Woman’s ALS-like Symptoms Linked to Retrovirus in Case Report
Treatment of people whose symptoms are suggestive of amyotrophic lateral sclerosis (ALS) but likely linked to a retrovirus called human T-cell lymphotropic virus type I (HTLV-I) should focus on alleviating symptoms and lowering the viral load, a case report highlights.
The report, “Human T-cell Lymphotropic Virus Type I Associated with Amyotrophic Lateral Sclerosis Syndrome: Immunopathological Aspects and Treatment Options,” was published in the journal Cureus.
Human T-cell lymphotropic virus type I (HTLV-I) is a retrovirus that infects immune T-cells. It has been associated with different types of blood cancers, infectious myelopathies (spinal cord infections), and ALS.
Cases are known of patients showing mixed symptoms of multiple disorders associated with HTLV-I, which in some instances can make it difficult to determine appropriate treatment.
Physicians in Colombia described a 49-year-old woman who tested positive for HTLV-I at their hospital, and showed signs of motor neuron disease — disorders in which the nerve cells responsible for controlling voluntary movements become damaged — that were suggestive of ALS.
The woman was from Buenaventura, a region in Colombia where HTLV-I is considered endemic, meaning always present in the population at a given frequency.
She had no relevant medical history, but noted progressive symptoms of pain and weakness over the previous nine months. These symptoms had started in her legs, and had progressively started to affect her arms.
She also had difficulties speaking (dysarthria), swallowing, and supporting her head and body. Eventually, she lost all mobility and became bedridden.
Lab tests found no signs of a metabolic disorder or an infectious disease, and no abnormalities in her gastrointestinal (GI) tract.
However, a blood test indicated she was producing antibodies against HTVL-I, suggesting that she could have been infected by the virus. Still, no antibodies were found in her cerebrospinal fluid (CSF; the fluid that circulates in the spinal cord and brain).
Subsequent MRI scans found brain lesions, and signs of nerve degeneration that did not compromise the spinal cord.
Electrophysiology studies also found abnormalities in the transmission of electrical signals in the nerves of her legs, while electromyography studies found signs of denervation (loss of nerve supply) in the muscles of her legs, arms, and neck, which were all indicative of a motor neuron disease.
Of note, electrophysiology studies assess the generation and transmission of electrical signals in neurons, or nerve cells, while electromyography does the same thing in muscles.
Based on these findings, physicians concluded the woman had a motor neuron disease and was likely “in the asymptomatic carrier phase for the HTLV-I virus.” Nevertheless, they did not rule out the possibility that her symptoms could be a direct result of the virus itself.
“Patients infected by the virus can remain in the state of being asymptomatic carriers for a long time,” the researchers wrote, adding that assessing the levels of antibodies against HTVL-I in the blood and CSF “is important to differentiate between patients with high viral load and ALS-like symptoms directly affected by the virus and patients who are asymptomatic carriers with low viral load.”
The woman was started on riluzole (brand name Rilutek, marketed by Sanofi), an approved oral treatment for ALS, along with methylprednisolone, an anti-inflammatory, for three days. This was followed by prednisone, a corticosteroid, and gabapentin-type pain modulators as her symptoms improved. Rehabilitation and integral care were also given before she was discharged.
“The HTLV-I virus is associated with central and peripheral nervous system involvement,” and treatment should focus “on symptomatic management and eliminating infected cells to reduce the viral load by using such medications as steroids, valproic acid, the antiviral zidovudine, and mogamulizumab,” the authors concluded.