Magnus Roberg

The outer surface proteins of Lyme disease borrelia spirochetes stimulate T cells to secrete interferon-gamma (IFN-γ) : diagnostic and pathogenic implications

Late stages of borrelia Lyme disease infections may be difficult to diagnose because of unspecific symptoms and unreliable laboratory tests, being too unspecific or insensitive. The T cell immune response was thus evaluated in these patients by using a sensitive ELISPOT T cell assay that detects the secretion of IFN‐γ, i.e. a T helper 1 (Th1) response on the single‐cell level. Three subcellular fractions of the Lyme borreliosis strain Borrelia afzelii were used for antigenic stimulation. The outer surface protein (Osp) fraction elicited the strongest response, discriminating between borrelia infections (n= 15) compared with other neurological diseases (n= 10) and normal controls (n= 12) (P= 0.0001). The more heterogeneous sonicated borrelia fraction also elicited a strong response, however, also in some of the controls. The flagellin fraction did not have a similar T cell‐stimulating effect. When looking at subgroups of borrelia infections, central nervous system (CNS) infections (n= 7) revealed a lower T cell response in blood (P= 0.0128) compared with other borrelia manifestations (n= 8). Cerebrospinal fluid (CSF) lymphocytes were available from three patients with CNS borreliosis, and all showed a compartmentalization with higher responses to the Osp fraction in CSF compared with blood, also in the two patients without any intrathecal‐specific antibody synthesis. The ELISPOT method is feasible for detecting a specific IFN‐γ T cell response in borrelia infections. This Th1 response may well be of pathogenic relevance.

Asymptomatic Borrelia-seropositive individuals display the same incidence of Borrelia-specific interferon-gamma (IFN-γ)-secreting cells in blood as patients with clinical Borrelia infection

Lyme disease is a complex disorder that sometimes becomes chronic. There are contradictory reports of experimental Borrelia infections regarding which type of T cell cytokine responses, i.e. Th1 or Th2, are needed to eradicate the Borrelia spirochaetes. In human borreliosis a predominance of Borrelia‐specific Th1‐like responses has been shown. In this study, spontaneous, as well as Borrelia‐specific, secretion of IFN‐γ (Th1) and IL‐4 (Th2) in Borrelia‐seropositive healthy asymptomatic individuals (n = 17) was investigated in peripheral blood by a sensitive ELISPOT assay, and compared with previously reported responses in patients with clinical Borrelia infection (n = 25). The seropositive asymptomatic individuals displayed the same predominance of Borrelia‐specific IFN‐γ‐secreting cells as the patients with clinical Borrelia infection. Interestingly, the proportion of spontaneously IL‐4‐secreting cells, reflecting the unstimulated in vivo secretion, was lower in the seropositive asymptomatic individuals compared with patients with chronic Borrelia infections (n = 13, P = 0.02), whereas no such difference was found compared with subacute Borrelia infections (n = 12). These findings indicate that IFN‐γ secretion alone is not sufficient to eliminate Borrelia spirochaetes in humans, although IFN‐γ may still have a beneficial role in borreliosis acting in concert with other mechanisms.

Hepatocyte Growth Factor Levels in Cerebrospinal Fluid: A Comparison between Acute Bacterial and Nonbacterial Meningitis

The organotrophic functions of the hepatocyte growth factor (HGF) have been the subject of several studies. In the more recent studies, this function has been reported in the brain. In the present study, we have measured the levels of HGF in cerebrospinal fluid (CSF) and sera from 78 patients divided into 6 different groups according to central nervous system (CNS) infection and control. Quantitative measurements of HGF in the CSF and serum were performed by an enzyme-linked immunosorbent assay. Elevated values of CSF HGF were found in the patients with acute bacterial/probable bacterial meningitis (P<.001), compared with nonbacterial CNS infections and facial palsy, as well as with a control group without signs of CNS involvement. The values of CSF HGF were not correlated to blood-brain-barrier disruption in the groups. These observations might indicate an intrathecal production of HGF in acute bacterial/probable bacterial meningitis.

Acute “idiopathic” peripheral facial palsy: Clinical, serological, and cerebrospinal fluid findings and effects of corticosteroids

INTRODUCTION The causes for peripheral facial palsy remain obscure in many patients. Evidence exists suggesting viruses, especially those belonging to the herpesvirus group, may be causative. This study was developed to evaluate this theory. METHODS One hundred forty-seven patients with acute peripheral facial palsy of primarily unknown origin were studied. All were examined within 1 week of onset. Subsequent follow-up was undertaken until the palsy had recovered or become static. Paried cerebral spinal fluid and serum samples were obtained for serological evaluation to detect herpes simplex, varicella zoster, cytomegalovirus, measles, mumps, rubella, tick-borne encephalitis, adenovirus, Epstein-Barr virus, and human immunodeficiency virus, as well as the antibodies to Borrelia burgdorferi. RESULTS Elevated antibiotic titers to Borrelia burgdorferi were observed in 11% of patients, whereas 9% of patients demonstrated elevated viral titers. Antibody pattern consistent with Epstein-Barr virus reactivation was present in 13%. A total of 67% were classified as idiopathic. CONCLUSION Patients with reactivated Epstein-Barr virus were characterized by having a higher incidence of auricular pain and displayed diabetes mellitus in a higher frequency than in other groups. In the Borrelia group, neck/back pain was more common. Healing was less favorable in the Borrelia group despite an equal rate of palsy at onset and adequate antibiotic treatment. Corticosteroid treatment used in 44% of the patients did not significantly improve the functional outcome.

Antibodies and T-Cell Reactivity to Borrelia Burgdorferi in an Asymptomatic Population: A Study of Healthy Blood Donors in an Inland Town District in the South-East of Sweden

To address the issue of whether Borrelia infection can be asymptomatic, blood donors with no history of borreliosis (n = 408) were screened for antibodies against Borrelia burgdorferi. Seropositive individuals (n = 17) were further investigated with respect to Borrelia-specific T-cell reactivity, using an interferon-gamma ELISPOT assay. Anti-Borrelia antibodies as well as Borrelia-specific T-cell responses were evident in 9 asymptomatic donors, strongly supporting a current or previous asymptomatic Borrelia infection.To address the issue of whether Borrelia infection can be asymptomatic, blood donors with no history of borreliosis (n = 408) were screened for antibodies against Borrelia burgdorferi. Seropositive individuals (n =17) were further investigated with respect to Borrelia-specific T-cell reactivity, using an interferon-γ ELISPOT assay. Anti-Borrelia antibodies as well as Borrelia-specific T-cell responses were evident in 9 asymptomatic donors, strongly supporting a current or previous asymptomatic Borrelia infection.

Intrathecal production of specific IgA antibodies in CNS infections

Cerebrospinal fluid (CSF) and serum from subjects with herpes simplex encephalitis, herpes zoster, mumps meningitis and neuroborreliosis were analysed for the presence of immunoglobulin A (IgA) and G (IgG) antibodies to the corresponding four antigens. Specific intrathecal IgA antibody synthesis as manifested by an elevated index was a frequent finding. Higher IgA index values than the corresponding IgG was seen in one third of the samples from subjects with herpes simplex encephalitis and herpes zoster. Correlation between specific IgG and IgA index was most pronounced for varicella-zoster virus (r =0.66,P < 0.001). In subjects with mumps meningitis a strong intrathecal IgA and IgG antibody response toBorrelia burgdorferi was demonstrated. Specific herpes simplex and varicella-zoster virus IgA was not found to contain secretory component, thus contradicting an active secretion into the CNS compartment. In conclusion, our data indicate that specific IgA is intrathecally produced in herpes simplex encephalitis, herpes zoster and mumps meningitis but is a rare finding in neuroborreliosis.

Long-term Findings in Patients with Facial Palsy and Antibodies against Borrelia burgdorferi

Little is known about the long-term effects of Borrelia burgdorferi (Bb) infection in untreated patients with peripheral facial palsy. We investigated 12 patients with elevated serum Bb antibody levels, with a median follow-up time of 11 years, during which 3 of the 12 still exhibited intrathecal antibody production of antibodies against Bb flagellar antigen, and 2 of the 3 had normal serum Bb antibodies. Four of the 12 had elevated serum antibody titres at the late follow-up examination. Arthralgia, reported by 7 patients, was the single most common complaint. Four patients showed extensive oculomotor disturbances, which were not correlated to antibody titres or intrathecal antibody synthesis. In 1 of the patients with intrathecal Bb antibody production, most symptoms were eradicated by antibiotic treatment 6 years after the initial infection. We conclude that even several years after a Bb infection, intrathecal Bb antibody production can still occur in serum Bb IgG antibody negative patients with a history of facial palsy.

Lower Values for Immunoglobulin M in Cerebrospinal Fluid When Sampled with an Atraumatic Sprotte Needle Compared with Conventional Lumbar Puncture

Immunoglobulin M (IgM) has a very low concentration in cerebrospinal fluid (CSF) compared with serum, and therefore determinations of IgM in CSF are highly sensitive to pre-analytical errors caused by contamination with serum or interstitial fluid. Capillary attraction causes a thin layer of liquid containing serum proteins to be formed inside a conventional (Quincke) needle during penetration of tissue. To investigate this source of pre-analytical error, 35 patients had lumbar punctures using a 22 G atraumatic (Sprotte) or 25 G conventional (Quincke) needle according to a randomized scheme, and the IgM concentrations in CSF and serum were determined. The CSF IgM concentrations for samples taken with a Sprotte needle were significantly lower than those taken with a Quincke needle (P < 0·05), whereas the corresponding serum IgM concentrations and CSF erythrocyte counts did not differ significantly. The difference indicates that CSF IgM concentrations determined after conventional sampling may be falsely increased by contamination. We conclude that IgM concentrations in CSF samples taken with the atraumatic technique are more accurate, and recommend the use of this technique when CSF IgM is to be determined.

Determination of Total and Herpes Simplex Virus Specific Monomeric and Dimeric IgA in Serum and Cerebrospinal Fluid by Ultracentrifugation

An improved method is described for differentiating between monomeric and dimeric total and herpes simplex virus (HSV) specific IgA by ultracentrifugation in sucrose gradient, using recovery and quantitative analysis of the fractions obtained. Calculation of monomeric and dimeric IgA was based on IgG as an internal standard. Intrathecally produced monomeric and dimeric IgA were judged by calculating IgA indices for each form. A new type of formula indicating relative over-production of dimeric compared with monomeric IgA (IgA dimeric-monomeric index) is suggested. The method was applied to serum and cerebrospinal fluid (CSF) from three patients with HSV encephalitis. The index for monomeric as well as dimeric IgA was high during the acute phase of the disease, indicating intrathecal synthesis of both molecular forms. One year after onset, there was no detectable HSV-specific IgA in CSF: Both molecular forms, however, remained in serum. The amount of dimeric compared with monomeric IgA was high during the acute phase, and subsequently decreased after successful treatment. A new finding was the detection of HSV-specific IgA heavier than dimeric IgA in serum one year after onset of the disease. These components may be tetrameric IgA, or immune complexes containing IgA.