence of DILI and identification of predictors was evaluated using survival analysis and the Cox Proportional Hazards Model. The incidence of DILI was 30.0%, or 14.5 per 1000 person-week, and that of severe was 18.4%, or 7.49 per 1000 person-week. A statistically significant association of DILI with being of the female sex (pu200a=u200a0.001), higher plasma efavirenz level (pu200a=u200a0.009), efavirenz/8-hydroxyefavirenz ratio (pu200a=u200a0.036), baseline AST (pu200a=u200a0.022), ALT (pu200a=u200a0.014), lower hemoglobin (pu200a=u200a0.008), and serum albumin (pu200a=u200a0.007), NAT2 slow-acetylator genotype (pu200a=u200a0.039) and ABCB1 3435TT genotype (pu200a=u200a0.001). Conclusion We report high incidence of anti-tubercular and antiretroviral DILI in Ethiopian patients. Between patient variability in systemic efavirenz exposure and pharmacogenetic variations in NAT2, CYP2B6 and ABCB1 genes determines susceptibility to DILI in TB-HIV co-infected patients. Close monitoring of plasma efavirenz level and liver enzymes during early therapy and/or genotyping practice in HIV clinics is recommended for early identification of patients at risk of DILI.

Haemophilus influenzae and Streptococcus pneumoniae induce different intracerebral mRNA cytokine patterns during the course of experimental bacterial meningitis

Using in situ hybridization with radiolabelled oligonucleotide probes, we studied the mRNA expression of IL‐1β, IL‐4, IL‐6, IL‐10, IL‐12, tumour necrosis factor‐alpha (TNF‐α), TNF‐β, interferon‐gamma (IFN‐γ), and transforming growth factor‐beta (TGF‐β) in the brain during the lethal course of experimental meningitis in a rat model inoculated intracisternally with Haemophilus influenzae type b (Hib) or Streptococcus pneumoniae and in uninfected control rats inoculated with the same volume of PBS. The production of IL‐1β, IL‐4, IL‐6 and IFN‐γ was also evaluated by immunohistochemistry. In the brain of Hib‐inoculated rats, there was marked mRNA expression of IL‐1β, IL‐6, TNF‐α, IL‐12 and IFN‐γ. IL‐1β, IL‐6 and TNF‐α were up‐regulated throughout the observation period at 2, 8 and 18u2003h post‐inoculation (p.i.), with similar patterns of induction. The Th1 cytokines IFN‐γ and TNF‐β were up‐regulated within 8u2003h p.i. IL‐10 and TGF‐β were down‐regulated at 18u2003h p.i., while IL‐4 was not detected. In contrast, the brain of S. pneumoniae‐inoculated rats showed lower levels of IL‐1β, IL‐6 and TNF‐α, but higher levels of TNF‐β and detectable mRNA expression of IL‐4 when compared with Hib‐inoculated rats. IL‐12, IFN‐γ, IL‐10 and TGF‐β exhibited similar patterns of induction in the brains of Hib‐ and S. pneumoniae‐inoculated rats. At 18u2003h p.i., immunohistochemistry showed similar patterns of IL‐1β, IL‐4, IL‐6 and IFN‐γ as mRNA expression in the brains of Hib‐ and S. pneumoniae‐inoculated rats. The differences of cytokine profiles induced by the two bacterial strains may imply that different immunomodulating approaches should be considered, depending on etiology.

Anti-tuberculosis therapy-induced hepatotoxicity among Ethiopian HIV-positive and negative patients.

Background To assess and compare the prevalence, severity and prognosis of anti-TB drug induced hepatotoxicity (DIH) in HIV positive and HIV negative tuberculosis (TB) patients in Ethiopia. Methodology/Principal Findings In this study, 103 HIV positive and 94 HIV negative TB patients were enrolled. All patients were evaluated for different risk factors and monitored biochemically and clinically for development of DIH. Sub-clinical hepatotoxicity was observed in 17.3% of the patients and 8 out of the 197 (4.1%) developed clinical hepatotoxicity. Seven of the 8 were HIV positive and 2 were positive for HBsAg. Conclusions/Significance Sub-clinical hepatotoxicity was significantly associated with HIV co-infection (pu200a=u200a0.002), concomitant drug intake (pu200a=u200a0.008), and decrease in CD4 count (pu200a=u200a0.001). Stepwise restarting of anti TB treatment was also successful in almost all the patients who developed clinical DIH. We therefore conclude that anti-TB DIH is a major problem in HIV-associated TB with a decline in immune status and that there is a need for a regular biochemical and clinical follow up for those patients who are at risk.

Cross-Protective Capacity of Japanese Encephalitis (JE) Vaccines Against Circulating Heterologous JE Virus Genotypes

Current Japanese encephalitis vaccines are derived from strains of genotype III, yet heterologous genotypes are emerging in endemic areas. Inactivated vaccines given to European travelers were found to elicit protective levels of neutralizing antibodies against heterologous strains of genotypes I–IV.

Incidence and Prognosis of Meningitis due to Haemophilus influenzae, Streptococcus pneumoniae and Neisseria meningitidis in Sweden

The incidence, concomitant conditions and case fatality rate of Haemophilus influenzae (Hi) and pneumococcal meningitis and of invasive meningococcal infections were studied retrospectively in Sweden (population 8.4 million) for the years 1987-89, the period before vaccination against Hi type b started. A total of 1,019 cases with culture-verified infection were found. The incidence rates per 100,000 per year were 1.8 for Hi meningitis, 1.2 for pneumococcal meningitis and 1.0 for invasive meningococcal infections. The age-specific incidence was highest in the 3-23 months age group for the 3 bacterial species. Pneumococcal meningitis was common in individuals > or = 60 years and meningococcal infections in the age-group 10-24 years. A serious concomitant condition was known in 57% of all patients with pneumococcal meningitis while this was uncommon for the other organisms. The case fatality rate was 2% for Hi meningitis, 24% for pneumococcal meningitis and 10% for meningococcal infections. All 81 pneumococcal isolates which had been serotyped belonged to serotypes in the 23-valent pneumococcal vaccine. Of the meningococcal isolates, 65% belonged to serogroup B. In conclusion, the high incidence of Hib meningitis justifies general Hib vaccination. Development of a vaccine against N. meningitidis group B should have high priority. Furthermore, improved pneumococcal vaccines are needed for patients with predisposing conditions. The currently available pneumococcal polysaccharide vaccine seems to be underused.

A Single Dose of Vero Cell–Derived Japanese Encephalitis (JE) Vaccine (Ixiaro) Effectively Boosts Immunity in Travelers Primed With Mouse Brain–Derived JE Vaccines

The new Japanese encephalitis vaccine (JE-VC, Ixiaro) has replaced mouse brain–derived vaccines (JE-MB) associated with serious safety concerns. A single dose of JE-VC effectively boosted immunity in JE-MB–primed travelers. Current recommendations for booster vaccination should be reevaluated.

Molecular characterisation of two mumps virus genotypes circulating during an epidemic in Lithuania from 1998 to 2000

Summary.u2002An epidemic of mumps in Lithuania started in December 1998 and continued until May 2000. The total registered number of cases was about 11.000 of a total of 3,7 million inhabitants in Lithuania (29,7 cases/10000). Virus- containing samples were collected from 80 patients treated at the hospital of Kaunas from October 1999 until the end of the epidemic. Out of the 80 patients with parotitis, meningitis was observed in 11 patients and orchitis in 22 of 69 male patients. Twenty-seven virus strains were genotyped by nucleotide sequencing of the small hydrophobic (SH) protein gene, and the 57 amino acid sequences of the gene were deduced. Twenty-five virus strains belonged to the C genotype and two were of the D genotype. By phylogenetic analysis the virus strains causing meningitis grouped in a separate cluster, designated C1, within the C genotype. Another group of ten of the 25 genotype C strains exhibited an amino acid triplet at amino acid positions 28 to 30 of the protein, consisting of valine, alanine and serine, instead of the previously recognised valine, valine and serine combination of genotype C. The amino acid alanine at position 29 was found in combination with the amino acid serine at position 48. This variant was designated C2 and it was associated with parotitis. The amino acid alanine at position 29 and serine in position 48 of the C2 genotype may constitute a marker of low neurovirulence compared to other genotype C strains.