Medical Bulletin 16/ April/ 2024

Here are the top medical news for the day:

Study reveals new genetic risk factors for HPV infection

A research led by University of Maryland School of Medicine researchers and published in the journal The European Journal of Human Genetics has identified genetic variants that could raise a woman's risk of getting cervical cancer from a high-risk HPV infection.

Human papillomavirus (HPV) is the second most common cancer-causing virus, accounting for 690,000 cervical and other cancers each year worldwide. While the immune system usually clears HPV infections, those that persist can lead to cancer, and a new finding suggests that certain women may have a genetic susceptibility for persistent or frequent HPV infections.

In the study, researchers conducted a genome-wide association study of high-risk HPV infections in a cohort of over 10,000 women. A total of 903 of the participants had high-risk HPV infections when the study began, with 224 participants having HPV infections that resolved, and 679 having persistent HPV infections. More than 9,800 HPV-negative women were in the control group.

The results revealed that the top variant associated with prevalent high-risk HPV infection was located near the LDB2 gene, which encodes for proteins. They found persistent HPV was associated with variants clustered around the TPTE2, a protein encoding gene associated with gallbladder cancer. The genes SMAD2 and CDH12 were also associated with persistent high risk HPV infections, and significant polygenic risk scores.

"We found certain genetic variants were associated with having high-risk HPV infections, while other variants and human leukocyte antigen (HLA) genes were associated with persistent infections, which increase the risk of developing cervical cancer. This is a critical finding that suggests genetic underpinnings for cervical cancer risk. It is the first sufficiently powered genome-wide association study of cervical high-risk HPV infections. Our polygenic risk score models should be evaluated in other populations,” said study leader Sally N. Adebamowo, MBBS, MSc, ScD, Associate Professor of Epidemiology & Public Health at UMSOM

Reference:Adebamowo, S.N., Adeyemo, A., Adebayo, A. et al. Genome, HLA and polygenic risk score analyses for prevalent and persistent cervical human papillomavirus (HPV) infections. Eur J Hum Genet (2024). https://doi.org/10.1038/s41431-023-01521-7

Is there an association between maternal weight and lactation?

A new study published online in the journal Advances in Nutrition analyzed associations between the mother's body size and lactation, including the time of onset, amount of milk produced, and infant consumption of the mother's own milk (MOM).

Breastfeeding is the ideal source of nutrition for almost all infants. However, only 44% of infants worldwide below six months of age are breastfed without supplementary feeds. One common reason is insufficient milk to satisfy the child's needs.While underweight mothers may not have adequate energy stores to form enough milk,obese mothers may be associated with hormonal and metabolic aberrations that suppress lactation.

In the study, researchers included 122 articles, with a total of over 42,500 mothers. The mean maternal age was between 20 years and 35 years. The mean body mass index (BMI) ranged from 16.7 to 31.3 kg/m2. The percentage fat mass ranged from 15.5 to 45.4.

The results showed that underweight or healthy-weight mothers were 35% less likely to experience delayed abundant breast milk production compared to obese or overweight mothers. Maternal BMI didn't affect onset time of copious milk. Infant milk consumption didn't correlate with maternal BMI or fat percentage, possibly due to limited energy intake variation or small sample size for obese women.

The findings suggested that obesity and overweight may delay abundant breast milk onset post-delivery compared to non-overweight mothers, but supporting data is limited due to mixed study results.

"Maternal obesity as a condition that impairs lactation.However, our results did not adequately capture mothers with preterm infants or those with a BMI >30kg/m2, who may be at greatest risk," said the study authors.

Reference: Montana, A. V., Mildon, A., Daniel, A. T., et al. Is maternal body weight or composition associated with onset of lactogenesis II, human milk production or infant consumption of mother's own milk? A systematic review and meta-analysis. Advances in Nutrition 2024. DOI: 10.1016/j.advnut.2024.100228, https://www.sciencedirect.com/science/article/pii/S2161831324000620

Study finds tuberculosis lasting effects on lung health

A new research being presented at the ESCMID Global Congress revealed that tuberculosis (TB) can have a lasting impact on the lungs of individuals who have been successfully treated for the disease.

TB survivors frequently exhibit smaller lungs and narrower airways, resulting in decreased airflow. While antibiotic treatment can cure TB, many individuals still experience lasting lung damage, impacting both their quality of life and life expectancy. However, comprehensive data regarding the specific nature and extent of respiratory impairment among survivors remains scarce.

The study included data on 75,631 individuals from 15 studies conducted in 17 countries with varying TB incidences. Four measures of lung function were included in the analysis: forced expiratory volume in 1 second (FEV1, the volume of air can be forcefully exhaled in one second); forced vital capacity (FVC, the volume of air that can be forcefully exhaled in a single breath); FEV1/FVC ratio; FVC as a percentage of the predicted value (compares the volume to the average of a healthy person of the same age, sex and height).

The results showed that compared to the healthy controls, the participants with prior TB had significantly lower results on all four measures of lung function, with FEV1 more affected than FVC. Further, TB survivors have 65% higher odds of airflow obstruction (AFO) than the healthy controls.

The findings indicated that TB can have long-lasting effects on lung structure and function, resulting in smaller lungs and narrower airways. This can lead to less efficient breathing, especially during activities like exercise.

“Our results strongly indicate that post-tuberculosis lung disease is an under-recognised global challenge – and one that has significant implications for clinical practice and policy. The focus, until now, has been on the treatment of acute TB, but even when treatment is successful, individuals can be left with significant lung damage. This can cause breathlessness that can affect their ability to work and go about their day-to-day lives and reduces their quality of life that suggests that there is an urgent need for evidence-based recommendations on the diagnosis, treatment and management of post-tuberculosis lung disease,” explained lead researcher Dr SharenjaRatnakumar, of St George’s, University of London, London, UK.

Reference: Tuberculosis can have a lasting impact on the lung health of individuals who have been successfully treated for the disease; EUROPEAN SOCIETY OF CLINICAL MICROBIOLOGY AND INFECTIOUS DISEASES; Meeting: ESCMID Global (ECCMID 2024)