Polymyalgia rheumatica pathophysiology
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Rim Halaby, M.D. [2]
Overview
The underlying pathophysiology of polymyalgia rheumatica (PMR) remains unknown.[1] It has been hypothesized that genetic and environmental factors are implicated, particularly due to the seasonal and geographical differences in the prevalence of this disease.[2][3][4] It has also been hypothesized that PMR is associated with infections such as parainfluenza virus type 1,[5] mycoplasma pneumoniae, chlamydia pneumoniae, and parvovirus B19.[6] In addition, histological exam of synovial biopsies of affected individuals revealed mild synovitis with predominance of CD4 T cells and macrophages.[7]
Pathophysiology
- PMR is a chronic inflammatory disease of the articular and periarticular structures of the cervival region, shoulder girdle and hip girdle. The cause of PMR remains unknown; however, there is evidence in the literature of possible involvement of genetic and environmental factors.[1] This hypothesis is supported by the seasonal and geographical variations of the prevalence of PMR. In fact, the incidence of PMR is the highest among patients from northern European descent and Scandanavian countries, which suggests a genetic and/or environmental role in the pathophysiology of PMR.
- Several genes have been reported to be involved in PMR, such as:
- In addition, the association between PMR and infections is another hypothesis for the development of PMR. This hypothesis is supported by the highest incidence of PMR in the time of some infection epidemics. Some of the infections that have been linked to PMR are:
- In addition to the previous hypotheses, it has been postulated that PMR can be explained by an age related dysrregulation in the hypothalamus, pituitary gland and gonads. This disturbance leads to adrenal insufficiency and decrement in dehydroepiandrosterone or androstenedione.[11]
- Imaging studies such as ultrasound and MRI reveal inflammation in the articular and periarticular regions.[1] The examination of histopathological specimens demonstrates mild synovitis with a predominance of T helper cells and macrophages.[7]
References
- ↑ 1.0 1.1 1.2 Kermani TA, Warrington KJ (2013). "Polymyalgia rheumatica". Lancet. 381 (9860): 63–72. doi:10.1016/S0140-6736(12)60680-1. PMID 23051717.
- ↑ Smeeth L, Cook C, Hall AJ (2006). "Incidence of diagnosed polymyalgia rheumatica and temporal arteritis in the United Kingdom, 1990-2001". Ann Rheum Dis. 65 (8): 1093–8. doi:10.1136/ard.2005.046912. PMC 1798240. PMID 16414971.
- ↑ 3.0 3.1 Alvarez-Rodriguez L, Carrasco-Marin E, Lopez-Hoyos M, Mata C, Fernandez-Prieto L, Ruiz-Soto M; et al. (2009). "Interleukin-1RN gene polymorphisms in elderly patients with rheumatic inflammatory chronic conditions: Association of IL-1RN*2/2 genotype with polymyalgia rheumatica". Hum Immunol. 70 (1): 49–54. doi:10.1016/j.humimm.2008.10.011. PMID 19026700.
- ↑ Cimmino MA, Caporali R, Montecucco CM, Rovida S, Baratelli E, Broggini M (1990). "A seasonal pattern in the onset of polymyalgia rheumatica". Ann Rheum Dis. 49 (7): 521–3. PMC 1004141. PMID 2383076.
- ↑ 5.0 5.1 Duhaut P, Bosshard S, Calvet A, Pinede L, Demolombe-Rague S, Dumontet C; et al. (1999). "Giant cell arteritis, polymyalgia rheumatica, and viral hypotheses: a multicenter, prospective case-control study. Groupe de Recherche sur l'Artérite à Cellules Géantes". J Rheumatol. 26 (2): 361–9. PMID 9972970.
- ↑ 6.0 6.1 Elling P, Olsson AT, Elling H (1996). "Synchronous variations of the incidence of temporal arteritis and polymyalgia rheumatica in different regions of Denmark; association with epidemics of Mycoplasma pneumoniae infection". J Rheumatol. 23 (1): 112–9. PMID 8838518.
- ↑ 7.0 7.1 Meliconi R, Pulsatelli L, Uguccioni M, Salvarani C, Macchioni P, Melchiorri C; et al. (1996). "Leukocyte infiltration in synovial tissue from the shoulder of patients with polymyalgia rheumatica. Quantitative analysis and influence of corticosteroid treatment". Arthritis Rheum. 39 (7): 1199–207. PMID 8670331.
- ↑ Haworth S, Ridgeway J, Stewart I, Dyer PA, Pepper L, Ollier W (1996). "Polymyalgia rheumatica is associated with both HLA-DRB1*0401 and DRB1*0404". Br J Rheumatol. 35 (7): 632–5. PMID 8670595.
- ↑ Weyand CM, Hunder NN, Hicok KC, Hunder GG, Goronzy JJ (1994). "HLA-DRB1 alleles in polymyalgia rheumatica, giant cell arteritis, and rheumatoid arthritis". Arthritis Rheum. 37 (4): 514–20. PMID 8147928.
- ↑ Boiardi L, Casali B, Farnetti E, Pipitone N, Nicoli D, Cantini F; et al. (2006). "Relationship between interleukin 6 promoter polymorphism at position -174, IL-6 serum levels, and the risk of relapse/recurrence in polymyalgia rheumatica". J Rheumatol. 33 (4): 703–8. PMID 16583473.
- ↑ Straub RH, Cutolo M (2006). "Further evidence for insufficient hypothalamic-pituitary-glandular axes in polymyalgia rheumatica". J Rheumatol. 33 (7): 1219–23. PMID 16821261.