Volume: 4 Table of Contents: I. LDF: Notes from the IXth Annual LDF Scientific Conference (Part 1 of 3) II. About The LymeNet Newsletter Newsletter: *********************************************************************** * The National Lyme Disease Network * * LymeNet Newsletter * *********************************************************************** IDX# Volume 4 - Number 08 - 6/14/96 IDX# INDEX IDX# IDX# I. LDF: Notes from the IXth Annual LDF Scientific Conference IDX# (Part 1 of 3) IDX# II. About The LymeNet Newsletter IDX# I. LDF: Notes from the IXth Annual LDF Scientific Conference (Part 1 of 3) ----------------------------------------------------------------------- Sender: Lloyd E. Miller, DVM <[email protected]> Notes from the Ninth Annual Scientific Conference Lyme Disease Foundation -- April 19-20, 1996 -- Westin Copley Plaza Hotel, Boston, Massachusetts, USA Prepared by Lloyd E. Miller, DVM ----------------------------------------------------------------------- Every effort has been made to report the speaker's statements and to report suggested drug doses accurately. However, typos do occur and as information gets passed around or edited mistakes can occur. The reader is cautioned to not take any medication before checking the accuracy of name and dose recommendations with the speaker. Selected abstract statements have been included in the notes. The notes themselves are from statements made by the speakers. My editorial comments will be found in brackets like this [COMMENT]. Full abstracts are available electronically from the Lyme/Other Zoonoses section in the Public Health Forum on Compuserve. ------------------------------------------------------------------ *** Protective and Disease-modulating Antibody-mediated Immunity to Borrelia burgdorferi Antigens Expressed in vivo. - Stephen W. Barthold, Ph.D., D.V.M. FROM THE ABSTRACT: * We have utilized a well-defined mouse model of Lyme disease, in which mice infected by syringe of tick develop heart and joint disease that undergo spontaneous resolution and episodic recurrence over the course of persistent infection. * Spirochetes appear to persist extracellularly within collagenous connective tissue, particularly the skin. * Spirochetes entering the host do not express OspA, and are therefore not vulnerable to OspA immunity. During infection, other proteins are expressed that are probably required for tissue invasion. * Host humoral, but not cellular, responses directed against in vivo-expressed proteins have varying degrees of protective activity and are also involved in resolution (and recurrence) of disease. FROM THE NOTES: * Basis for first statement in above abstract excerpt: Bb which are in the skin chronically do not produce an inflammatory response. They can be cultured and produce disease when injected into another mouse. * Persistent infection has been seen in most animals tested. * Lyme carditis occurs spontaneously and clears without treatment and then periodically recurs in humans. The same occurs in laboratory mice. * In mice with arthritis, spirochetes can be found. When the arthritis clears no spirochetes can be found. When the arthritis recurs spirochetes can again be found. Lacking an immune response the host can not clear spirochetes and becomes severely arthritic. Bb react differently in different tissues in the same host. * Patients do not produce antibodies to OspA. Host adapted spirochetes do not express OspA and therefore OspA vaccine will not protect. [ See notes further on for differing opinions on this statement.] * Bb in feeding tick stops production of OspA and increases production of OspC. * OspC can immunize against challenge but has no effect against existing infection. * Serum from infected mice would protect naive mice from infection by injection of Bb but not from infection by tick bite. * Immune serum injected into previously infected mice did not result in a decrease of spirochetes in the blood. They were eliminated from the joints but not the heart. * Immune serum injected soon after allowing tick to feed in naive mice did not protect. * Bb express different antigens in vivo than in vitro. There are probably antigens expressed in vivo that could be important in vaccination protection. * Transfer of T-lymphocytes from infected mice to naive mice did not protect the naive mice from infection. Thus the third statement in the abstract excerpt above. * Speculated that Bb may shut down antigen production when it enters the host and thus resists detection by the hosts immune system. *** Hamster Model of Lyme Borreliosis - Ronald F. Schell, Ph.D. [ COMMENT: This presentation was a continuation of research reported at this same conference in 1994 and 1995 where it was reported that hamsters challenged with homologous stains of Bb developed severe arthritis post vaccination and prior to the development of immunity. It was also reported that when the protective titer waned arthritis would also develop on challenge. This report shows that Bb specific T-lymphocytes were responsible for the development of the arthritis. The importance of this is related to the development of safe and effective vaccination and in the development of medications that may prevent or treat the arthritis caused by Bb. ] FROM THE ABSTRACT: * When vaccinated hamsters are depleted of CD4+ T lymphocytes by administration of monoclonal antibody GK1.5 and challenged, they failed to develop severe destructive arthritis. * Similarly, nonvaccinated hamsters with or without depletion of CD4 T-lymphocytes failed to develop severe destructive arthritis. * Our results also suggest that as more protective antigens are added to develop a comprehensive Lyme vaccine, the ability of these proteins to induce or elicit adverse effects may increase. FROM THE NOTES: * He expressed surprise at the extent of the severity of arthritis that CD4 lymphocytes influence. * CD8 lymphocytes also influenced the arthritis. *** Chronic Lyme Disease in the Rhesus Monkey - Mario Philipp, Ph.D. FROM THE ABSTRACT: * Two mechanisms that members of the genus Borrelia use to avoid the host's immune response are antigenic variation and residence in tissues into which antibodies and lymphocytes have poor access. FROM THE NOTES: * Possible mechanisms of persistence of Bb and disease: 1. Poorly immunogenic species - not cleared by the immune system. 2. Antigenic variability through various genetic mechanisms - expressing various antigens over time staying one step ahead of the immune system. 3. Intracellular location - avoids immune system and many antibiotics. 4. Access to niches - privileged sites - clear precedence = syphilis in the brain. CNS niche is important. 5. Nucleic acid persistence - blebs continue to produce protein but technically speaking no live organisms are present. * OspA does have significance in mammalian hosts - most patients on Shelter Island with arthritis have strong expression of both OspA and OspB. [ This information appears to differ from Barthold's ]. *** Correlation of Severity of Arthritis with Level of Persistence of Spirochetes in Murine Lyme Disease - Janis Weis, Ph.D. FROM THE ABSTRACT: * Findings support the model in which the severity of pathology is directly related to level of persisting spirochetes in tissues. FROM THE NOTES: * C3H mice develop more severe disease of the joints and heart than BALB/c mice which can be overcome by injecting more Bb into BALB/c mice. * Nitrous oxide (NO) is found in high levels in inflammed tissues. NO has antimicrobial properties. NO is toxic to Bb in vitro. Is it involved in host defense against Bb? BALB/c mice produce more NO. When NO production was decreased in both species of mice no attenuation of spirochete infection was found. Conclusion NO is not involved in host defenses against Bb in mice and probably other species. * Nitrous oxide is an important defense in intracellular infection. Evidence that it is not involved in defenses against Bb argues that Bb may not be an intracellular pathogen. [ Several speakers feel this may be true - others are not yet convinced ]. * Study of infection in pregnant mice: 1. Recent (near the time of mating) infection produced 12% fetal deaths. Bb was found in the uterus of mother but not in the placenta. 2. Chronic infection (more than three weeks prior to gestation) resulted in fewer fetal deaths and no Bb were found in the uterus. 3. Bb was rare in fetal tissue. Fetal deaths are associated with the mother not the fetus. 4. Therefore effect on pregnancy low. *** Effects of Borrelia burgdorferi on Human B- and T-Cells - David W. Dorward, Ph.D. FROM THE ABSTRACT: * Since discovering late in 1994 that virulent B. burgdorferi can target, invade, and kill primary and cultured human T-and B-lymphocytes, we have investigated the mechanics of such interactions to help understand the role they may play in the onset, development, and persistence of Lyme disease. * In vitro co-incubations of low (<8) or high (>30) passage spirochetes with SKW 6.4 B-cells or H9 T-cells were used as a model to quantitate and study the consequences of interactions on cell structure and viability. * Attachment and invasion were detectable in all mixtures examined. By 30 minutes, numerous spirochetes were observed either extending or detached from host cells, yet surrounded by a layer(s) of membrane(s) and cytoplasm, apparently derived from the host cells. Prior to these studies invasion and killing of human lymphocytes was unrecognized among bacterial pathogens. * These results indicate that attachment and invasion of human lymphocytes by Lyme disease spirochetes is active and rapid. * These findings also raise the possibility that the spirochetes could acquire lymphocytic membranes and surface markers upon or even prior to transmission by infected ticks, which would be expected to have profound effects on recognition by the immune system. FROM THE NOTES: * Dramatic photographs taken though the electron microscope showed spirochetes being engulfed and extruded from the lymphocytes simultaneously. * The spirochete coating itself with lymphocyte membrane inhibits the ability of antibodies to recognize and kill them. * The process allows avoidance of phagosomal fusion of normal macrophages. [ COMMENT: This presentation was really fascinating and very thought provoking. If this process occurs in vivo the implications are immense and provides a very plausible explanation on how Bb avoids detection and elimination. Just think what this means if it is a continuous process not just limited to the time of tick attachment. Could it explain the resistance to antibiotic elimination too? Is the spirochete creating its own privileged site? Gaining an understanding of this process may provide important clues for new preventive and treatment strategies. This was one of the most significant presentations. ] *** Acquisition and Induction of Enzymes which Degrade the Extracellular Matrix by Borrelia burgdorferi and other Borrelia Species. - Mark Klempner, M.D. FROM THE ABSTRACT: * For virtually all bacteria which disseminate from a skin or soft tissue inoculation site produce bacterial proteases, which digest extracellular matrix proteins, facilitate spreading in the skin and subsequent invasion into the lymphatic or vascular circulations. * We have found that B. burgdorferi lacks these proteases but is able to spread from its inoculation site in the skin. Instead, B. burgdorferi has evolved a mechanism for accomplishing this step in pathogenesis by utilizing human proteases which are generated at the inoculation site and become bound to the bacterial surface. * We have also discovered that B. burgdorferi induces the release of enzymes that degrade the extracellular matrix from cells in the skin and the central nervous system. * Utilization of host proteases instead of proteases of microbial origin could explain why the immune response to B. burgdorferi infection is blunted. These observations represent a new mechanism for bacterial virulence which may identify new targets for prevention, diagnosis, and treatment of Lyme disease. [ COMMENT: The abstract is very complete. No notes were necessary. This presentation also provides significant information on how Bb can gain entrance to the body. Such host adaption as reported here doesn't happen overnight. Is this further evidence that Bb is an ancient organism ?] *** Why is Chronic Lyme Borreliosis Chronic? - Elizabeth Aberer, M.D. FROM THE ABSTRACT: * Recently, it was shown that the most important cell for antigen presentation, the epidermal Langerhans cell (LC), is heavily damaged in erythema migrans (EM). * In this study, the most prominent immunohistochemical changes were seen on the epidermal dendritic cell population. Our data suggest that MHC class II molecules are strongly down regulated on LC not only in the early but also in the late stage skin manifestation of LB. FROM THE NOTES: * The numbers of LC cells in EM was reported to be normal and even increased in ACA (acrodermatitis chronica migrans) but their function was adversely affected. [ COMMENT: This provides yet another possible mechanism for the survival (persistence) of Bb. ] *** Anti-Borrelial Activity of Serum From Patients with Late Lyme Disease - Charles Pavia, Ph.D. FROM THE ABSTRACT: * Separate groups of mice (C3H strain) received intraperitoneal injections of 0.5 ml of high titer serum from human patients with (i) early (erythema migrans) or (ii) late Lyme disease (arthritis). Some of these patients were culture-positive; all were seropositive and antibiotic-free. * Twenty-four hours after passive serum transfer, all of the mice, including matched controls given the appropriate normal sera lacking borrelia antibodies, were challenged intradermally with 100,000 organisms of two New York isolates (B31, P103) or of a California strain (CA-287) * Seven to 10 days after challenge, the mice were sacrificed and cultures for the urinary bladder and peripheral blood were established in BSK media. Late Lyme sera fully protected the mice against Borrelia challenge infection with all three isolates (based on negative cultures of urinary bladder and blood) but, in marked contrast, early stage Lyme sera were generally ineffective in preventing infection. * Immunoblot analysis revealed that the protective properties of late Lyme sera were associated with a multi-protein antibody response. This included strong reactivity with the outer surface proteins A (31kDa) and B (34 kDa), which was lacking in sera from those with early stage disease. * These findings show that patients with untreated Lyme disease of long duration can develop a potent anti-borrelial humoral immune response which can be protective against infection and possibly reinfection. [ This statement appears to be contrary to what has been reported by others. ] FROM THE NOTES: * Bb grow at 32 -34 degrees C - cooler temperatures - maybe this helps explain its predilection for skin. * In patients with EM seropositivity increases with time. Up to 80% of patients have a positive test by one month - depending on the tests used. [ This also differs from seropositivity rates reported by others. ] * With early Lyme - will never get all patients to be seropositive for diagnostic purposes. * The number of Western blot bands reacting increases with time in *untreated* patients. * Note: the sera that protected the mice from challenge was unprotective in the patient as evidenced by the positive cultures in some of the patients. *** Western Immunoblot for Lyme Disease: Determination of Sensitivity, Specificity and Interpretive Criteria Using Commercially Available Performance Panels - Richard C. Tilton, Ph.D. FROM THE NOTES: * All Western blots are not created equal. * Essentially the CDC criteria and testing is no better than others. There is no gold standard test. * By considering the 83Kda band in early Lyme disease it appears to improve the diagnostic value of the Western blot test. Currently the CDC does not consider this band important in early Lyme disease. * Questioned the appropriateness of accepting Western blot criteria edicts without question - i.e. the CDC criteria. *** Use of PCR Assays to Monitor the Clearance of B. burgdorferi DNA From Blood Following Antibiotic Therapy - Mark Manak, Ph.D. FROM THE ABSTRACT: * A PCR approach was used to monitor the effectiveness of antibiotic therapy on the persistence of B. burgdorferi sequences in the blood of Lyme disease patients. * As few as 3-10 copies of the B. burgdorferi DNA in the sample could be detected. Positive PCR results were obtained mainly with the buffy coat fraction, although occasional plasma fractions were also positive. * Within 1 week of administration of antibiotic treatment 7 of 8 initially PCR positive patients became PCR negative. The remaining patient became PCR negative after 5 weeks of therapy. * Four late stage patients under therapy continued to show sporadic PCR positive results. When an alternative antibiotic was administered in two of these patients, both became PCR negative within one week following the change in therapy. * One patient who had been PCR negative while under therapy, became PCR positive within 2 weeks of cessation of therapy. * These studies demonstrate the usefulness of PCR results in monitoring the effectiveness of antibiotic therapy in Lyme disease patients. [ COMMENT: This was one of the more controversial presentations. The PCR tests were run on the buffy coat (white blood cell) fraction of the blood not on any other fluids or tissues. No correlation was made in the presentation between PCR result and clinical symptoms. There were no controls in this study. It is my understanding that Bb will only be found sporadically in the blood stream. How this phenomenon relates to this study is unclear. In discussion after the presentation I learned that in order to get the first positive PCR in a patient multiple PCR's were necessary. At any one time an infected patient will be PCR negative. During the discussion period it seemed to me the presenter was reluctant to correlate the PCR data with the patient symptom data. Does the sporadically positive PCR tests in the four patients imply persistent infection following therapy. I'm not sure I can agree with the conclusion of this study, at least not until the PCR results are correlated with the clinical responses and not until long term follow up is reported and not without the study of other fluids and tissues in the appropriate circumstance. ] *** PCR in the Diagnosis of Patients with Early and Late Lyme Borreliosis: Comparison of Methods - Bruno L. Schmidt, Ph.D. * This presentation described a nested PCR technique developed for testing urine and made the conclusion that ; In urine samples from patients with Lyme Borreliosis, known to harbour only low numbers of spirochetes (<50/ml), the nested PCR is superior in comparison to other methods. In addition, results indicate that primers are decisive for sensitivity. *** Progress in the Clinical Development of a Lyme Disease Vaccine in the U.S.A. - Francois Meurice, M.D. FROM THE ABSTRACT: * A double blinded, placebo controlled, dose-range study was conducted in 350 healthy adult residents of three New England islands on which LD is highly endemic. An Osp A antibody response was detected in >97% of subjects receiving vaccine. * A second trial addressed the issue of vaccination of subjects previously infected with LD. The safety and reactogenicity profile of the candidate vaccine in this population was similar to the previous observations: all doses were well tolerated, although mild local reactions were common (mostly soreness at the injection site: 40-85%). Transient systemic reactions were reported by <40% of subjects and included headache, fatigue and arthralgia. Adverse events did not increase following subsequent injections. [ COMMENT: This presentation described the complexities of doing vaccine trials in humans. No efficacy results were presented. ] *** Overview of Lyme Disease Vaccine Trials - John M. Zahradnik, M.D. FROM THE NOTES: * Studies in dogs with recombinant OspA (rOspA) vaccine showed it to be very effective in preventing infection shortly following vaccination and one year later. * The amount of antigen in the vaccine correlates with the immune response. The study vaccine contains 30 micrograms of rOspA per dose. Two doses a month apart are given for initial vaccination. * Side effects reported in the study were joint pain, fatigue and headache. There was little difference between the vaccination and placebo group. Repeat vaccination did not produce any other complaints. * This presentation did not provide any information about efficacy in people. These trials are still in progress. * Efficacy trial is being conducted in 14 centers in individuals over 18 years of age in good health and considered to be at high risk in endemic areas or working in endemic areas. * It will be at least two more years before a human vaccine will be available. * Vaccination does not remove the need to take protective measures to prevent tick bite. =====*===== II. ABOUT THE LYMENET NEWSLETTER ----------------------------------- For the most current information on LymeNet subscriptions, contributions, and other sources of information on Lyme disease, please refer to the LymeNet Home Page at: http://www.lymenet.org ----------------------------------------------------------------------- To unsubscribe from the LymeNet newsletter, send a message to: [email protected] On the first line of the message, write: unsub lymenet-l ----------------------------------------------------------------------- LymeNet - The Internet Lyme Disease Information Source ----------------------------------------------------------------------- Editor-in-Chief: Marc C. Gabriel <[email protected]> FAX (for contributions ONLY): 908-789-0028 Contributing Editors: Carl Brenner <[email protected]> John Setel O'Donnell <[email protected]> Frank Demarest <[email protected]> Advisors: Carol-Jane Stolow, Director <[email protected]> William S. Stolow, President <[email protected]> The Lyme Disease Network of New Jersey ----------------------------------------------------------------------- WHEN COMMENTS ARE PRESENTED WITH AN ATTRIBUTION, THEY DO NOT NECESSARILY REPRESENT THE OPINIONS/ANALYSES OF THE EDITORS. ----------------------------------------------------------------------- THIS NEWSLETTER MAY BE REPRODUCED AND/OR POSTED ON BULLETIN BOARDS FREELY AS LONG AS IT IS NOT MODIFIED OR ABRIDGED IN ANY WAY. ----------------------------------------------------------------------- SEND ALL BUG REPORTS TO [email protected] ----------------------------------------------------------------------- |
Home |
Flash Discussion |
Support Groups |
On-Line Library © 1994-1999
The Lyme Disease Network of New Jersey, Inc. |