Lung infection likely triggered CAD after COVID-19: Case study
Woman’s symptoms worsened with bacterial infection
A Japanese woman developed cold agglutination disease (CAD) following COVID-19 and a secondary bacterial infection in the lungs that may have worsened her symptoms, a case study showed.
“There is a need for continuous observation to evaluate whether COVID-19, even when it does not require hospitalization, is related to the development of secondary infections,” which could complicate the course of CAD, the researchers wrote.
The case report, “Multiple lung abscesses and cold agglutinin syndrome following coronavirus disease 2019: a case report,” was published in BMJ Case Reports.
In CAD, self-reactive antibodies, called cold agglutinins, attack red blood cells at cold temperatures, causing their destruction and leading to anemia, or lower-than-normal counts of red blood cells.
Primary CAD occurs on its own due to an unknown cause, whereas secondary CAD unfolds in the context of another condition, such as an infection, a cancer, or another autoimmune disease. SARS-CoV-2, the virus that causes COVID-19, has been identified as a potential trigger of new or worsening CAD symptoms in several case reports.
Brown urine, chest pain prompt hospital visit
A team of researchers in Japan described the case of a 69-year-old woman whose symptoms of CAD likely worsened with a bacterial lung infection that developed after SARS-CoV-2 infection.
The woman, who had a gum infection, high blood pressure, and abnormal levels of fatty molecules in the blood, visited the hospital for brown-colored urine and chest pain.
Previous, recent exams had shown multiple masses in her lungs, and high blood levels of bilirubin, a yellow pigment that forms when red blood cells are destroyed. Previous treatment with amoxicillin, an antibiotic, had not improved her condition.
She had received her fourth dose of Pfizer-BioNTech’s mRNA-based BNT162b2 vaccine seven months earlier.
On physical examination, doctors heard decreased breathing sounds, which may indicate the presence of air or fluid in the lungs, or reduced airflow to part of the lungs. They also noticed jaundice, a yellowing of the skin and white parts of the eyes that’s linked to blood bilirubin buildup.
A blood workup revealed a lower-than-normal number of red blood cells and low levels of hemoglobin, the protein in red blood cells that carries oxygen. There were also other markers of red blood cell destruction. The number of immune cells was higher than normal, which could be a sign of infection.
A direct Coombs test came back positive for CAD-related immune proteins attached to the woman’s red blood cells, but negative for a type of antibody associated with attacks against red blood cells at warm temperatures. The level of cold agglutinins was very high.
A chest radiography, or X-ray, showed multiple fluid-filled pockets, known as abscesses, in both lungs. Their presence was confirmed on a CT scan, which showed nodule consolidation, a phenomenon that occurs when air is replaced by fluid or moved out by bacteria.
When the doctors checked for the presence of SARS-CoV-2 in a swab test, the result came back positive; she also had high levels of antibodies against the virus. These results suggested that she had COVID-19 “some time ago,” and therefore, “she did not receive any specific treatment for COVID-19,” the researchers wrote.
Instead, the woman was given piperacillin/tazobactam — an antibiotic with a broader spectrum than amoxicillin — three times a day. On her second day in the hospital, her hemoglobin levels had dropped even further, and she required blood transfusions.
During the three weeks she was hospitalized, her clinical condition improved, her hemoglobin levels nearly doubled, and her cold agglutinin levels were gradually reduced.
“Eight weeks after presentation, cold agglutinin [levels] normalized, and chest radiography showed only slight shadows,” the researchers wrote, adding that “there were no treatment-related adverse effects.” At this point, the levels of red blood cells and hemoglobin were also within the normal range.
“The secondary [CAD] and lung abscesses in this patient improved spontaneously without any COVID-19-specific treatment,” the researchers wrote. “Therefore, although COVID-19 is thought to play a central role, bacterial infection might be an exacerbating factor.”
Notably, analysis of her lung mucus found no abnormalities in terms of microbes that could be causing a lung infection. “Therefore, whether her radiographic abnormalities were induced by bacterial infection was unknown,” the team wrote.
Still, several of the lung abnormalities and the fact that her condition improved after broad-spectrum antibiotics suggest that “bloodstream infections from [gum infection] caused secondary lung abscesses in this patient,” the researchers wrote.
They also noted that it is possible that the bacterial lung infection and lung abscesses developed as a complication of COVID-19, as there have been reports suggesting as much.
The case suggests that “patients can develop secondary [CAD], which could worsen owing to bacterial infections after COVID-19,” the researchers wrote. “More case reports are needed to establish the association of lung [abscesses] with secondary [CAD],” they said.
About the Author
