Preliminary investigation of lethally toxic sera of sudden infant death syndrome victims and neutralisation by commercially available immunoglobulins and adult sera

Abstract

The aim of the study was to test the hypotheses (i) that sudden infant death syndrome sera are toxic to 11‐day old chick embryos and (ii) that such a toxicity can be counteracted by immunoglobulin or adult sera. Serum samples from 11 SIDS victims and five controls were tested for lethal toxicity in the chick embryo bioassay. Five serum samples were used to challenge chick embryos injected with the following: sudden infant death syndrome serum plus Hank's balanced salt solution; Hank's balanced salt solution alone; sudden infant death syndrome serum plus 3% w/v commercial immunoglobulin; sudden infant death syndrome serum plus 6% w/v immunoglobulin; sudden infant death syndrome serum plus pooled sera of 40 healthy adults. Results obtained revealed that Hank's balanced salt solution, the pooled adult serum and the commercial immunoglobulin were all non‐lethal, in the chick embryo test system. By contrast, 10 sudden infant death syndrome victims yielded sera containing lethal levels of toxin(s) compared to 2/5 controls which was statistically significant (P<0.05, Fischer's exact test). In the tests of sudden infant death syndrome serum plus immunoglobulin or pooled adult serum, the lethality of sudden infant death syndrome serum was abolished in all cases. The reduction in toxicity of individual sudden infant death syndrome serum plus immunoglobulin or pooled adult serum was often statistically significant (P<0.05–P<0.00005, Fischer's exact test). We conclude that lethal levels of toxin are present in sudden infant death syndrome sera and that they can be neutralised by normal immune serum. These results indicate that passive immunisation is a potential treatment to protect babies considered at risk from sudden infant death syndrome.

The role of infection in sudden infant death syndrome

“…Levels of antibodies to the DPT vaccine in the serum of infants correlated with levels of antibodies to the pertussis toxin, TSST and SEC [41]. This paper and that of Sayers et al [42] indicate that passive immunisation of infants with low levels of IgG to the bacterial toxins implicated in SIDS might be another approach to reducing further the incidence of these deaths.…”

Association of Sudden Infant Death Syndrome With VEGF and IL-6 Gene Polymorphisms

“…A prolonged series of studies at Manchester have described the predictive value of the hypothesis [11]. Despite accumulating evidence for a role for infection and inflammation in SIDS, much of the microbiologic evidence has been dismissed as postmortem artefacts.…”

Staphylococcal enterotoxin genes are common inStaphylococcus aureusintestinal flora in Sudden Infant Death Syndrome (SIDS) and live comparison infants

“…The phenomenon of lethal synergy from SIDS nasopharyngeal isolates has been previously demonstrated in a gnotobiotic mouse model (Lee et al, 1987) and in chick embryos (Sayers et al, 1995). Synergy of bacterial toxins with respiratory viral infection or products of cigarette smoke are other pathogenetic pathways to SIDS described in animal models (Sayers et al, 1999). SEs have been proposed to facilitate transcytosis of bacteria across the intestinal barrier (Balaban & Rasooly, 2000).…”