3 Discussion
CADM typically presents with characteristic cutaneous manifestations of
classic dermatomyositis without muscle involvement; almost all patients
with CADM present at least one characteristic skin lesion[1]. In our
present case, because of the absence of traditional muscle findings and
atypical skin lesions after hospitalization, the diagnosis of CADM can
be a challenge. In this case, facial
erythema
was noticed after induction of labor for a stillborn fetus, and the
symptom vanished after oral prednisone administration. Meanwhile, the
patient presented with no myalgia, and her creatine kinase level was
normal during subsequent
hospitalization.
Patients with CADM are often combined with ILD. It is known
that RP-ILD is more common in the
CADM subset. The patient initially presented with interstitial pneumonia
and then developed refractory respiratory failure very quickly. Despite
maximum respiratory support and the corresponding treatment, the
patient’s status was aggravated continuously with a life-threatening
hypoxemia. The mechanism of onset of RP-ILD is
ill-informed;
reports have suggested that the condition is highly correlated with CADM
and MDA5 antibody positivity[10]. High SF has been shown to be
another important indicator of poor prognosis of RP-ILD in CADM. The SF
levels are reported to be higher with positive anti-MDA5 antibody than
with negative anti-MDA5 antibody and higher in nonsurvivors than in
survivors[11]. Furthermore,
anti-Ro-52 is also a risk factor for ILD in
CAMD[12]. The patient
experienced pneumomediastinum and
pneumothorax with the development of CADM and RP-ILD. Pneumomediastinum
has also been reported to be more common in CAMD patients with positive
anti-MDA5 antibody than in patients with negative anti-MDA5
antibody[13]. These reports indicate that our patient had a high
anti-MDA5 antibody titer, a high anti-Ro-52 antibody titer, a high
ferritin level, and the complications of pneumomediastinum and
pneumothorax, all of which indicated the diagnosis of clinically
amyopathic dermatomyositis and showed a poor prognosis.
ECMO provides temporary cardiopulmonary support in patients with severe
but potentially reversible cardiac and/or respiratory failure
unresponsive to maximal conventional management. While it does not
reverse the underlying lung disease, it acts as a bridge to recovery by
offering patients more time for treatment therapies to take effect. It
can also reduce ventilator-induced lung injury and oxygen toxicity
caused by mechanical ventilation, which can add further damage to
already damaged lungs. Last, chronic systemic disease or refractory
end-stage pulmonary disease, which was resistant to conventional
therapy, was considered a contraindication to ECMO in the past.
Pulmonary interstitial fibrosis associated with RP-ILD in CAMD is a rare
indication for lung transplantation. However, ECMO can provide
additional time for these patients who are being considered for lung
transplant, and there are some reports of lung transplantation for
RP-ILD[14]. In the course of this patient, lung protective
ventilation strategy, lung recruitment maneuver and prone position were
all performed to support ECMO, but pulmonary interstitial fibrosis
gradually occurred, and the patient did not tolerate attempts to wean
from ECMO. Our case indicated that ECMO has shown to be a valid rescue
therapy in acute refractory respiratory failure secondary to RP-ILD and
made further diagnosis and treatment possible. Although this patient did
not completely recover her health at the end, ECMO added time to make an
accurate diagnosis and offered the patient the opportunity for a lung
transplantation.
Tacrolimus, a calcineurin inhibitor, is an effective immunosuppressive
agent for the prevention of organ transplant rejection. However, PRES is
a rare and serious neurologic complication of tacrolimus.
Temporary cessation of tacrolimus
and gradual reduction of the dosage may be effective strategies for
managing PRES. However, these managements include risks of reducing
immunosuppression, thereby leading to acute rejection. In our case, the
strategy is to suspend tacrolimus for one day and gradually reduce the
dosage to 0.5 mg/day. The patient’s
neurological
symptoms improved, and signs of acute rejection were absent.
In conclusion, when patients experience RP-ILD for no apparent reason,
CADM should be considered, especially in patients who are positive for
anti-MDA5 and anti-Ro-52 antibody and have a high ferritin level and
complications of pneumomediastinum and pneumothorax. ECMO should be
considered as a supportive therapy and initiated early in patients in
acute respiratory failure secondary to RP-ILD since it could provide a
true opportunity to improve survival for such a rare disease and its
potentially deadly complications. In cases of refractory respiratory
failure and pulmonary fibrosis, lung transplant may be an option. PRES
is not very common, but more attention should be paid to the patients
who are using immunosuppression drugs. Our findings suggest that
temporary cessation of tacrolimus and dosage reduction may be effective
management strategies for PRES. The results of our case are frustrating,
but more experience and further studies are needed to evaluate the true
value of this method.