Recombinant or peptide antigens in the serology of Lyme arthritis in children

The performance of ELISAs with the recombinant antigens decorin-binding protein A (DbpA), DbpB, and BBK32 (from Borrelia afzelii, B. garinii, and B. burgdorferi sensu stricto) and VlsE peptide antigen invariable region 6 (IR(6)) were evaluated in the serodiagnosis and follow-up of children with Lyme arthritis (LA). Serum samples were obtained from 52 children with clinically typical and serologically confirmed LA. In IgG ELISAs, at diagnosis, 50 samples were positive for BBK32, 51 for DbpA, 40 for DbpB, and 51 for IR(6). In the posttreatment follow-up, the rate of decline of the antibodies to the recombinant protein antigens or to IR(6) did not appear useful in the prediction of the treatment response or the clinical course of LA. Yet, IR(6) seems to have the greatest potential to be used universally in the diagnostic serology of Lyme borreliosis (LB). Alternate to that, the use of several specific borrelial antigens, in parallel, might improve the accuracy of serology for LB.

Complement inhibitor factor H binding to Lyme disease spirochetes is mediated by inducible expression of multiple plasmid-encoded outer surface protein E paralogs

Borrelia burgdorferi spirochetes can circumvent the vertebrate host's immune system for long periods of time. B. burgdorferi sensu stricto and B. afzelii, but not B. garinii, bind the complement inhibitor factor H to protect themselves against complement-mediated opsonophagocytosis and killing. We found that factor H binding and complement resistance are due to inducible expression of a wide repertoire of outer surface protein E (OspE) lipoproteins variably called OspE, p21, ErpA, and ErpP. Individual Borrelia strains carry multiple plasmid-encoded OspE paralogs. Together the OspE homologs were found to constitute an array of proteins that bind factor H via multiple C-terminal domains that are exposed outwards from the Borrelial surface. Charged residue substitutions in the key binding regions account for variations between OspE family members in the optimal binding pH, temperature, and ionic strength. This may help the spirochetes to adapt into various host environments. Our finding that multiple plasmid-encoded OspE proteins act as virulence factors of Borrelia can provide new tools for the prevention and treatment of borreliosis.

Infectious background of patients with a history of acute anterior uveitis

OBJECTIVE

To study the infectious background of patients with a history of acute anterior uveitis (AAU) and healthy control subjects.

METHODS

Sixty four patients with previous AAU and 64 sex and age matched controls were studied. Serum antibodies to Salmonellae, Yersiniae, Klebsiella pneumoniae, Escherichia coli, Proteus mirabilis, Campylobacter jejuni, and Borrelia burgdorferi were measured using enzyme linked immunosorbent assay (ELISA), and antibodies to Chlamydia trachomatis and Chlamydia pneumoniae by microimmunofluorescence test. Peripheral blood mononuclear cells (PBMCs), separated by density gradient centrifugation, were studied for Salmonella and Yersinia antigens by means of an immunofluorescence test, and for C pneumoniae DNA with a polymerase chain reaction (PCR).

RESULTS

Neither prevalence nor levels of single microbial antibodies studied differed between the patients and control subjects, or between subgroups of patients created on the basis of clinical characteristics. In logistic regression analysis, the high number of recurrences (>10) of AAU was independently related to the presence of single or multiple bacterial antibodies (p=0.04). None of the PBMC samples of the patients were positive for Yersinia or Salmonella antigens. C pneumoniae PCR was positive in a patient who was negative for C pneumoniae antibodies.

CONCLUSION

Although neither the prevalence nor the levels of single microbial antibodies studied differed between the patients and the controls, current data suggest that the presence of single or multiple antibodies in patients with many recurrences of AAU compared with patients with none or few recurrences may be a sign of repeated infections, antigen persistence, or raised innate immune responsiveness.

Recombinant OspC from Borrelia burgdorferi sensu stricto, B. afzelii and B. garinii in the serodiagnosis of Lyme borreliosis

Genes for the outer-surface protein C (OspC) from three north European human isolates of Borrelia burgdorferi sensu stricto, B. afzelii and B. garinii were cloned and sequenced. Polyhistidine-tagged recombinant OspC (rOspC) proteins were produced in Escherichia coli and used, after biotinylation, as antigens on streptavidin-coated plates in enzyme-linked immunosorbent assays (ELISA). In IgM ELISA, 30% (5/17) and 35% (6/17) of patients with erythema migrans (EM) in the acute or convalescent phase, respectively, reacted with one to three rOspCs. Of the patients, 53% (8/15) with neuroborreliosis (NB) and 53% (8/15) with Lyme arthritis (LA) had IgM antibodies to OspC. The immunoreactivity was stronger against rOspC from B. afzelii and B. garinii than against rOspC from B. burgdorferi sensu stricto. In early Lyme borreliosis (LB), rOspC and flagella performed equally well in detecting IgM antibodies. Cross-reactive antibodies to rOspC were observed in serum samples from patients with rheumatoid factor positivity and with syphilis or Epstein-Barr virus (EBV) infection. In IgM ELISA, thiocyanate in the serum dilution buffer reduced EBV-associated non-specific positive reactions. Of the patient sera examined in IgG ELISA, 30% (5/17) with EM in the acute phase, 35% (6/17) with EM in the convalescent phase, 33% (5/15) with NB and 60% (9/15) with LA were positive. Because of the heterogeneity of OspC, a polyvalent antigen with several OspC variants from at least B. afzelii and B. garinii is needed to improve the sensitivity of OspC ELISA in the serodiagnosis of LB in Europe.

Cloning of the gene encoding the decorin-binding protein B (DbpB) in Borrelia burgdorferi sensu lato and characterisation of the antibody responses to DbpB in Lyme borreliosis

A genome walking technique was applied to borrelial DNA to clone the gene encoding decorin-binding protein B (DbpB) in Borrelia garinii and B. afzelii. Sequence analysis showed 62-67% identity of the predicted amino acid sequences of DbpB between the B. afzelii and B. garinii strains and B. burgdorferi sensu stricto. Within subspecies, the sequences were 99-100% identical. The respective recombinant DbpBs (rDbpBs) were produced and tested as antigens in an enzyme-linked immunosorbent assay (ELISA) for Lyme borreliosis (LB). In IgG ELISA, with rDbpBs as antigens, 11 (73%) of 15 adult patients with Lyme arthritis and 9 (64%) of 14 with neuroborreliosis were positive. Of children with Lyme arthritis, 40 (77%) of 52 were positive. All adult and paediatric patients with disseminated LB had high titres of anti-flagellin IgG antibodies. Seropositivity against rDbpB from B. garinii predominated, 39 (65%) of 60 of the positive samples reacting with rDbpB from B. garinii. In patients with erythema migrans, IgM antibodies to rDbpB were detected in 1 (4%) of 23 and IgG antibodies in 6 (26%) of 23. These results indicate that DbpB may be a useful antigen in the IgG serology for disseminated LB. The high inter-species sequence heterogeneity observed indicates that a combination of the variant DbpBs should be included in the antigen set to cover all the relevant borrelial subspecies in the serodiagnosis of LB.

Lyme borreliosis and facial paralysis--a prospective analysis of risk factors and outcome

PURPOSE

To evaluate the incidence of Lyme borreliosis in patients with acute idiopathic facial paralysis with special emphasis on the risk factors that explain the poor outcome of facial paralysis and occurrence of Lyme borreliosis.

MATERIALS AND METHODS

During a 2-year period, we prospectively studied 503 consecutive patients with acute idiopathic facial paralysis for the presence of Lyme borreliosis. We screened the patients for antibodies to Borrelia burgdorferi and for symptoms or signs related to Lyme borreliosis. Chi-square and logistic regression tests were used for the statistical analysis. Special attention was paid to strict criteria for the diagnosis of Lyme borreliosis.

RESULTS

Eleven (2.2%) of the 503 patients with facial paralysis had Lyme borreliosis. Fever, headache, pharyngalgia, enlarged cervical lymph nodes, bilateral paralysis, and arthralgia were more common in patients with Lyme borreliosis than in those without it. In the logistic regression modeling the best combination of explanatory variables for predicting the occurrence of Lyme borreliosis included summer season at the onset of facial paralysis, presence of enlarged cervical lymph nodes, and arthralgia. The best combination of explanatory variables to predict the poor outcome of facial paralysis was total paralysis of facial nerves, recurrent facial paralysis, and hyperacusis.

CONCLUSIONS

Lyme borreliosis is an important infectious cause of facial paralysis. In our study, 11 of 503 patients with acute idiopathic facial paralysis had Lyme borreliosis. The screening for serum antibodies in addition to the thorough evaluation of the history of the patient and of the patient's clinical signs or symptoms possibly linked with Lyme borreliosis, are essential when diagnosing Lyme borreliosis.

Recombinant BBK32 protein in serodiagnosis of early and late Lyme borreliosis

Borrelial protein BBK32 was evaluated as an antigen in the serodiagnosis of early and disseminated Lyme borreliosis (LB). bbk32 was cloned and sequenced from eight isolates of the three pathogenic Borrelia species. The identities between the amino acid sequences of the BBK32 proteins from Borrelia burgdorferi sensu stricto, B. garinii, and B. afzelii isolates were 71 to 100%. By immunoglobulin G (IgG) Western blotting (WB) or enzyme-linked immunosorbent assay (ELISA), up to 74 and 100% of acute- and convalescent-phase samples, respectively, from 23 patients with erythema migrans (EM) were positive for recombinant BBK32 protein from B. afzelii. In the serology of disseminated LB, the three variant BBK32 antigens cross-reacted. In total, 14 of 14 samples from patients with neuroborreliosis and 15 of 15 samples from patients with Lyme arthritis were positive. The specificities of the IgG ELISA with the variant BBK32 antigens for EM and disseminated borreliosis were 81 to 92% and 89 to 95%, respectively. Our findings indicate that the BBK32 proteins are promising serodiagnostic antigens for the detection of early and disseminated LB but that variant BBK32 proteins may be needed either in parallel or in combination with an immunoassay for LB to cover all the relevant borrelial species that cause the disease.

Species-specific serodiagnosis of Lyme arthritis and neuroborreliosis due to Borrelia burgdorferi sensu stricto, B. afzelii, and B. garinii by using decorin binding protein A

The antigenic potential of decorin binding protein A (DbpA) was evaluated in serodiagnosis of human Lyme borreliosis (LB). The dbpA was cloned and sequenced from the three pathogenic Borrelia species common in Europe. Sequence analysis revealed high interspecies heterogeneity. The identity of the predicted amino acid sequences was 43 to 62% among Borrelia burgdorferi sensu stricto, B. afzelii, and B. garinii. The respective recombinant DbpAs (rDbpAs) were produced and tested as antigens by Western blotting and enzyme-linked immunosorbent assay (ELISA). One hundred percent of patients with neuroborreliosis (NB) and 93% of patients with Lyme arthritis (LA) reacted positively. Sera from the majority of patients reacted with one rDbpA only and had no or low cross-reactivity to other two variant proteins. In patients with culture-positive erythema migrans (EM), the sensitivity of rDbpA immunoglobulin G (IgG) or IgM ELISA was low. The DbpA seems to be a sensitive and specific antigen for the serodiagnosis of LA or NB, but not of EM, provided that variants from all three pathogenic borrelial species are included in the combined set of antigens.

Recombinant flagellin A proteins from Borrelia burgdorferi sensu stricto, B. afzelii, and B. garinii in serodiagnosis of Lyme borreliosis

Genes for flagellin A (FlaA) proteins from European borrelial strains of Borrelia burgdorferi sensu stricto, B. afzelii, and B. garinii were cloned and sequenced. An identity of 92 to 93% was observed in the flaA sequences of the different species. Polyhistidine-tagged recombinant FlaA (rFlaA) proteins were produced in Escherichia coli and used as antigens in Western blotting (WB) and enzyme-linked immunosorbent assay (ELISA). In immunoglobulin G (IgG) WB, 71% (10 of 14) of the sera from neuroborreliosis and 86% (12 of 14) of those from Lyme arthritis patients reacted with one to three rFlaAs. In IgG ELISA, 74% (14 of 19) and 79% (15 of 19) of patients with neuroborreliosis and arthritis, respectively, were positive. The immunoreactivity in local European patient sera was stronger against rFlaA from B. garinii and B. afzelii than against rFlaA from B. burgdorferi sensu stricto. Neither IgG nor IgM ELISA was sensitive in the serodiagnosis of erythema migrans. Serum samples from patients with syphilis and systemic lupus erythematosus showed mild cross-reactivity in IgG tests. Sera from Yersinia enterocolitica or beta-hemolytic Streptococcus infections showed only occasional responses. With IgM ELISA, 58% (11 of 19) and 37% (7 of 19) of patients with neuroborreliosis and arthritis, respectively, were positive. Cross-reactive antibodies to FlaA, especially in serum samples from patients with rheumatoid factor positivity and Epstein-Barr virus infection, reduced the specificity of IgM serodiagnosis. Therefore, rFlaA seems to have a limited role for IgM serodiagnosis, yet rFlaA might be useful in the IgG serodiagnosis of disseminated Lyme borreliosis.

Evaluation of treatment responses in late Lyme borreliosis on the basis of antibody decrease during the follow-up period

The purpose of this study was to identify a serological marker of successful treatment as distinct from treatment failure in late Lyme borreliosis. Consecutive serum samples from 68 treated patients with late Lyme borreliosis were analyzed during a 1-2 year follow-up period after the start of treatment. End-point enzyme immunoassay titres of IgG1, IgG2, IgG3, and combined IgG1+3 subclasses against a sonicate antigen of Borrelia burgdorferi were determined and compared to the IgG antibody response against Borrelia burgdorferi flagella. Individual half-lives of the antibody levels were calculated for each patient. The half-life values were compared to the patients' clinical outcome in order to find a serological marker of remaining disease activity or relapse. The levels of combined IgG1+3 subclass antibodies against the sonicate antigen and the individual levels of IgG1, IgG2, and IgG3 antibodies did not change significantly after treatment. In contrast, antibodies to flagella decreased markedly after successful treatment, with a half-life of 112+/-92 days (arithmetic mean value +/- SD). This was significantly shorter than the half-life after unsuccessful treatment (271+/-151 days), (P<0.0001). The decrease was observed mainly in IgG1 and IgG4 responses to flagella, less so for IgG2 or IgG3. The results suggest that a rapid decrease in flagella antibodies can serve as a marker for a successful treatment of Lyme borreliosis.

IgG subclass distribution of antibodies after vaccination of adults with pneumococcal conjugate vaccines

The serum IgG subclass response of adults to Streptococcus pneumoniae (Pnc) capsular polysaccharides (PS) 6B, 14 and 23F was measured for four Pnc vaccines: the 23-valent PS vaccine or PS-protein conjugates with diphtheria toxoid (PncD), tetanus protein (PncT) or CRM197 protein (PncCRM) carriers. A standardized enzyme-linked immunosorbent assay specific for IgG subclasses was employed. This assay uses pneumococcal reference serum, lot 89-SF, to which anti-Pnc PS IgG subclass concentrations have been assigned. Both IgG1 and IgG2 responses were more frequent and higher in the conjugate groups than in the PS group. IgG subclasses in subjects vaccinated with PS displayed similar IgG2 predominant distribution previously observed in both natural and vaccine-induced antibodies. Antibodies induced by PncT, however, had a significantly altered IgG2/IgG1 ratio (P < 0.05), with a higher proportion of IgG1.

The laboratory diagnosis of ocular Lyme borreliosis

BACKGROUND

A study was carried out to evaluate indirect enzyme-linked immunosorbent assay (ELISA), immunoblot analysis, and polymerase chain reaction (PCR) in the diagnostic work-up of ocular Lyme borreliosis.

METHODS

Twenty patients with ocular Lyme borreliosis were examined. IgG and IgM antibodies to Borrelia burgdorferi were measured by ELISA in serum, and in cerebrospinal fluid (CSF) when indicated, and immunoblot analysis of B. burgdorferi IgG antibodies in serum was performed. A nested PCR was used to detect a segment of a gene coding for B. burgdorferi endoflagellin. The samples used in PCR testing were serum and CSF and in isolated cases conjunctiva and vitreous.

RESULTS

Seventeen patients had elevated Borrelia antibodies in serum or CSF by ELISA. Seven patients, including two with negative ELISA, had a positive immunoblot. Seven of the 13 patients in whom PCR was examined during clinically active disease had a positive PCR result. Immunoblot analysis gave a negative result from the sera of five PCR-positive patients.

CONCLUSIONS

For efficient diagnosis of ocular Lyme borreliosis, immunoblot analysis and PCR should be used in addition to ELISA. A positive PCR seems to be associated with a negative immunoblot.

Inadequate dosaging in general practice of tricyclic vs. other antidepressants for depression

Several prescription database studies suggest major differences between antidepressants in the proportion of patients in general practice treated with doses likely to elicit a true drug response. However, in these studies it has been difficult to differentiate prescriptions for depression from those for other indications, or to distinguish lower starting doses from the final treatment doses. We investigated possible differences between types of antidepressant in the proportions of patients receiving adequate treatment doses for depression from the primary health care services of Helsinki. Doctors at 22 (71%) of the 31 health centres in Helsinki were surveyed with regard to their antidepressant prescriptions over a period of 2 working weeks. There were marked differences in dosaging adequacy between the various types of antidepressant prescribed for depression at final treatment doses. Overall, 71% of the prescriptions for the tricyclic antidepressants, but only 13% of those for the other antidepressants, mainly selective serotonin reuptake inhibitors, were for low doses that are generally considered to be ineffective (P<0.001). These findings endorse the emerging perception that, in general practice, tricyclic antidepressants are usually prescribed for depression in too low doses, and that a greater reliance on other antidepressants would probably improve the effectiveness of treatment in primary health care.

IgG subclass-specific antibodies in Chlamydia pneumoniae infections

IgG subclass-specific antibodies to Chlamydia pneumoniae and chlamydial lipopolysaccharide (LPS) were analysed in paired sera obtained from 15 patients with primary C. pneumoniae pneumonia and from 16 pneumonia patients with reinfection, as well as in single sera of 40 subjects with possible chronic C. pneumoniae infection and 40 healthy controls. The microimmunofluorescence (MIF) method was used to measure total IgG, IgM and IgG subclass-specific antibodies to C. pneumoniae protein antigens and enzyme immunoassay (EIA) to measure antibodies against the LPS antigen. By MIF, IgG1 antibodies to C. pneumoniae were demonstrated in all individuals of the 3 patient groups and also in all healthy controls. IgG2 subclass antibodies were not found by MIF. IgG3 antibodies were detected in 40% of patients with primary infection, in 31% of patients with reinfection, in 25% of those with chronic infection and in 8% of the controls. IgG4 antibodies were associated with acute C. pneumoniae infection and were found in 13% of primary infections and 31% of reinfections. The subclass pattern of LPS antibodies resembled that of protein antibodies measured by MIF: IgG1 was the most common subclass among the antibodies to LPS.

Paediatric facial paralysis caused by Lyme borreliosis: a prospective and retrospective analysis

The incidence of Lyme borreliosis (LB) was studied prospectively in 49 children (< 17 years of age) with 50 episodes of acute FP. In addition, 43 children with a history of FP (average follow-up of 5.2 y) were studied retrospectively for the outcome of FP and for the symptoms and signs of late LB. In the prospective study, 17 (34%) patients with FP proved to have acute LB. They all received antibiotic treatment and their FP had a favourable outcome. In the retrospective study the patients had had FP before the diagnostic tests for LB were available. Thus, none of the 43 patients had been diagnosed to have, or treated for, LB. The outcome of their FP had generally been favourable. None of them had any signs of late LB at the follow-up visit. Our results indicate that LB is a frequent cause of acute paediatric FP in an endemic area. In addition our data suggests that FP caused by LB in children has a favourable prognosis, even when left untreated.

Lyme borreliosis--an unusual cause of vertigo

A total of 2055 consecutive vertigo patients were examined in a prospective study in an area endemic for Lyme borreliosis for clinical signs of Lyme borreliosis or serum antibodies against Borrelia burgdorferi. Of these, 41 patients (2%) had positive levels of serum antibodies against B. burgdorferi. The incidence of seropositivity against B. burgdorferi among the vertigo patients did not differ from the incidence of the normal Finnish population. In addition to seropositivity the criteria used for Lyme borreliosis included previous erythema migrans, a positive polymerase chain reaction (PCR) or positive serum immunoblot. Eight patients were diagnosed as having Lyme borreliosis. This disease is a rare but possible cause of vertigo. Seropositivity alone is an insufficient finding for the diagnosis of Lyme borreliosis and should be supported by the clinical findings, the patient's history and other laboratory findings, such as immunoblotting or PCR. Although Lyme borreliosis seems to be a rare cause of vertigo, it must be kept in mind in the differential diagnosis of vertigo.

Assignment of immunoglobulin G1 and G2 concentrations to pneumococcal capsular polysaccharides 3, 6B, 14, 19F, and 23F in pneumococcal reference serum 89-SF

We describe standardization of an enzyme-linked immunosorbent assay (ELISA) for measuring immunoglobulin G1 (IgG1) and IgG2 concentrations of antibodies to pneumococcal capsular polysaccharide (Pnc PS). The ELISA uses a human pneumococcal reference serum pool, lot 89-SF, as a reference. IgG1 and IgG2 concentrations were assigned to antibodies to Pnc PS serotypes 3, 6B, 14, 19F, and 23F in 89-SF by ELISA using affinity-purified monoisotypic IgG1 and IgG2 preparations. The sum of IgG1 and IgG2 concentrations in 89-SF agrees well with the previously assigned IgG concentrations. The IgG1 and IgG2 values in 89-SF were used to measure antibodies to Pnc PS 6B, 14, and 23F in adult pre- and postimmunization sera and the sum of IgG1 and IgG2 concentrations correlated well with the IgG values. Furthermore, the IgG2/IgG1 ratio did not affect the detection of IgG1, the isotype usually represented by a lower concentration.

The etiology of uveitis: the role of infections with special reference to Lyme borreliosis

PURPOSE

To assess the distribution of different uveitis entities and to evaluate their associations with infections, especially Lyme borreliosis.

METHODS

During a one-year period 160 consecutive uveitis patients were evaluated in a university clinic. Selected tests were performed depending on the medical history of the patient and the clinical picture of the ocular inflammation.

RESULTS

Uveitis was classified into selected entities for 74.4% of the patients. A direct infection was suggested to be linked with uveitis in 23 patients (14.4%). Lyme borreliosis, toxoplasmosis, and herpetic infections were the most frequently seen, in seven patients (4.3%) each. All patients with Lyme uveitis had manifestations of the posterior segment of the eye, such as vitritis, retinal vasculitis, neuroretinitis, chorioretinitis, or optic neuropathy.

CONCLUSION

Infections are an important cause of uveitis in a university clinic. Lyme borreliosis is a newly recognised uveitis entity which should be kept in mind in the differential diagnosis of intermediate or posterior uveitis in areas endemic for Lyme borreliosis.

Antiphospholipid antibodies in children

Sera from children (n = 173) were tested for antiphospholipid antibodies (aPL) using an enzyme immunoassay detecting IgG anti-cardiolipin antibodies (GPL). Sera from adults (n = 100) were also tested. GPL were detected more frequently and at higher levels in children than in adults. Eighty-two per cent of the children and 27% of the adults tested positive (> or = 10 GPL Uml-1) for aPL (p < 0.001). Values of 45 GPLUml-1 or higher were detected in about 5% of the children, and 25 GPLUml-1 or higher in about 5% of the adults. Normal values should be adjusted accordingly.

Long-term follow-up of chronic Lyme neuroretinitis

PURPOSE

The authors report sequential fluorescein angiographic and color photographic findings of the fundi and response to treatment in a patient with chronic Lyme neuroretinitis.

METHODS

A Lyme enzyme-linked immunosorbent assay with purified 41-kd flagellin as antigen was used to detect immunoglobulin G and immunoglobulin M antibodies to Borrelia burgdorferi in serum, cerebrospinal fluid, and vitreous. The changes were documented by fluorescein angiography and color photography tests performed during a 5 1/2 year follow-up.

RESULTS

The diagnosis of Lyme neuroretinitis was based on the history of erythema migrans and positive Lyme enzyme-linked immunosorbent assay tests from cerebrospinal fluid and vitreous and by the exclusion of other infectious and systemic diseases and uveitis entities. Fluorescein angiography results disclosed bilateral chronic neuroretinal edema with areas of cystoid, patchy, and diffuse hyperfluorescence peripapillary and in the macular areas. The hyperfluorescent lesions enlarged despite a 9-month period of antibiotic therapy.

CONCLUSION

Lyme borreliosis may cause neuroretinitis with unusual angiographic findings. Chronic Lyme neuroretinitis may be unresponsive to antibiotic therapy.

Domain-specific antibodies against the B2 chain of laminin inhibit neuronal migration in the neonatal rat cerebellum

Although the spatial and temporal patterns of neuronal migration have been analyzed in great detail, little direct evidence is available as to what extracellular matrix molecules are involved. Because there is indirect evidence implicating the extracellular matrix protein laminin in neuronal migration, we investigated the effects of antibodies against a synthetic peptide derived from a neurite outgrowth domain of the B2 chain of laminin on neuronal migration in living cerebellar slices. We show by using infrared video microscopy that divalent Fab2 fragments of these antibodies inhibit granule neuronal movement in living slices of (P8) rat cerebellum. This inhibition of neuronal movement manifests itself by cessation of both radial and horizontal translocations of nuclei inside the granule neuronal processes. Fab2 fragments of antibodies against the intact (native) laminin molecule or Fab2 fragments from the preimmune serum do not affect nuclear translocation. Immunocytochemistry shows binding of the divalent Fab2 fragments of the B2 chain-specific antibodies to the Purkinje and Bergmann glial cell areas, and as punctate deposits in between the cells of the external granule cell layer. Native laminin antibodies bind to the basement membranes, and binding of the Fab2 fragments from the preimmune sera cannot be demonstrated. These results indicate that neuronal migration in the postnatal rat cerebellum in vivo involves nuclear translocation that can be inhibited by antibodies against a neurite outgrowth domain of the B2 chain of laminin. Thus, migration of cerebellar granule neurons may depend on the interaction between a neurite outgrowth domain of the B2 chain of laminin and neuronal cytoskeleton involved in nuclear movement.

Diagnosis and clinical characteristics of ocular Lyme borreliosis

PURPOSE

To establish a diagnosis, in a group of patients we studied the characteristics of ocular Lyme borreliosis.

METHODS

During a two-year period, 236 patients with prolonged external ocular inflammation, uveitis, retinitis, optic neuritis, or unexplained neuro-ophthalmic symptoms were examined for Lyme borreliosis. Antibodies to Borrelia burgdorferi were measured by indirect ELISA and western blot. Cerebrospinal fluid was also analyzed by polymerase chain reaction.

RESULTS

Ocular Lyme borreliosis was diagnosed in ten patients on the basis of medical history, clinical findings, and serologic test results. Results of ELISA disclosed that five patients were seropositive, two patients showed borderline reactivity, and three patients were seronegative. Four of the five patients with borderline or negative results by ELISA had a positive result by western blot analysis. In one seropositive patient, polymerase chain reaction verified a gene of B. burgdorferi endoflagellin from the vitreous and cerebrospinal fluid specimen. In five of the six patients with known onset of the Borrelia infection, the ocular disorder appeared as a late manifestation. Abnormalities of the posterior segment of the eye, such as vitreitis, retinal vasculitis, neuroretinitis, choroiditis, and optic neuropathy were seen in six patients. Bilateral paralytic mydriasis, interstitial keratitis, episcleritis, and anterior uveitis were seen in one patient each.

CONCLUSIONS

Late-phase ocular Lyme borreliosis is probably underdiagnosed because of weak seropositivity or seronegativity in ELISA assays. Ocular borrelial manifestations show characteristics resembling those seen in syphilis.

Antibodies against some bacterial antigens in children

The prevalence of bacterial antibodies was determined in 173 children aged 0-15 years. The prevalence of IgG Borrelia burgdorferi antibodies in titres > 500 in children less than 8 years of age was 6% while none of the older children had these antibodies in titres > 400. IgG Helicobacter pylori antibodies were detected only in children older than 6 years of age, with a prevalence of 6.5%, as were IgA H. pylori antibodies, with a prevalence of 3.7%. The prevalence of high-titre IgG Campylobacter jejuni antibodies was 1.2%, that of IgA 1.8% and IgM 1.2%. The prevalence of high-titre (> 500 IU/ml) antistreptolysin O was 3%, that of antistaphylolysin-alpha (> or = 4 IU/ml) 2% and that of anti-teichoic acid antibodies (titre 2) 2%. Low-titre Yersinia antibodies were detected in 2%. High-titre Bordetella pertussis antibodies were detected in 6% of recently vaccinated children and in 8% of children in their first years of school. In the latter, high-titre antibodies were mainly of the IgM and IgA classes. Altogether 35 children tested positive for bacterial antibodies other than Bordetella pertussis antibodies. Clinical evaluation revealed a possible infection, suggested by the antibody, in 5 (3%) of the children. Two (vaccinated) children had evidence of whooping cough. Eight of the 35 children with high-titre bacterial antibodies (23%) also had elevated levels of autoantibodies (but not autoimmune diseases).

Treatment of late Lyme borreliosis

The aim of this study was to develop a treatment for late Lyme borreliosis and to compare the clinical results with serological findings before and after treatment. It was done in the Aland Islands (population 25,000), a region endemic for Lyme borreliosis. The patients were the first consecutive 100 patients from the Aland Islands with late Lyme borreliosis. They were followed for at least 1 year after treatment. The clinical results of treatment were compared with results of analyses of flagellar IgG antibodies to Borrelia burgdorferi done at the time of diagnosis before treatment and up to 12 months afterwards. Short periods of treatment were not generally effective. The outcome was successful in four of 13 treatments with 14 days of intravenous ceftriaxone alone, in 50 of 56 assessable treatments with ceftriaxone followed by 100 days of amoxycillin plus probenecid, and in 19 of 23 completed treatments with ceftriaxone followed by 100 days of cephadroxil. Titres of IgG antibodies to B. burgdorferi flagella declined significantly after 6 and 12 months in the patients who had successful treatments. All patients whose final titres were less than 30% of the initial titre were in the successful group. Their titres usually remained above the upper limit of normal for a long time but a decline to a value of less than 30% of that before treatment was always a sign of cure.

Evaluation of protein-denaturing immunoassays for avidity of immunoglobulin G to rubella virus

Immunoassays have been recently developed that measure the avidity of IgG antibodies to complex microbial antigens and are suitable for serologic diagnosis of infectious diseases. In these avidity ELISAs, protein-denaturing agents are applied either as diluents of patient sera to prevent the immune complexing of IgG (diluting principle), or the preformed complexes are treated with the protein denaturants (eluting principle). We compared four protein denaturants previously used in such assays, in a diagnostic avidity ELISA for rubella IgG. Diethylamine, guanidine, thiocyanate, or urea were applied, by either principle at various concentrations, and thiocyanate, or urea were applied, by either principle at various concentrations, and thiocyanate at an optimum pH. Patient sera obtained recently after primary infection were distinguished from sera representing past rubella immunity by any protein denaturant tested by the eluting principle, which was superior to the diluting principle.

V-region-mediated binding of human Ig by protein A

The Fab-mediated "alternative" binding of Ig by staphylococcal protein A is a marker of a set of VH genes (a subset of family VH3 in man). We typed 115 monoclonal human Ig as alternative binders or nonbinders. The proportion of binders varied depending on the isotype, 35% in IgM but only 11-13% in IgA1 and IgG3. It was 28% among lambda-chain-bearing but 16% among kappa-bearing monoclonal Ig. Independent estimates of the proportions bound were obtained by studying polyclonal Ig of 10 healthy adults. The proportions bound were close to those observed in the study of monoclonal Ig (the means were IgM 32%, IgA1 13%, IgA2 24%, IgG3 14%). A higher proportion of infant than adult Ig was bound by protein A. Also, the proportion was less isotype-dependent in infants than in adults. At the age of 4 mo, 47% of IgM was bound (mean of 10 children), the values of other isotypes were: IgA1 35%, IgA2 39%, and IgG3 38%. At the age of 14 mo the proportion of alternative binders had decreased but was still far from adult values. We propose that ontogenically early ("virgin") B cells, besides being rich in IgM and lambda-chain producers, are rich in producers of alternative binders. A subsequent selection reduces the proportion of these B cells so that in ontogenically most developed B cell populations, e.g., those producing IgA1 kappa, such cells make up only about 10% of the total.

V-region-mediated binding of human Ig by protein A

The Fab-mediated "alternative" binding of Ig by staphylococcal protein A is a marker of a set of VH genes (a subset of family VH3 in man). We typed 115 monoclonal human Ig as alternative binders or nonbinders. The proportion of binders varied depending on the isotype, 35% in IgM but only 11-13% in IgA1 and IgG3. It was 28% among lambda-chain-bearing but 16% among kappa-bearing monoclonal Ig. Independent estimates of the proportions bound were obtained by studying polyclonal Ig of 10 healthy adults. The proportions bound were close to those observed in the study of monoclonal Ig (the means were IgM 32%, IgA1 13%, IgA2 24%, IgG3 14%). A higher proportion of infant than adult Ig was bound by protein A. Also, the proportion was less isotype-dependent in infants than in adults. At the age of 4 mo, 47% of IgM was bound (mean of 10 children), the values of other isotypes were: IgA1 35%, IgA2 39%, and IgG3 38%. At the age of 14 mo the proportion of alternative binders had decreased but was still far from adult values. We propose that ontogenically early ("virgin") B cells, besides being rich in IgM and lambda-chain producers, are rich in producers of alternative binders. A subsequent selection reduces the proportion of these B cells so that in ontogenically most developed B cell populations, e.g., those producing IgA1 kappa, such cells make up only about 10% of the total.

Late Lyme borreliosis: epidemiology, diagnosis and clinical features

Lyme borreliosis is endemic in the Aland Islands. Exposure of the inhabitants to bites of the tick Ixodes ricinus is heavy. The purpose of this study was to describe symptoms and signs of patients with late Lyme borreliosis in this area, and to correlate the findings with the epidemiological setting. The first 100 consecutive patients with late Lyme borreliosis found in the region since 1984 are included in this study. Neurological, articular and muscular symptoms and signs dominate. General screening for Lyme disease is not recommended in the area due to uncertainty about how to deal with seropositive healthy persons in this heavily exposed population. The recognition and prompt treatment of erythema migrans and other manifestations of primary Lyme borreliosis is important in order to avoid the late stages of the disease. Treatment of all those suffering tick-bites with an antibiotic would be an option in view of the incidence of infected ticks, but cannot be considered because tick-bites are extremely common among the inhabitants. The region would be suitable for general immunization against Borrelia burgdorferi if the means for doing this becomes available in the future.

HIV-1 specificity of cerebrospinal fluid and serum IgG, IgM, and IgG1-G4 antibodies in relation to clinical disease

The reactivities of intrathecal and serum IgG and IgM, and IgG1-4 subclass antibodies to various HIV-1 proteins were assessed by immunoblotting at various stages of HIV-1 infection. All patients were examined neurologically including CT and/or MRI, and with HIV-1-specific and nonspecific tests of the cerebrospinal fluid (CSF). In early infection, the occurrence of anti-gag antibodies in both CSF and serum was higher than that of anti-pol antibodies among all IgG subclasses (P < 0.05). Also in late infection, anti-gag IgG1 response was most frequent (P < 0.04), while anti-gag IgG3 and IgG4 reactivities predominated over similar anti-pol antibodies (P < 0.05, respectively). Of anti-pol reactivities, in the CSF of subjects at early infection anti-p32 IgG and IgG1 antibodies were more frequent than in patients at late stages (P < 0.015). In late infection, however, the occurrence of anti-p64 IgM and IgG2-4 antibodies of both CSF and serum was higher than at early stages (P = 0.014). Regarding anti-env response, in patients with advanced infection, the CSF and serum IgG subclass reactivity against gp120 was restricted to IgG1. The CSF of individual patients with HIV encephalopathy showed a higher or similar occurrence of polyisotypic anti-gag and anti-pol IgG3 antibodies than corresponding serum. These results indicate association between declining frequency of anti-pol p32 and anti-env gp120 antibodies and severity of HIV-1 disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Efficient secretion of murine Fab fragments by Escherichia coli is determined by the first constant domain of the heavy chain

Fab fragments of IgG1 and IgG3 subclass antibodies which bind to 2-phenyloxazolone (Ox) were produced in Escherichia coli. The signal sequences of the Fd and L chains were correctly processed, the fragments were secreted into the periplasmic space and released into the culture medium upon prolonged cultivations. The yields of active Ox IgG1 and Ox IgG3 Fab fragments after one-step purification from the culture medium by affinity chromatography were 2 micrograms/ml and 0.5 micrograms/ml, respectively. The majority of the purified Ox IgG1 Fab was properly assembled, but in the case of Ox IgG3, the preparation was found to consist of a complete L chain and C-terminally degraded fragments of the Fd chain. A deletion up to the interchain disulfide bond in the first constant domain (CH1) of the Ox IgG3 Fd chain led to proper assembly of the truncated Fab fragment. The production level of the truncated fragment was comparable to that of the Ox IgG1 Fab and its hapten-binding activity similar to that of the idiotype monoclonal antibody. The temperature stability of the Ox IgG1 Fab was similar to that of the intact antibody. However, both of the Ox IgG3 Fab fragments showed reduced stability, suggesting that the CH1 domain contributes significantly to the thermal stability of the Fab fragment.

Half-life of the maternal IgG1 allotype in infants

The residence time of maternal IgG1 in the circulation of infants was measured by monitoring f-allotypic IgG1 or f-positive tetanus toxoid antibody in genetically G1mf-negative infants. G1ma-positive maternal tetanus toxoid antibody was similarly monitored in genetically a-negative infants. Blood samples were taken from infants at the age of 1-3 days, ca. 4 months, and ca. 6 months. An exponential decay at the same rate took place from age 1-3 days to 4 months and for the 2 subsequent months. The average concentration of the maternal IgG1 had dropped to ca. 10% of the 1- to 3-day value in 4 months and to ca. 3% in 6 months. The drop was due mainly to clearance but partly also to the weight increase of the child (doubling in 6 months). By correcting for the weight increase, we calculated that ca. 17 and 7% of the original maternal IgG1 was still present at ages 4 and 6 months, respectively. The average half-life of the maternal IgG1 was thus 48.4 days. The concentration of endogenous IgG1 in the cord blood was determined by studying a separate series of mother-newborn pairs. Assuming that cross-reactions of antiallotype reagents had no effect, the highest measured concentration of f-positive IgG1 in infants of f-negative mothers was 10 mg/L, half a percent of adult heterozygote values. Crossreaction may have played a role, however, and the value must be considered the upper limit of the true concentration.

The alternative binding site for protein A in the Fab fragment of immunoglobulins

Twenty-six new human or murine monoclonal immunoglobulins (IgM, IgA, murine IgG1 or human IgG3) with a known V-region sequence were tested for alternative (non-Fc) binding to Staphylococcal protein A. Seven of them did not bind at all. Four immunoglobulins (all mouse IgG1) were bound but easily eluted (at pH 6). They were probably bound via the Fc part. All eleven were classified as negative for alternative binding. Fifteen immunoglobulins were found to bind more firmly; they came off the protein A column at pH 4-3 (alternative binders). Amino acid sequences of immunoglobulins that have been typed in the present work or earlier (25 binders and 26 non-binders) were compared. The light chain, the C region of the heavy chain and the D and JH segments look irrelevant for alternative binding. The N-terminal portion (amino acids 1-94) of the H chain probably forms the ligand of protein A. A peptide making the ligand cannot be reliably localized within this stretch but binder proteins had a high homology in residues 6-29. All mouse immunoglobulins expressing VH genes of families J606 or S107 were alternative binders; those expressing other families were non-binders.

Neuronal migration in cerebellar microcultures is inhibited by antibodies against a neurite outgrowth domain of laminin

The functional role of laminin in neuronal migration was investigated by using polyclonal antibodies or their divalent (Fab')2 fragments to a neurite outgrowth promoting domain of the B2 chain of laminin in a cerebellar microculture system widely recognized as a model for neuronal migration. We show here that these antibodies or their (Fab')2 fragments totally inhibit migration of the mouse cerebellar granule cells along the glial and other neuronal cell processes. Antibodies to native laminin or other control antibodies have no inhibitory effect. Immunocytochemical analysis of the cerebellar microcultures indicates that the functional role of these antibodies may relate to the fact that the punctate deposits of laminin and its neurite outgrowth promoting domain accumulate in between the migrating neurons and the glial cells. These data provide the first direct evidence for the functional role of laminin and its neurite outgrowth domain in neuronal migration in the mammals. They further suggest that a neuronal cell surface contact with the extracellular deposits of a neurite outgrowth domain of the B2 chain of laminin may mediate neuronal-glial interactions.

Increased occurrence of free immunoglobulin light chains in cerebrospinal fluid and serum in human immunodeficiency virus-1 infection

The presence of free immunoglobulin light chains (FLCs) in the cerebrospinal fluid (CSF) and sera of patients with human immunodeficiency virus-1 (HIV-1) infection, multiple sclerosis (MS), and neurologically healthy control individuals was investigated by paying special attention to ensure that only truly free light chains would be detected. The FLCs were extracted by specifically binding them to Sepharose-coupled anti-FLC monoclonal antibodies, and thereafter they were electrophoresed and immunoblotted with monoclonal antibodies to both light chain (LC) isotypes. A frequent occurrence of kappa and lambda FLCs was found in both CSF and sera of HIV-1 infected patients. In HIV-1 infection and in MS, the frequency of FLCs of the CSF was equal. In healthy controls, only occasional weak FLCs were observed in either CSF or serum. FLC bands of the CSF from patients with HIV-1 infection tended to be more intensive than those of the appropriately diluted sera. Both intrathecal synthesis of FLCs and their transudation from sera through the impaired blood-brain barrier (BBB) may contribute to this. Increasing severity of general HIV-1 infection was accompanied by an increase of FLC intensity in sera. A qualitative demonstration of FLC in the CSF may be meaningful only in the absence of altered BBB function.

Mouse Ig coded by VH families S107 or J606 bind to protein A

Twenty-five monoclonal mouse Ig (5 IgA, 7 IgM, and 13 IgG1) were tested for binding to staphylococcal protein A. They were allowed to attach to protein A Sepharose column at pH 8.0 and were then eluted with a pH gradient from approximately 7.5 to 3.0. Five of them (IgM or IgA) did not bind. Ten came off with pH approximately 6. They were all IgG1, and were probably bound (weakly) via the Fc portion. The remaining 10 (3 IgA, 4 IgM, and 3 IgG1) were more firmly bound; they came off with pH-values ranging from 5.0 to 3.5. They all expressed VH genes of families J606 or S107, whereas all the 15 Ig that were not firmly bound expressed VH genes of six other families. The VL domains seem to be unimportant for protein A binding inasmuch as a firmly binding and a weakly binding IgG1 antibody share identical VK domains. VH sequences of protein A-binding and nonbinding Ig were compared. No likely peptide sequences were found that might make the ligand for protein A.

Mouse Ig coded by VH families S107 or J606 bind to protein A

Twenty-five monoclonal mouse Ig (5 IgA, 7 IgM, and 13 IgG1) were tested for binding to staphylococcal protein A. They were allowed to attach to protein A Sepharose column at pH 8.0 and were then eluted with a pH gradient from approximately 7.5 to 3.0. Five of them (IgM or IgA) did not bind. Ten came off with pH approximately 6. They were all IgG1, and were probably bound (weakly) via the Fc portion. The remaining 10 (3 IgA, 4 IgM, and 3 IgG1) were more firmly bound; they came off with pH-values ranging from 5.0 to 3.5. They all expressed VH genes of families J606 or S107, whereas all the 15 Ig that were not firmly bound expressed VH genes of six other families. The VL domains seem to be unimportant for protein A binding inasmuch as a firmly binding and a weakly binding IgG1 antibody share identical VK domains. VH sequences of protein A-binding and nonbinding Ig were compared. No likely peptide sequences were found that might make the ligand for protein A.

Antigenicity of dextran-protein conjugates in mice. Effect of molecular weight of the carbohydrate and comparison of two modes of coupling

Protein conjugates of polysaccharides or their breakdown products are being used as improved "T-dependent" vaccines. We tried to define optimal characteristics of future conjugate vaccines by testing the immunogenicity of thirteen conjugates of alpha 1-6 dextran and chicken serum albumin in mice (BALB/c and CBA). All conjugates induced stronger antidextran antibody responses than the polysaccharide, and a fair proportion of these antibodies were IgG. However, there was a range of antigenicities. Consistently strong responses were obtained with conjugates that carried small dextran molecules (m.w. 1000 to 4000) coupled to the protein via the reducing end. Modification of such an "optimal" conjugate either by increasing the size of the saccharide to 40,000 Da, or by permitting multiple attachments of the saccharide molecule to the protein, reduced its antigenicity. Carbohydrate/protein ratios varying from 0.17 to 0.49 were associated with excellent antidextran responses.

Antigenicity of dextran-protein conjugates in mice. Effect of molecular weight of the carbohydrate and comparison of two modes of coupling

Protein conjugates of polysaccharides or their breakdown products are being used as improved "T-dependent" vaccines. We tried to define optimal characteristics of future conjugate vaccines by testing the immunogenicity of thirteen conjugates of alpha 1-6 dextran and chicken serum albumin in mice (BALB/c and CBA). All conjugates induced stronger antidextran antibody responses than the polysaccharide, and a fair proportion of these antibodies were IgG. However, there was a range of antigenicities. Consistently strong responses were obtained with conjugates that carried small dextran molecules (m.w. 1000 to 4000) coupled to the protein via the reducing end. Modification of such an "optimal" conjugate either by increasing the size of the saccharide to 40,000 Da, or by permitting multiple attachments of the saccharide molecule to the protein, reduced its antigenicity. Carbohydrate/protein ratios varying from 0.17 to 0.49 were associated with excellent antidextran responses.

MAC technique (morphology antibody chromosomes) in phenotypic identification of proliferating NK and T cells in interleukin-2-stimulated lymphocyte cultures

Human peripheral blood lymphocytes were activated with recombinant interleukin 2 (rIL-2) and cultured in fetal calf serum (FCS)- or human-AB-serum-supplemented media. Proliferative cells were identified by the MAC technique (morphology antibody chromosomes) which enables the immunoenzymatic identification of both mitotic and non-proliferating cells in unfractionated lymphocyte populations. The results indicate that the phenotype of more than 90% of proliferative lymphocytes can be characterized by using antibodies against T cells and NK cells. Substantial mitotic activity of CD4-positive (CD4+) T cells was observed only in FCS-supplemented cultures, whereas in serum-free or human-AB-serum-supplemented cultures mostly CD8+ T cells and NK cells proliferated. The proportion of NK cells among all mitotic cells varied between 14 and 32%. Interestingly, in unfractionated cultures approximately 13% NK cells entered mitoses in the presence of rIL-2, suggesting that the poor proliferative capacity of purified NK cells demonstrated previously may be due to the lack of accessory stimulatory signals. The proliferation of B cells was minimal in all experiments. The MAC technique is a useful addition to the techniques by which lymphocyte growth regulation is monitored.

Lyme borreliosis in Finland in 1986-1988

In 1986-1988 there were 123 patients with positive serology for Lyme borreliosis out of 4000 sera referred to the Department of Bacteriology and Immunology, University of Helsinki. Of the 63 patients with positive serology in 1986-1987 20 showed a predominant involvement of the nervous system, 18 complained of joint symptoms and 11 patients merely showed a skin involvement including 8 patients with erythema chronicum migrans (ECM) and 3 patients with acrodermatitis chronica atrophicans (ACA). Two of the patients had unspecific general symptoms and in 5 patients the type of involvement remained unknown. The serology was considered to be falsely positive in 2 patients with tuberculous meningitis, in one with syphilis and in another with recurrent fever.

Isotype distribution and bactericidal activity of antibodies after immunization with Haemophilus influenzae type b vaccines at 18-24 months of age

The serum antibody response to Haemophilus influenzae type b capsular polysaccharide or its protein conjugate vaccine (PRP and PRP-D, respectively) was studied in 28 children initially immunized at the age of 24 mo with either vaccine and in 10 children immunized for the third time with PRP-D at the age of 18 mo. The methods used were isotype-resolving enzyme immunoassay, Farr-type radioimmunoassay, and the in vitro bactericidal activity (BCA) test. Immunization with PRP evoked a higher proportion of IgA antibodies than did either the first or third dose of PRP-D, whereas the latter vaccine evoked a somewhat higher IgG response, but the differences were not statistically significant. In all groups the IgG antibody responses were predominantly IgG1, with the mean proportions being 82.2%, 84.2%, and 65.9% in the PRP, first-dose PRP-D, and third-dose PRP-D groups, respectively. Postimmunization antibodies were functionally active in the BCA test.

Human antibody responses to two conjugate vaccines of Haemophilus influenzae type B saccharides and diphtheria toxin

Antigenicity of two Haemophilus influenzae type b (Hib) conjugate vaccines was studied by immunizing adults and 2-year-old children. Both vaccines induced strong anti-Hib responses and strong antibody responses to diphtheria toxin (DT), the protein part of the conjugate. The adults' responses were stronger than the children's. A conjugate of Hib oligosaccharide and mutant diphtheria toxin (HbOC) emerged as slightly superior to a conjugate of Hib polysaccharide and diphtheria toxoid (PRP-D). HbOC induced somewhat higher total anti-Hib responses and significantly higher IgG1 anti-Hib responses than PRP-D. IgG1 and IgG2 were the main IgG subclasses of the anti-Hib antibodies, whereas IgG1 and IgG4 were the main subclasses of the anti-DT antibodies. Within this main rule, the ratio IgG1/IgG2 of anti-Hib antibodies varied between individuals. The average ratio was higher than five in children but approximately one in adults. It was lower in adult recipients of the polysaccharide conjugate (0.69) than in adult recipients of the oligosaccharide conjugate (1.55). A large interindividual variation was observed in concentrations of IgG2 of Hib specificity, perhaps reflecting a small number of IgG2-committed B-cell clones participating in the response.

Intrathecal humoral immunologic response in neurologically symptomatic and asymptomatic patients with human immunodeficiency virus infection

We analyzed the intrathecal humoral immunologic response in 42 human immunodeficiency virus (HIV)-infected patients. Eighteen patients had clinical neurologic abnormalities, while the remaining 24 patients were neurologically symptom-free. Nine of the neurologically symptomatic patients at early infection had slight neurologic dysfunction; in nine other subjects at late infection, the neurologic impairment was moderate or severe. When compared with symptom-free patients, neurologically symptomatic patients had increased intra-blood-brain barrier (BBB) HIV-specific IgG (p less than 0.001) and total IgG synthesis (p less than 0.01) with oligoclonal bands (OCBs) in the CSF and/or serum (11/18 versus 3/24). At early stages of the infection, neurologically symptomatic patients showed increased total intrathecal IgG synthesis (9/9) coincident with OCBs in the CSF and serum (7/9) and slight mononuclear pleocytosis (7/9), but less frequent HIV-specific IgG production within the CNS (6/9). In advanced infection, the number of neurologically symptomatic patients with intrathecal HIV-specific IgG synthesis (8/9) was higher, while the number of those with increased total intra-BBB IgG synthesis (5/9; p less than 0.01), OCBs (4/9), and increased CSF leukocyte count (1/9; p less than 0.001) was lower than at early infection. Our data suggest humoral intra-BBB immunoactivation at early stages of HIV infection followed by declining B cell response within the CNS at advanced infection.

Oligoclonal immunoglobulin bands in cerebrospinal fluid of patients with Alzheimer's disease and vascular dementia

We examined serum and cerebrospinal fluid (CSF) of 16 patients with Alzheimer's disease (AD), 28 patients with vascular dementia (VD), their age-matched controls and multiple sclerosis (MS) patients in order to evaluate the humoral immune response within the central nervous system both quantitatively and qualitatively. Intra-blood-brain barrier (BBB) protein synthesis was calculated by CSF IgG index. The presence of oligoclonal banding (OCB) was investigated with agarose isoelectric focusing (IEF) followed by immunoblotting with antihuman IgG. No patient with AD and only 4 patients with VD had slightly elevated IgG indexes, and no statistically significant differences in the indexes were found between the two groups. No bands were found in the CSF of AD patients but 3 VD patients had OCB in both serum and CSF. One VD patient had bands in serum but no bands in CSF. No kappa or lambda free light chains were found in those demented patients with demonstrable bands in the CSF and serum. No OCB were found in control sera and CSF. For comparison, the majority of patients with MS had OCB in CSF. Thus, no consistent increase of intrathecal protein synthesis was found in patients with AD and VD. Methodological differences explain at least part of the conflicting results published earlier.

Recent rubella virus infection indicated by a low avidity of specific IgG

Rubella-specific IgG in acute-phase sera produces a characteristically altered zone termed "soft hemolysis" in the radial hemolysis test. Here, the soft hemolysis was shown to be a product of the purified IgG1 subclass isolated from acute-phase sera. In contrast, ordinary hemolysis was produced by IgG1 isolated from sera of previous rubella immunity, indicating that the subclass composition of IgG was not involved in the mechanism of soft hemolysis. A novel type of solid-phase immunoassay was developed for the avidity of virus-specific IgG. Acute-phase IgG (with soft hemolysis) was dissociated from rubella antigen in an enzyme immunoassay (EIA) test by hydrogen-bond disrupting agents under conditions where IgG of previous immunity (showing ordinary hemolysis) remained mostly bound. These data suggest that the mechanism of soft hemolysis is the avidity of rubella-specific IgG. The new quantitative avidity EIA was tested with sera taken from 169 subjects. Recent infection could be shown from sera taken weeks or months after primary rubella.

Serum IgG subclass levels in paediatric clinic patients with variable degrees of IgA deficiency

We measured IgG subclass levels by radial immunodiffusion with polyclonal antisera in 60 patients with IgA deficiency. The low IgA levels were measured by a sensitive and specific enzymoimmunometric method. None of the patients had complete deficiency of IgG2, but 4 patients had serum levels of IgG2 and 4 of IgG3 below the range for controls. Elevated levels of IgG1 were found in patients with juvenile rheumatoid arthritis and coeliac disease. None of the patients with coeliac disease or juvenile rheumatoid arthritis had low IgG2 or IgG3 levels. The levels of IgG4 were highly variable but patients with coeliac disease had particularly high values. The severity of IgA deficiency did not correlate with the level of serum IgG2.

ELISA measurement of IgG subclass production in culture supernatants using monoclonal antibodies

Specific and sensitive ELISA to quantitate the human IgG subclasses in cell culture supernatants are described. These assays detect a minimum of 5 ng/ml IgG1, 90 ng/ml IgG2, 8 ng/ml IgG3 and 8 ng/ml IgG4 and can generally measure IgG subclasses in lymphocyte cultures containing a minimum of 200 ng/ml of total IgG. The isotype specificity of these ELISA is demonstrated and each individual ELISA shown to react with a number of paraproteins of the relevant subclass independently of their light chain type or their (major Caucasian) allotype. These assays have been used to determine the IgG subclass response of normal human lymphocytes to pokeweed mitogen in vitro.

Isotype concentrations of human antibodies to Haemophilus influenzae type b polysaccharide (Hib) in young adults immunized with the polysaccharide as such or conjugated to a protein (diphtheria toxoid)

Antibody responses of young adults to Haemophilus influenzae type b polysaccharide (Hib) or its protein conjugate were studied with special attention to the isotype composition of the antibodies. Three conclusions of interest can be made: 1) Immunoglobulin G (IgG) antibodies in polysaccharide-immunized volunteers displayed the subclass pattern previously found in antibodies to meningococcal type A polysaccharide. IgG1 was the predominant subclass in IgG antibodies of some individuals, IgG2 in others. Still others had the two subclasses in varying but more even proportions. 2) The conjugate vaccine induced a geometric mean response 2 to 3 times higher and an IgG response 4 times higher to Hib than the polysaccharide vaccine. 3) Anti-Hib antibodies induced by the conjugate vaccine still had essentially the same IgG subclass composition as anti-Hib antibodies induced by the polysaccharide. This composition was strikingly different from the composition of the anti-diphtheria toxoid response induced by the same conjugate vaccine.