Discussion
The immunocompromised patient was diagnosed with varicella caused by
primary VZV infection based on the results of physical, blood, and
histopathological examinations. The patient was also diagnosed with CMV
pneumonia based on the results of CMV antigen test in the blood and the
findings of chest CT; the previous studies reported that CMV pneumonia
on CT is mainly detected as ground-glass opacities 7and varicella pneumonia mainly as nodular lesions 8.
The onset of varicella preceded that of CMV pneumonia by a few days.
Three mechanisms have been proposed for the development of adult-onset
varicella: i) the reactivation of latent VZV, ii) reinfection by VZV of
a different genotype from that of latent VZV, and iii) primary VZV
infection. In the case of varicella caused by the reactivation of latent
VZV, VZV-specific IgG potentially increases commonly from a certain
level, whereas VZV-specific IgM does not. In the case of varicella due
to reinfection by VZV of a different genotype, VZV-specific IgM
potentially increases, whereas VZV-specific IgG appears to rapidly
increase commonly from a certain level at an early time point from the
onset 9. In the case of varicella caused by primary
VZV infection, VZV-specific IgM definitely increases, whereas
VZV-specific IgG gradually becomes elevated over 2-3 weeks from a
negative level. Increases in VZV-specific IgM were followed by a gradual
elevation in VZV-specific IgG over 2 weeks from a negative level in the
present case, which was compatible with primary VZV infection.
VZV-specific IgG levels in SLE patients previously infected by VZV were
previously reported to be significantly elevated regardless of total IgG
levels through the significant activation of B-cells to specific
antigens as the pathogenesis of SLE; however, total IgG and complement
factor 3 levels sometimes decrease with an increase in the disease
activity of SLE 10. In the present case, the level of
VZV-specific IgG in the early stage of varicella was low, which
indicated primary VZV infection in our patient.
Cases in which varicella due to the reactivation of or reinfection by
VZV preceded CMV reactivation have been reported. In an experiment on
monkeys, Ohtaki et al . showed that CMV was reactivated after an
inoculation with VZV 11. However, primary VZV
infection followed by CMV reactivation has not been reported in humans.
This is the first human case of primary VZV infection leading to the
reactivation of CMV. Dermatologists need to consider CMV reactivation
with the appearance of varicella caused by any type of VZV infection,
including reactivation, reinfection, and primary infection.
Acknowledgment: None
Statement of Ethics: This study protocol was approved by The
Ethics Committee of The Jikei University School of Medicine and the
patient provided written informed consent.
Consent statement: Written informed consent was obtained from
the patient to publish this report in accordance with the journal’s
patient consent policy.
Data Availability Statement: Additional data sharing is not
applicable to this article due to ethical restrictions.