The pattern of SPIROCHETAL DISEASES antibody production has been outlined under “Immunology,” indicating that treponemal antibody, notably the immobilized, is specific and reflects roughly the immunity status of the patient, whereas reagin is rather an indicator of disease activity. The use of quantitativereagin methods is essential to permit the physician to assess the effect of treatment and compare antibody titers of periodically examined serum specimens in the post-treatment surveillance of the patient.
Three types of treponemal antibody tests are in use:
(1) The treponema immobilization test (TPI) uses live T. pallidum as the antigen, immobilized by antibody in the presence of complement. It is the only test in which the biologic action of serum antibody can be determined directly under the microscope.
(2) The fluorescent treponemal antibody test (FTA) uses killed treponemes as antigen.
The syphilitic serum is bound to the surface of treponemes fixed onto a slide, and the antibody is made visible by use of fluorescein-tagged anti-serum against human globulin. Nonspecific antibodies are removed either by dilution of serum (FTA200 test) or “absorbed” (FTA/ABS test).
(3) The passive treponemal hemagglutination test (TPHA) uses disrupted T. pallidum as an antigen, coated onto tannin-treated sheep erythrocytes which are agglutinated in the presence of specific antibody.
Transient low-titer seroreactivity may, for example, arise from acute bacterial and viral infections, or following vaccinations, e.g., for smallpox. Moreover, both reagin and treponemal serologic tests for syphilis are also reactive by definition in other treponemas-toses (yaws, pinta, and bejel). It should be realized.
However, that syphilis remains the most common cause of reagin seroreactivity and that in screening examinations only one of ten VDRL seroreactive persons may be a problem case requiring confirmation with a specific treponemal test. If TPI or FTA tests, or both, are needed and such tests are not undertaken by a local recognized laboratory, serum specimens can be mailed for examination.
- Among the reagin tests, flocculation reactions, e.g., VDRL, Kline, Eagle, and complement fixation reaction, e.g., Kolmer, are used. In the present article the Venereal Research Laboratory(VDRL) the test is referred to as the prototype of reagin testa its subjected to national proficiency testing within and between laboratories in several countries and is based on the use of antigens referable to International Standard Preparations for the components used.
In quantitative serologic tests a series of a progressively higher dilution of serum is made and each dilution is tested separately. The highest dilution that is reactive represents the laboratory of repute. If there is doubt about the interpretation of serologic tests, consultation should be arranged with a syphilologist. Reagin tests may generally confirm a diagnosis of syphilis’ when a suspected initial lesion is present, although they are usually subordinate to dark-field findings of pallidum, in the early stage. Reagin tests are reactive in all instances of secondary syphilis; they are important in the diagnosis of congenital syphilis, offer a clue in latent syphilis, and have supplementary value in late syphilis. Treponemal antibody tests are essential for diag-nos in patients with repeated low or fluctuating reagin titers, in patients without anamnestic and or clinical evidence, and in acquired and congenital SPIROCHETAL DISEASES, as well as in suspected late manifestations.
Cerebrospinal Fluid Examination. Lumbar puncture can be undertaken at the physician’s office or at a clinic. Examination of the cerebrospinal fluid serves to establish a diagnosis of latent syphilis by the exclusion of asymptomatic neurosyphilis, aids in following the effect of therapy once such diagnosis has been made, and generally assures surveillance of patients in different phases of the disease. Syphilitic meningitis in-creases the permeability of the blood-brain barrier, causing an increase. of lymphocytes, proteins, and in some instances antibody. The first sign of asymptomatic neurosyphilis or meningitis arising from latency is pleocytosis of more than four cells per cubic milliliter, closely followed by an increase in protein to 40 mg. or more (depending on lab-oratory method) and reactive antibody tests. When progressing to parenchymatous neurosyphilis,150 cells or more, marked protein increase (globulin) and strongly reactive antibody tests are encountered. Complement-fixation tests for reagin (Kolmer) and treponemal antibody tests (TPI/ FTA) are most suitable in cerebrospinal fluid examinations. When reactive they are pathogen no monic of neurosyphilis; flocculation tests are sometimes nonreactive when the antibody is present. Successful treatment leads to rapid regression of the. cell count. Normalization of protein requires more time. Reversal of serologic tests may take several years.
Therapy Mahoney and co-workers (1943) introduced penicillin therapy in syphilis, and this drug has replaced previous metal therapy in most countries of the world.SPIROCHETAL DISEASES preparations are more effective antitreponimod agents than the newer penicillins, americium. methicillin. Injection therapy is preferred, mama therapy is not recommended. Uninterrupted-new nematicidal blood-tissue levels are more elective than intermittent penicillinemia, which may be sublethal to T. pallidum and allow growth afermr-giving treponemes, the multiphasic t1 of which is 30 to 35 hours. Long-amionprocsinepesi-selling in oil with aluminiummonosteerniel 19 and benzathine penicillin G TEEM and they’re preferred to short-acting .