Discussion
Cryptococcosis by C.neoformans, can be considered as a life-threatening
condition in HIV-positive patients. There has an increase in the
incidence of cryptococcal meningitis but its prevalence is reducing (7).
The most common route of entry for cryptococcus in immunocompromised
patients is through inhalation of spores or desiccated yeast cells (8).
In patients with immunosuppression, cryptococcus can start causing
symptoms and acute respiratory distress syndrome can rapidly appear as a
consequence. After infecting the lungs, these fungi can spread
hematogenously and reach the CNS (9). Available data propose that
currently there are two mechanisms by which cryptoccocus can enter the
CNS. One is to migrate directly through endothelium by transcytosis and
other one is being carried inside macrophages. Their polysaccharide
capsule has anti-phagocytic propreties (10). There can be several signs
and symptoms for CNS involvement, however the rate of patients who
develop them is low. These manifestations involve headache, nausea,
fever, memory loss, altered level of consciousness, confusion, seizures,
and hearing impairment (1). Cryptoccocal pneumonia manifests as fever,
productive cough, and chest pain and it can radiologically mimic lung
cancer or metastasis, lung tuberculosis, and bacterial pneumonia. It can
also be asymptomatic and diagnosed coincidentally (11). The radiological
findings in immunocompromised patients may include cavitation, lobar
opacities, nodules, pleural effusion, and lymphadenopathy (12).
Patients who are positive for HIV infection specially with low CD4 cell
count and with subacute or chronic headache should be considered as
candidates for lumbar puncture to investigate cryptococcal
meningoencephalitis. In addition to CSF cell count, CSF culture, and
india ink, we can assess CrAg in CSF. We can also detect CrAg in serum.
We can also use blood culture, chest X ray, head CT scan, and MRI (13).
Lateral flow assay (LFA) with a sensitivity of more than 95% and a
specificity of 100% is a new laboratory tool being used for detecting
cryptococcal antigen (1).
The initial therapy should contain antifungal drugs. A two-week therapy
with amphotericin B at 3 mg/kg/day and flucytosine at 100 mg/kg/day as
induction phase. Afterwards, therapy should be continued with
fluconazole for eight to 12 months as consolidation phase (12). Studies
suggested that a combination of amphotericin B with flucytosine can have
a better fungicidal effect with lower risk of failure in treatment
rather than a combination of amphotericin B with fluconazole (14).
A better clinical outcome for patients with meningoencephalitis is
related to the choice of initial therapy and handling raised
intracranial pressure. An elevated opening pressure of more than 25 cm
of CSF requires serial lumbar punctures to reduce the pressure to less
than 20 cm of CSF (15).
As we can see in presented case ART should be delayed at least 2 weeks
after the start of antifungal therapy, due to the occurrence of immune
reconstitution inflammatory syndrome (IRIS) resulting in worsening
symptoms and sometimes death as happened in our patient.