Discussion and Conclusions
We obtained two new findings from this case. First, to the best of our
knowledge, this is the first case to use PDF for SCLS. Second, we
determined that the substances that are therapeutic targets for SCLS are
likely to be included in the medium molecule region.
We introduced PDF to treat SCLS. PDF is a blood purification method in
which a dialysate is recirculated to the outside of a hollow fiber while
performing plasma exchange with fresh frozen plasma (FFP) or an albumin
solution using a membrane type plasma separator Evacuer🄬 Plus (Kawasumi
Chemical Industry, Ltd.) EC-2A filter. PDF is said to be able to remove
small and medium-sized harmful substances while retaining useful
substances in the large molecule region, such as immunoglobulin and
coagulation factors. Therefore, the major advantage of PDF compared to
PE is that it can reduce the use of FFP (14, 15). Reducing the use of
FFP can lower the cost of treatment and reduce the risk of blood
transfusion complications.
In this case, PDF showed a remarkable effect, due to which we can
surmise that substances within the treatment target of PDF may be the
cause of SCLS. In Japan, PDF is treated as PE for insurance claims, so
the use of PDFs is limited to those with PE insurance coverage. However,
this patient also had myasthenia gravis and was covered by insurance for
PE, due to which performing PDF was not a problem. In other
circumstances, the cost can be an issue with using PDF. Therefore,
unless the physician is very confident about the diagnosis, PDF should
be used with extreme caution.
The findings obtained in this case can be useful to plan treatment for
SCLS in future cases. If substances in the middle molecular area are
responsible for increased vascular permeability, immunoglobulin and M
protein will not be directly responsible. There are reports of vascular
endothelial growth factor and angiopoietin 2 as substances in the middle
molecular region and they reflected the clinical course(13). Together
with the results of this study, it may be that such substances are the
cause of SCLS.
SCLS is a rare syndrome, difficult to diagnose, and has an uncertain
etiology. Although our patient did not show any hemoconcentration, she
was diagnosed as having SCLS due to prominent hypotension and decrease
in GEDI and hypoalbuminemia. In this case, the recurrence of sepsis
could not be ruled out, but there were no major problems during surgery,
the appropriate antibiotics had been administered, and blood test
results had showed improvement. Finally, we could confidently diagnose
SCLS based on the presence of monoclonal M protein. Other differential
diseases, such as ovarian hyper-stimulation syndrome and hereditary
angioedema were ruled out based on serum estradiol level and C1 esterase
inhibitor level, respectively. Although there have been reports of SCLS
complicated with cancer (8), the relationship between cancer and SCLS is
unclear. In addition, SCLS occurring with myasthenia gravis has not been
reported in the past, and it is unclear whether the two diseases are
related. In this case, it was not possible to completely improve the
vascular permeability. The patient may not have been completely cured
due to persisting malignancy or metastasis. However, PDF may be useful
in overcoming the acute phase of SCLS.
In summary, an 84-year-old woman with a history of myasthenia gravis
underwent surgery for colon cancer-related perforating peritonitis.
After surgery, SCLS developed and was treated using PDF. PDF was
considered to be an effective treatment that covers the therapeutic
target of SCLS. The use of PDF may be considered when treating the acute
phase of SCLS. To the best of our knowledge, this is the first report
using PDF for SCLS.