Research news in brief

Home palliative care doubles as need increases overall in Australia

The number of Medicare-subsidised palliative care services received by Australians in their own home almost doubled between 2015–16 and 2019–20, according to a report from the Australian Institute of Health and Welfare (AIHW). The report, Palliative care services in Australia, shows home visits for palliative care specialist services increased by an average of 18% annually over the 5-year period, with a total of 2240 patients receiving home visits in 2019–20. However, most palliative care services continue to be received in a hospital or surgery, with these services increasing by 12% over the same 5-year period. The report also includes updated information on palliative care services provided in hospital, and for people living in residential aged care. Prior to the COVID-19 pandemic, almost 83 500 palliative care-related hospitalisations were recorded in 2018–19, an increase of 29% between 2014–15 and 2018–19. Of the 244 300 people living in permanent residential aged care in 2019–20, 3200 (1.3%) were appraised as needing palliative care services. Of these, almost one in three (27%) had been diagnosed with cancer. The types of cancer most commonly reported were lung (18%) and prostate cancer (14%). These data only reflect whether a resident was appraised as needing palliative care, rather than whether they actually received the services. Information on actual service provision is a significant gap in the national data. Furthermore, national reporting on the need for palliative care in residential aged care is likely to be an underestimate, as available data are based on a funding instrument, rather than providing a comprehensive, diagnostic assessment.

Methotrexate users have reduced immune response to mRNA COVID-19 vaccine

Up to a third of patients taking methotrexate – a common treatment for immune-mediated inflammatory diseases (IMID) such as rheumatoid arthritis, psoriasis and psoriatic arthritis – failed to achieve an adequate immune response to mRNA COVID-19 vaccines in a small study published in the Annals of the Rheumatic Diseases. While mRNA COVID-19 vaccines have been shown to produce an effective immune response in over 90% of healthy adults in clinical trials, it is unknown whether the immune response is as robust in patients with IMID who may also be taking immunomodulatory medications. The authors assessed the immune response to the mRNA Pfizer–BioNTech COVID-19 vaccine in 82 patients with IMID (mainly psoriasis, psoriatic arthritis and rheumatoid arthritis) receiving methotrexate or an alternative immunomodulator (mainly tumour necrosis factor inhibitors and other biologics) at two centres: New York University Langone Health and FAU Erlangen-Nuremberg and Universitatsklinikum Erlangen in Germany. The study found that the Pfizer–BioNTech vaccine induced adequate antibody levels in up to a third fewer patients receiving methotrexate compared with healthy participants and patients with IMIDs on the other immunomodulatory drugs. Adequate antibody levels were produced in over 90% of the 208 healthy participants and 37 patients taking biologic or non-methotrexate oral treatments but in only 62% of the 45 patients taking methotrexate. Furthermore, while the vaccination induced activated CD8+ T cell responses in healthy participants and patients with IMID not taking methotrexate, this same induction was not seen in patients taking methotrexate. T cells are another part of the body’s immune defence system. This is an observational study, and as such, can’t establish causality.

Hidden malaria life cycle discovered in the spleen

Studies published in PLOS Medicine and the New England Journal of Medicine, have found large numbers of malaria parasites hiding in the human spleen where they actively multiply in a previously unrecognised life cycle. Until now, it was thought that once malaria parasites reached the blood stream, they circulated and multiplied only in the peripheral blood. Research from the Menzies School of Health Research and the University of Paris, with partners in Indonesia, found that in chronic malaria, concentrations of parasites were hundreds to thousands of times higher in the spleen than found in the peripheral blood. The researchers examined spleens from people in Papua, Indonesia, undergoing spleen removal mostly following road accidents. They found that the patients generally had no symptoms of malaria before having their spleens removed, but 95% of patients had large numbers of live parasites hiding in the spleen. “Our findings redefine the malaria life cycle. Chronic malaria should be considered predominantly an infection of the spleen, with just a small proportion circulating in the blood,” lead author Dr Steven Kho said. “Accumulation of parasites in the spleen was found with both major Plasmodium species causing malaria, but was particularly apparent in Plasmodium vivax, where over 98% of all the parasites in the body were hiding in the spleen.” The studies also found that the human spleen traps large numbers of young red blood cells, called reticulocytes, which are Plasmodium vivax can infect.

Short-sighted view of sleep and screen time

Research from Flinders University indicates people with near-sightedness or myopia are more likely to experience poorer sleep quality than people with normal vision. The study, published in Sleep, indicates that people with short-sightedness have more delayed circadian rhythms and lower production of melatonin — a hormone secreted in the brain and responsible for regulating sleep at night — compared with people with normal vision. The findings show that the participants with myopia take longer to fall asleep, sleep for shorter periods of time at night and are more likely to go to bed later or be “night owls” compared with those with normal sight. These sleeping habits were related to people with myopia spending more time on computers and other digital devices or studying before going to bed. The circadian timing and production of melatonin was measured in both people with myopia and people with normal sight. All participants were university students, aged in their 20s. Melatonin is a hormone secreted by brain’s pineal gland to maintain the body’s sleep–wake cycle and circadian rhythms. We produce melatonin soon after the onset of darkness, peaking our secretion between 2am and 4am. Levels of melatonin were measured in participants through saliva and urine samples. The participants with myopia had significantly delayed circadian rhythms and lower outputs of melatonin compared with normal sighted participants.