Avances

Subjects S/C IMMUNE PARAMETERS CLINICAL SYMPTOMS

l.C K

c+

fluctuated

symptomatic improvement Later succumbed to disease

2. JB

c-

maintained on chemotherapy

3.BM

c-

also IFN-gamma by CDS ÏÏ

symptomatic improvement

4. JBA

c+

disease stabilised

5.JH

c-

tr

41

6.MM

c+

14

injections after first two doses 7JR

c+

symptoms returned 8.SM

c-

14

41

41

9.MC

s-

41

chemotherapy stopped

10. MP

c-

S/C = sputum / culture status for mycobacteria : G- = Was culture+ve before immunotherapy and became culture-ve after immunotherapy S-= Was culture-ve and sputum +ve for mycobacteria before immunotherapy; became sputum-ve after immunotherapy

ft = Increased; ft = Decreased : Different criteria were used for various parameters eg. changes of >4% IFN-y, >8% IL-2 or >1.0% IL-4 producing CD4 T cells were required to rule out experimental variations (see page 76). For the reduction in the level of anti-HSP-70 IgG, its pre-immunotherapy value had to be above 61 units of optical density (mean+2 S.D. of healthy controls) and it had to drop below 61 units after immunotherapy.

SUSTAINED RISE IN THI AND FALL TN TH2 RESPONSES

All three patients (JB, JH, SM), who had high levels of IL-4 production prior to immunotherapy, showed a decrease in their Th2 responses. This happened after a single dose of M.vaccae. JB, JH and SM also showed increased T h l responses following first three doses of M.vaccae,

although they fell four months after immunotherapy or after four doses of M.vaccae. In the case of JB, he also had influenza during this period which could have accounted for his fall in T h l response. All these patients also became culture negative after immunotherapy. SM also showed a drop in her levels of IgG to HSPs whereas JH showed no changes and JB already had low starting levels.

SUSTAINED RISE IN THI RESPONSE ONLY

Two patients who had normal levels of cytokines (BM,MC) and the CF patient (MM) who had reduced T h l and normal Th2 cytokines showed an increase in their T hl response. BM and MC had an increased level of IFN-y and IL-2 production and showed improvement in their conditions. It appears that an increase in IFN-y was associated with a favourable outcome provided IL-2 production was also increased. BM turned culture negative after immunotherapy. M C’s sputum has remained negative for AFB, and the improvement in her condition has led to her chemotherapy for mycobacterial disease being stopped. MC also had a fall in her IgG to HSPs whereas BM and MM showed no changes.

MM showed a large increase in her IFN-y but her IL-2 production increased only slightly and remained below the levels of healthy controls. This patient showed improvements in her symptoms such as reduction of cough and sputum production for two weeks following the

first two doses of M.vaccae. However, she remained culture positive for

M.avium-intracellulare.

FLUCTUATIONS IN TH1-TH2 CYTOKINE LEVELS

Two patients initially showed an increase in their IFN-y but it decreased later. The levels of IL-2 also flucutated in both patients. Such fluctuating cytokine production following M.vaccae immunotherapy might represent the cumulative effects of immunotherapy and the underlying changes in pathology.

CK, who already had normal levels of IFN-y and IL-2, showed a large increase in the production of IFN-y but not IL-2. Her IL-4 production also rose between the second and third doses of M.vaccae. whereas her IL-2 production fell between the third and fourth doses. She continued to be culture positive for MDR-M.tuberculosis, although her symptoms had gone. Unfortunately, this patient succumbed to her disease one year after the completion of immunotherapy.

JR initially showed an increase in the levels of IL-2 and IFN-y and he was found to improve clinically for the first two months. After the third dose of M.vaccae, his IFN-y levels rose while his IL-2 level dropped; and his clinical symptoms began to regress. This patient’s persisting culture positivity probably reflects the extracellular replication of

M.chelonae. Extracellular growth of M.chelonae would not be arrested by M.vaccae immunotherapy which enhances intracellular killing by macrophages. However, clinical reports a year later found him much improved from his pre-immunotherapy situation.

NO CHANGES IN CYTOKINE LEVELS

Two remaining patients (JBA,MP) showed very little changes in their cytokine levels. JBA showed reduction in the level of anti-HSP IgG. Although he was clinically stable he remained culture positive fo r

M.avium-intracellulare. MP showed no changes in all her parameters. However, she became culture negative after immunotherapy although her sputum still show dead AFB. All her immune parameters had been within the normal range prior to immunotherapy which suggests her cell-mediated immunity had not been compromised. As this patient had normal levels of cytokines prior to immunotherapy, M.vaccae could have further boosted her immune system in killing the mycobacteria although this may not be reflected by changes in cytokine production by the circulating cells. She could have been on the way to recovery before the immunotherapy started. It is also possible that M.vaccae mediated killing o f M.szulgai by an alternate mechanism not involving anti-HSP Igs and T hl-T h2 pathway.

REDUCTION OF ANTI-HSP IgG

Three out of five patients with raised levels of anti-HSP IgG showed their reduction to normal levels. Two of these patients showed improvements in their clinical conditions: SM turned culture negative and MC became sputum negative for mycobacteria. However, JBA remained culture positive although his clinical condition has improved. Of the patients whose level of anti-HSP IgG remained high, JH became culture negative after M.vaccae immunotherapy whereas CK remained culture positive. Therefore, the reduction in the levels of anti-HSP IgG could not be directly linked with change in culture status o r improvements in clinical condition.