This review is partly composed of the presentation "Cytokine alteration and speculated immunological pathophysiology in silicosis and asbestos-related diseases" delivered during the symposium "Biological effects of fibrous and particulate substances and related areas" organized by the Study Group of Fibrous and Particulate Studies of the Japanese Society of Hygiene and held at the 78th Annual Meeting in Kumamoto, Japan. In this review, we briefly introduce the results of recent immunological analysis using the plasma of silica and asbestos-exposed patients diagnosed with silicosis, pleural plaque, or malignant mesothelioma. Thereafter, experimental background and speculation concerning the immunological pathophysiology of silica and asbestos-exposed patients are discussed.

Background: This study examined the bidirectional and temporal-ordinal relationship between loneliness and back pain. Methods: Data from 7,730 participants in waves 6 (2012–2013), 7 (2014–2015), and 8 (2016–2017) of the national English Longitudinal Study of Ageing were analyzed. Back pain was graded on a scale of 0–10 (0, no discomfort; 10, unbearable pain). Loneliness was measured using the Revised University of California Los Angeles Loneliness Scale. A targeted minimum loss-based estimator was used to examine the bidirectional longitudinal associations between back pain and loneliness. Results: No loneliness in waves 6 and 7 (relative risk [RR]=0.76; 95% confidence interval [CI], 0.61–0.94), no loneliness in wave 6 but loneliness in wave 7 (RR=0.58; 95% CI, 0.50–0.68), and loneliness in wave 6 but not in wave 7 (RR=0.69; 95% CI, 0.57–0.86) were associated with significant risk reductions of back pain in wave 8 compared with the scenario of loneliness in waves 6 and 7. Mild back pain in wave 6 but moderate back pain (RR=0.55; 95% CI, 0.35–0.86) or severe back pain in wave 7 (RR=0.49; 95% CI, 0.34–0.72) showed a significant risk reduction of loneliness in wave 8 compared with severe back pain in waves 6 and 7. Conclusion Loneliness may be a risk factor for back pain, and back pain may be a risk factor for loneliness. The results of this study will inform the development of more effective interventions for loneliness and back pain.

Background: This study examined the bidirectional and temporal-ordinal relationship between loneliness and back pain. Methods: Data from 7,730 participants in waves 6 (2012–2013), 7 (2014–2015), and 8 (2016–2017) of the national English Longitudinal Study of Ageing were analyzed. Back pain was graded on a scale of 0–10 (0, no discomfort; 10, unbearable pain). Loneliness was measured using the Revised University of California Los Angeles Loneliness Scale. A targeted minimum loss-based estimator was used to examine the bidirectional longitudinal associations between back pain and loneliness. Results: No loneliness in waves 6 and 7 (relative risk [RR]=0.76; 95% confidence interval [CI], 0.61–0.94), no loneliness in wave 6 but loneliness in wave 7 (RR=0.58; 95% CI, 0.50–0.68), and loneliness in wave 6 but not in wave 7 (RR=0.69; 95% CI, 0.57–0.86) were associated with significant risk reductions of back pain in wave 8 compared with the scenario of loneliness in waves 6 and 7. Mild back pain in wave 6 but moderate back pain (RR=0.55; 95% CI, 0.35–0.86) or severe back pain in wave 7 (RR=0.49; 95% CI, 0.34–0.72) showed a significant risk reduction of loneliness in wave 8 compared with severe back pain in waves 6 and 7. Conclusion Loneliness may be a risk factor for back pain, and back pain may be a risk factor for loneliness. The results of this study will inform the development of more effective interventions for loneliness and back pain.

Background: This study examined the bidirectional and temporal-ordinal relationship between loneliness and back pain. Methods: Data from 7,730 participants in waves 6 (2012–2013), 7 (2014–2015), and 8 (2016–2017) of the national English Longitudinal Study of Ageing were analyzed. Back pain was graded on a scale of 0–10 (0, no discomfort; 10, unbearable pain). Loneliness was measured using the Revised University of California Los Angeles Loneliness Scale. A targeted minimum loss-based estimator was used to examine the bidirectional longitudinal associations between back pain and loneliness. Results: No loneliness in waves 6 and 7 (relative risk [RR]=0.76; 95% confidence interval [CI], 0.61–0.94), no loneliness in wave 6 but loneliness in wave 7 (RR=0.58; 95% CI, 0.50–0.68), and loneliness in wave 6 but not in wave 7 (RR=0.69; 95% CI, 0.57–0.86) were associated with significant risk reductions of back pain in wave 8 compared with the scenario of loneliness in waves 6 and 7. Mild back pain in wave 6 but moderate back pain (RR=0.55; 95% CI, 0.35–0.86) or severe back pain in wave 7 (RR=0.49; 95% CI, 0.34–0.72) showed a significant risk reduction of loneliness in wave 8 compared with severe back pain in waves 6 and 7. Conclusion Loneliness may be a risk factor for back pain, and back pain may be a risk factor for loneliness. The results of this study will inform the development of more effective interventions for loneliness and back pain.

Background: This study examined the bidirectional and temporal-ordinal relationship between loneliness and back pain. Methods: Data from 7,730 participants in waves 6 (2012–2013), 7 (2014–2015), and 8 (2016–2017) of the national English Longitudinal Study of Ageing were analyzed. Back pain was graded on a scale of 0–10 (0, no discomfort; 10, unbearable pain). Loneliness was measured using the Revised University of California Los Angeles Loneliness Scale. A targeted minimum loss-based estimator was used to examine the bidirectional longitudinal associations between back pain and loneliness. Results: No loneliness in waves 6 and 7 (relative risk [RR]=0.76; 95% confidence interval [CI], 0.61–0.94), no loneliness in wave 6 but loneliness in wave 7 (RR=0.58; 95% CI, 0.50–0.68), and loneliness in wave 6 but not in wave 7 (RR=0.69; 95% CI, 0.57–0.86) were associated with significant risk reductions of back pain in wave 8 compared with the scenario of loneliness in waves 6 and 7. Mild back pain in wave 6 but moderate back pain (RR=0.55; 95% CI, 0.35–0.86) or severe back pain in wave 7 (RR=0.49; 95% CI, 0.34–0.72) showed a significant risk reduction of loneliness in wave 8 compared with severe back pain in waves 6 and 7. Conclusion Loneliness may be a risk factor for back pain, and back pain may be a risk factor for loneliness. The results of this study will inform the development of more effective interventions for loneliness and back pain.