Guidelines in pathology induced by Anisakis Original Article

J. Domínguez Ortega, et al
Fig. 3. Abdominal ultrasonography showing thickened walls of the
intestinal loops and free intraabdominal fluid.
mercial Anisakis simplex extracts at a 1-mg/ml concentration,
with both early (15 min) and late (24 h) readings. A
number of cases of anaphylaxis during skin prick testing
have been reported 13 .
The skin prick tests have low specificity, as they do
not discriminate between true positive results and cross-reactions
to other parasites such as Ascaris or Echinococcus.
The skin tests with a panel of different fish extracts
are consistently negative.
IgE quantitation
The serum levels of total IgE and Anisakis simplexspecific
IgE are assessed using the CAP-radioimmunoassay
technique. Increased levels of both are usually found
and their evolution has been observed to be associated, the
total and specific IgE levels decreasing together over time
if a fish- and cephalopod-free diet is instituted 14 (Fig. 1).
IgE, IgG and IgA immunoblot
These techniques are useful for the differentiation of
cross-reactions from true anisakiasis. Although no homogeneous
pattern is known to exist, in the first case (cross reactions)
the sera recognise exclusively intermediate-molecular weight
antigens when tested against the parasite proteins, while the
sera of patients with true Anisakis infestation will also recognise
low-molecular weight (14 - 30 kDa) antigens15 (Fig. 6).
These low molecular weight antigens are thought to correspond
to so-called secretory/excretory larval antigens
DIETETIC CONSIDERATIONS
When faced with a patient diagnosed of anisakiasis,
the question arises whether a strict fish-free diet is absolu-
270
Figs. 4 and 5. Histopathology study of the surgical specimen of a
patient with suspected anisakiasis. There is a marked eosinophyllic
infiltrate extending even into the muscular layer of the intestinal wall.
tely necessary, and even more so when fish represents a
basic alimentary component in many other conditions such
Fig. 6. IgE immunoblot (from the studies by Dr. Moneo and Dr. Fernández
de Corres). Several intermediate-molecular weight bands
(30 - 50 kDa) as well as other low-molecular weight ones (14 - 30
kDa) can be identified.