焦磷酸鈣結晶 | Crystallization Of Calcium Pyrophosphate

焦磷酸鈣結晶

焦磷酸鈣沉積(CPPD)病,通常被稱為“假性痛風”,是一種突然發生的疼痛性關節炎。當焦磷酸鈣晶體位於關節和周圍組織,引起痛風等症狀時,就會發生痛風。然而,痛風是由另一種晶體引起的。這種疾病可能導致持續性關節炎,可能被誤認為是骨關節炎,類風濕性關節炎(RA)或痛風。

隨著年齡的增長,患假性痛風的可能性更大。85歲以上的人幾乎有一半都有這種晶體,但其中許多人沒有症狀

原因

在大多數情况下,晶體形成的原因是未知的,儘管沉積物隨著年齡的增長而新增。因為CPPD傾向於在家族中運行,基因可能起作用。其他可能的因素包括鐵儲存過多;血鎂水准低;甲狀旁腺過度活躍;甲狀腺嚴重不活躍;或血液中鈣過多。

症狀:

假性痛風最常累及膝蓋,但也可累及手腕、肩膀、脚踝、肘部或手部。它會突然出現,持續數天或數周。症狀包括:

關節腫脹

劇烈的關節痛

觸感溫暖的關節

僵硬

發燒

隨著時間的推移,與假性痛風相關的晶體沉積會導致持續的炎症和關節損傷。這可以類比骨關節炎或類風濕性關節炎的症狀,包括:

關節疼痛和僵硬。

輕度炎症。

關節處多節性腫脹-通常是膝蓋、手腕、指關節、肩膀、肘部或脚踝。

關節功能减退。

早晨的僵硬和疲勞。

診斷:

由於CPPD類似於其他形式的關節炎,僅憑體檢很難確診。醫生經常用針頭從受累關節抽取液體,尋找焦磷酸鈣晶體、尿酸晶體(痛風的病因)或感染迹象。X光也可以幫助做出診斷或排除其他引起疼痛的原因。驗血可以幫助排除其他疾病。

治療:

現時還沒有治療方法可以溶解晶體沉積物,但聯合治療可以減輕疼痛和炎症,改善關節功能。治療通常包括非甾體抗炎藥(NSAIDs)或皮質類固醇等藥物。對於劇烈疼痛和腫脹的關節,醫生可能會在關節內插入一根針,去除一些關節液,然後在關節內注射皮質類固醇以減輕炎症,並使用麻醉藥物使其暫時感覺好些。

在嚴重的情况下,手術替換受損的關節是一種選擇。

自理: 除了採取處方治療,重要的是休息疼痛的關節。冰袋有助於減輕與耀斑相關的疼痛和炎症。超重會新增體內的炎症,囙此通過運動和健康均衡的營養來保持健康的體重是很重要的。(1)


關於焦磷酸鈣結晶的部份研究:

  • 焦磷酸鈣結晶溶解(2)
  • 溶解草酸鈣結晶(3)
  • 肌醇六磷酸六鈉鹽抑制主動脈瓣鈣化的形成和發展(4)
  • 多磷酸鹽有效溶解人工合成和離體焦磷酸鈣晶體(5)

Crystallization of calcium pyrophosphate

Calcium pyrophosphate deposition (CPPD) disease, commonly called “pseudogout,” is a painful form of arthritis that comes on suddenly. It occurs when calcium pyrophosphate crystals sit in the joint and surrounding tissues and cause symptoms like gout. Gout, however, is caused by a different type of crystal. The disease may cause lasting arthritis that may be mistaken for osteoarthritis, rheumatoid arthritis (RA) or gout.

Developing pseudogout is more likely as a person ages. Almost half of people over 85 have the crystals, but many of them don’t have symptoms
Causes
In most cases, the cause of the crystal formation is unknown, although deposits increase as people get older. Because CPPD tends to run in families, genes may play a role. Other possible factors in its development include excess stores of iron; low blood magnesium levels; an overactive parathyroid; a severely underactive thyroid; or excess calcium in the blood.
Symptoms
Pseudogout most often affects the knees, but can also involve the wrists, shoulders, ankles, elbows or hands. It comes in episodes that can arrive suddenly and last for days or weeks. Symptoms include:
Swelling of the affected joint.
Intense joint pain.
Joint that is warm to the touch.
Stiffness.
Fever.

Over time, the crystal deposits associated with pseudogout can cause ongoing inflammation and joint damage. This can mimic the symptoms of osteoarthritis or rheumatoid arthritis, including:
Joint pain and stiffness.
Low-grade inflammation.
Knobby swelling at the joint – typically the knees, wrists, knuckles, shoulders, elbows or ankles.
Decreased function of the joint.
Morning stiffness and fatigue.
Diagnosis
Because CPPD resembles other forms of arthritis, it is difficult to diagnose based on a physical exam alone. Doctors often use a needle to take fluid from an affected joint to look for calcium pyrophosphate crystals, uric acid crystals (the cause of gout) or signs of infection. X-rays can also help make the diagnosis or rule out other causes of pain. Blood tests can help exclude other diseases.
Treatment
There’s no treatment available to dissolve the crystal deposits, but a combination of treatments can relieve pain and inflammation and improve joint function. Treatment often includes medications such nonsteroidal anti-inflammatory drugs (NSAIDs) or corticosteroids. For acutely painful and swollen joints, your doctor may insert a needle into the joint to remove some of the joint fluid and then inject the joint with a corticosteroid to decrease inflammation and a numbing medication to make it feel better temporarily.
In severe cases, surgery to replace damaged joints is an option.
Self Care
In addition to taking prescribed treatments, it is important to rest painful joints. Ice packs can help reduce the pain and inflammation associated with flares. Excess weight increases inflammation in the body, so it’s important to maintain a healthy weight with exercise and healthy, balanced nutrition.(1)

Some studies on the crystallization of calcium pyrophosphate are as follows

  • Crystallization and dissolution of calcium pyrophosphate (2)
  • Dissolution and crystallization of calcium oxalate (3)
  • Inositol hexaphosphate hexasodium inhibits the formation and development of aortic valve calcification (4)
  • Polyphosphate effectively dissolves synthetic and isolated calcium pyrophosphate crystals (5)

Refs:

  1. https://www.arthritis.org/diseases/calcium-pyropho...
  2. R Cinia, D Chindamob, M Catenacciob, S Lorenzinib, E Selvib, F Neruccib, M P Picchib, G Bertib, R Marcolongob. Dissolution of calcium pyrophosphate crystals by polyphosphates: an in vitro and ex vivo study. http://dx.doi.org/10.1136/ard.60.10.962
  3. Shouwu Guo, Michael D. Ward, Jeffrey A. Wesson. Direct Visualization of Calcium Oxalate Monohydrate Crystallization and Dissolution with Atomic Force Microscopy and the Role of Polymeric Additives. Langmuir 2002, 18, 11, 4284–4291. Publication Date:May 1, 2002. https://doi.org/10.1021/la011754+
  4. A.Zabirnyka, M.D.FerrerbdM.BogdanovaaM.M.PérezbC.SalcedobM.-L.KaljustoceJ.-P.E.KvittingeK.-O.StensløkkenaJ.PerellóbfJ.Vaagec. SNF472, a novel anti-crystallization agent, inhibits induced calcification in an in vitro model of human aortic valve calcification. Vascular Pharmacology Volumes 122–123, November–December 2019, 106583. https://doi.org/10.1016/j.vph.2019.106583
  5. R Cinia, D Chindamob, M Catenacciob, S Lorenzinib, E Selvib, F Neruccib, M P Picchib, G Bertib, R Marcolongob. Dissolution of calcium pyrophosphate crystals by polyphosphates: an in vitro and ex vivo study. http://dx.doi.org/10.1136/ard.60.10.962