Case report
It was about a 33-year-old man followed since 2017 for IgG4 related
disease. The diagnosis was retained in front of glandular involvement
with xerostomia and xerophtalmia, hypergammaglobulinemia at 28g/L with
IgG level at 23g/L and IGg4 level at 2.9 g/L, hepatic involvement with
cytolysis, cholestasis and positive anti smooth muscles antibodies
(ASMA). Radiologic findings were highly suggestive of malignancy.
Therefore, the patient underwent right nephrectomy with the presence of
IgG4 at direct immunofluorescence technique (DIFT) at the histology.
The patient was treated by corticosteroid therapy at a dose of 0.6
mg/kg/day for 2 months then progressive decrease with improvement in
glandular and hepatic involvement. Six months after treatment
initiation, the patient exhibited an edema of the lower limbs with
hematuria. Biological tests showed proteinuria at 15 ng/24H with a
creatinine value at 413µmol/l. Thus, an impure nephrotic syndrome was
retained and the patient was prescribed RTX as this complication was
thought to be a corticosteroid-resistant IgG4-RD manifestation.
The patient was hospitalized to receive RTX cure. On admission, his
temperature was 37°C without obvious infectious foci. The
pre-therapeutic assessment had shown a CRP at 14 IU, an ESR at 2min, the
absence of hyperleukocytosis, negative SARSCoV-2 PCR and sterile ECBU
culture. The Natremia was normal at 142mmol/l and the AANs were
negative. The chest scanner was without abnormalities.
The patient received his first RTX cure at a dose of 1g. During the
course of this later treatment, he manifested a headach. Pressure blood
measurement showed a hypertensive peak at 150/80mmHg which regressed
spontaneously. Six hours after the end of the treatment, the patient
described paresthesias in the left lower limb with ataxia on walking. He
presented also, a fever peak at 40°C with a rapid alteration of
consciousness, a state of confusion, vomiting with myoclonus and
tremulation without motor or sensory deficit and with normal
osteotendinous reflexes. The patient became polypneic at 28cycles per
minute with crackling rales at lung bases.
A lumbar puncture was performed showing a clear fluid, presence of 100
white elements with 94 lymphocytes, proteinorrachia at 0.8g/L with
normal glycorrhachia at 4mmol/l.
Two hours later he presented a status epilepticus requiring intensive
care with intubation and mechanical ventilation. A cerebral angio-MRI
was performed showing high signal intensity on T2 weightned images and
diffusion weighted images (figure 1).
A second SARSCoV-2 PCR was done and was negative. Viral and bacterial
multiplex PCRs on cerebrospinal fluid were negative. The infectious
tests (HBV, HCV, HIV, Parvo B19, CMV, EBV, Herpes, Mycoplasma and
syphilis serologies as well as Legionella antigenuria) were negative.
ECBU and blood culture test are steriles.
The patient received a bolus of methylprednisone (15mg/Kg/day) for 3
days with intravenous immunoglobulin cures associated with sodium
valproate and he was extubated 48 hours later with a calm awakening and
a gradual recovery of his state of consciousness. The diagnosis of MERS
induced by RTX was most likely.