RECURSOS, SERVICIOS Y PRESTACIONES
4.3.3. Las funciones del Trabajo Social en la violencia de género
7.4.1. EndoCAb specific IgM & IgG antibody measurements.
Serum IgM and IgG EndoCAb levels were assayed by means of the previously described ELISA assay (Chapter 2.0.)
7.4.2. S. typhi H-antigen specific IgM antibody measurements.
Determination of the response of H-antigen specific antibodies was performed using a tube agglutination technique (Murex Diagnostics Ltd, Dartford, England). This serological test is based on the fact that antibodies in serum, produced in response to exposure to bacterial antigens, will agglutinate bacterial suspensions which carry homologous antigens.
A series of serum dilutions were made in 0.25% phenol saline, with final serum concentrations ranging, in doubling dilutions, from 1:20 to 1:1280. One measured drop of S. typhi suspension was added to each serum dilution, mixed and incubated at 50°C
for two hours before reading. H-agglutination was titred by identifying the highest dilution displaying the characteristic flocular appearance.
A dilution series of S. typhi-H agglutinating serum was used as a positive control.
7.4.3. Serum total IgM measurements.
Serum total IgM measurements were made by radial immuno diffusion. Control serum or sample serum (5|xl) was applied to individual wells of NOR-Partigen-IgM (Behring Diagnostics, Hounslow, UK) plates containing monospecific antiserum to human IgM. After expiration of a diffusion period of five days at room temperature, the diameters of the precipitates were measured. The control serum values were plotted logarithmically as a standard curve from which the serum sample IgM values were calculated.
7.5.
RESULTS.
7.5.1. Clinical effects of monovalent S. typhi vaccination.
All subjects experienced a mild flu-like symptoms for 24-48 hours with localised injection site inflammation.
7.5.2. Immune responses to monovalent S. typhi vaccination.
The IgM EndoCAb levels showed an increase in levels in 5 of the 8 subjects (mean = 70%: range = 49 - 85% ) with 3 subjects failing to mount a response to the core epitopes of the endotoxin. Four of the eight subjects demonstrated a marked rise in serum IgG EndoCAb in response to inoculation with the vaccine by day 19 (mean elevation in levels = 68%; range 39-112%). Four of the subjects failed to demonstrate an elevation. Individual responses are shown in Fig 7.1. with all time point readings tabulated in
appendix 7.1.
All 8 subjects demonstrated a satisfactory response to the S. typhi specific H-antigen allowing detection at a dilution of 1:640 at 10 days post vaccination.
When considering the generalised total IgM response to the vaccine, 6 of the 8 subjects showed an elevation in total IgM (mean = 157%: range = 36-540% ). Of the EndoCAb non-responders 2 of the 3 demonstrated no elevation in total serum IgM levels thus indicating a poor generalised response to the vaccine despite good specific S. typhi
protection. One subject demonstrated elevation in total serum IgM and a good response to the H-antigen of S. typhi but a poor response to the endotoxin core indicating that the antibodies generated were not directed against the core epitopes.
Figure 7.1 The e ffe c t o f m o n o v a le n t ty p h o id v a c cin e on to ta l se ru m Ig M a n d E ndoC A b specific IgM and IgG levels.
Responders Non-responders 250 g 200- Q 1 0 0 - T--- r Baseline M aximum Post-Vaccine 250 2 0 0- 1 5 0 - 100- 5 0 - Baseline M axim um Post-V accine P X5 <
y
T3 [§ % y 4 0 0 - 4 0 0 - 3 0 0 - 3 0 0 - 200- 200- 100- 100- --- 0- 0- Baseline Maximum Post-Vaccine Baseline M axim um Post-V accine 15 10 5 0 Baseline M aximum Post-Vaccine Baseline M axim um Post-V accine 1 3 97.6.
DISCUSSION.
In the EndoCAb responders group (n=5) the mean rise in IgM EndoCAb was of the order of 70% and IgG EndoCAb of 75%, while the rise in IgM EndoCAb was only 16% and IgG EndoCAb only 1 % in the non-responders. The mean rise in total serum IgM in the group of responders (n=6) was 157% with no rise in the non-responders.
Of interest was the fact that the two subjects with the highest baseline IgG EndoCAb levels , thereby reflecting chronic immunity, were from the Indian subcontinent, which may reflect a genetic or dietary influence on the immune system.
All subjects undergoing vaccination experienced flu-like symptoms that may not be acceptable in patients about to undergo cardiac surgery. In addition to this most of the non-responders' have low levels of EndoCAb at baseline. This may indicate that the reason behind their low levels may reflect a chronic non-responsiveness to an endotoxin challenge. As this is the group that are considered most 'at-risk' based on their pre operative EndoCAb levels, this may bode badly for the therapeutic concept of active immunisation to elevate EndoCAb levels in those with low pre-operative levels. Further investigation is required into this area.
It is well known that not all people will respond to vaccines in a similar manner (Rao 1991), the problem comes in determining which people will respond and how vigorous that response will be. Determination of the EndoCAb status of the patient is easily performed at the surgical outpatient appointment when the need for surgery is considered. In most cases this will still give enough time for those with low levels to be administered the vaccine as an outpatient the following week. A blood sample can be taken either at the hospital outpatient clinic or at a local health facility the week prior to the given date for surgery and the response to the vaccine determined. If the response has been inadequate the patient may then be considered for pre-operative passive immunotherapy (see