I did not post last time, I should apologise for that.
The last topic that I wanted to cover is about:
- Osteoarthritis and rheumatoid arthritis
Without further ado, let’s get onto it.
Definition: Form of arthritis(A#1) which is acute and inflammatory.
Causes: Precipitation of monosodium urate crystals in joints.
- Hyperuricemia- Hyper- means high, uric- means uric acid and –emia means presence in blood. Therefore, it means presence of high uric acid in blood. It is caused by
- Mainly under-excretion of uric acid that could occur because of renal failure.
- Rarely (around 10%) by Lesch-Nyan syndrome (A#2), thiazide diuretics (diuretic for hypertension that inhibits Na-Cl symporter in distal convoluted tubule (DCT) and promoting uric acid reabsorption in PCT), renal failure.
- Alcohol use
- Its metabolites compete with uric acid in kidney for excretion sites therefore leads to accumulation in blood.
- It has been found that diabetics are 20% more likely to develop to gout. To read more about it, you can visit here.
- Most of the times with association of diabetes, it increases uric acid level in blood.
- It occurs due to increased insulin resistance in obese people (due to excess lipid presence in the liver) which reduces renal excretion of uric acid.
- Male sex
- It has been discovered that females, during reproductively active age i.e. before menopause, excretes uric acid more due to estrogen hormone.
A#1. Arthritis: Joint swelling and stiffness. There are lots of types of it. Some of them are Rheumatoid arthritis, osteoarthritis, reactive arthritis, gout etc.
Symptoms: Joint pain, tenderness, redness and swelling, difficulty in moving or decrease in the range of motion. Sometimes, mild fever, appetite loss and tiredness.
Causes: May be caused by wear and tear of cartilage (osteoarthritis) or by autoimmune disorder where immune system attacks self cells (rheumatoid arthritis) or by food poisoning and STI by Chlamydia (reactive arthritis).
Treatment: NSAIDs like ibuprofen (Advil) for inflammation, salicylates or aspirin i.e. blood thinner and anti-inflammatory drugs, cortisone drugs which are also anti-inflammatory.
A#2. Lesch-Nyan syndrome: An X-linked recessive defect of purine salvage (degradation process of nucleotides where purine bases are formed again). In child, it is easily characterised by presence of sodium urate crystals that look like yellow-orange sand in diaper.
Cause: Absent Hypoxanthine Guanine Phosphoribosyltransferase (HGPRT). It converts hypoxanthine into inosine monophosphate i.e. IMP and Guanine into GMP. Bacause of this, excess hypoxanthine converts into xanthine and uric acid by xanthine oxidase enzyme.
Symptoms: Hyperuricemia, gout, self harming and aggression, retardation.
Treatment: Though, it itself is uncurable, the life of the person could be prolonged till his (Q#1) teen. The drugs used are febuxostat (inhibits uric acid formation), allopurinol (also used for kidney stones), diazepam and levodopa/carbidopa.
Q#1. Why I said Lesch Nyan syndrome is a disease of ‘Him’ mostly?
A#1. Because I can feel the pain of other males. Just kidding. Actually, as I said, it is X-linked recessive disorder. This means, the mutated or defected gene in absence of any dominating or wild gene, could easily expressed itself. Which is very likely to happen in males as they have only one X chromosome.
In females (XX), even if there is one recessive gene, the other normal gene will compensate its effect.
Therefore, all X-linked recessive disorders are more likely to occur in males.
- Uric acid crystal presence in joints. Well, no big deal. What makes it unique is that this presence is unsymmetrical i.e. any one sided joint could be affected. Atleast, initially. Later multiple joints could be affected.
- Joint gets swollen, painful and often red.
- Commonly affected joint is in big toe i.e. Metatarsophalangeal joint.
- Long accumulation of urate crystals can lead to tophus formation (behind olecranon bone of elbow i.e. olecranon bursa and external ear).
- Frequent and acute formation after some trauma, dehydration, alcohol and foods like sea food and red meat as they have high purine content.
Treatment: For acute attacks glucocorticoid (for those who have risk using NSAID), indomethacin (an NSAID) are used.
For chronic cases, xanthine oxidase inhibitors are used. We have already talked about the drugs already i.e. feuxostat and allopurinol (A#2).
Osteoarthritis and Rheumatoid arthritis
- It is a mechanical damage and degenerative joint disorder caused by wear and tear of articular cartilage.
- Risk factors-
- Joint trauma
- Age (risk increases with age)
- Female sex
- Overweight. Just think of an old female with obesity and joint trauma ;).
- In joints we see,
- Osteophytes (bony lumps or bone spurs), tiny growth on bones.
- Thickening of bones at joints called subchondral sclerosis and cysts.
- Joint swellings like heberden nodes at distal interphalangeal joints (DIP) and bouchard nodes at PIP.
- Pain and tenderness in joints after use which improves with rest. (Remember this, there are some important distinguishing features like this I will be comparing)
- With use of weight bearing joints like knee, the cartilage, it loses its structure medially i.e. becomes bowlegged.
- NSAIDS like aspirin, ibuprofen (Advil)
- Analgesics like Acetaminophen that block pain signaling.
Rheumatoid arthritis (RA):
- It is an autoimmune disoreder.
- In this, a pannus i.e. an extra growth of proliferative granulation tissue (A#3) is induced by inflammation.
- This pannus abrades the bone and cartilage.
- Risk factors-
- Older age like 40-60 years old.
- Female (like osteoarthritis and unlike gout).
- Impairment of the function of HLA-DR4 (Human Leukocyte Antigen subtype). It is found in WBC and presents peptide (foreign) antigens to immune system. Therefore, impairment of this function could lead to failure of differentiation of foreign objects from own cells.
- High presence of rheumatoid factor. These are IgM antibodies that target healthy tissues and IgG antibodies. Also found in Sjogren, endocarditis, hepatitis and lupus. Therefore, its specificity is low.
- Founding anti-CCP or anti-cyclic citrullinated peptide antibody is more specific for RA.
- In joints we see,
- Swelling of soft tissue.
- Joint space narrowing.
- Baker’s or popliteal cyst- A synovium lined subchondral cyst present at knee back which continues with joint space. Whenever it ruptures, causes pain.
- Losing of bone mass near to joint i.e. juxta-articular osteopenia.
- Pain and swelling of joints.
- More at beginning of the day and improves with use.
- Symmetric joint involvement unlike osteoarthritis.
- Fever, fatigue and weight loss i.e. non specific systemic symptoms are also found unlike osteoarthritis.
- Swan neck and ulnar finger deviation (A#4) is found.
- Unlike OA, no Metacarpopharyngeal (MCP) joint is involved and Carpometacarpal (CMC) joint is involved. But like osteoarthritis, Proximalinterphalyngeal (PIP) joint is involved.
- NSAIDs (like OA)
- Methotrexate and sulfasalzine. MTX boosts anti-inflammatory state by enhancing the level of adenosine. These both are DMARD i.e. disease modifying anti-rheumatic drugs that alters the symptoms rather than improving them.
- Antibodies like TNF-alpha (A#5) inhibitors.
A#3. Granulation tissue: It is a new tissue formed during healing process. It could be either healthy or unhealthy.
- Healthy granulation tissue: Indicates ongoing healing. Pink in color.
- Unhealthy granulation tissue: Indicates wound infection. Brownish red in color.
A#4. Ulnar finger deviation: When metacarpopharyngeal joint is swollen, the fingers deviates towards the side of the ulna bone i.e. outwards of the body.
A#5. TNF-alpha: A inflammatory cytokine produced by monocytes or macrophages (monocytes in interstitial spaces). TNF-alpha stimulates the formation of interleukin 1 and 6 that destroys cartilage and bony tissue. This leads to autoimmune condition.
Finally, I have completed. You have fair idea now how to differentiate between OA and RA. Also what is gout, what symptoms are there and why it occurs, how to avoid it etc and etc.
Before finishing I want to say this.
This got longer than expected. Not because there was too much to write (not this particular blog but last 2 also as I was thinking to include these 3 into one. lol) about but also because I skipped 1 week. I greatly regret that. But… well, what can I say! I was busy and unable to write and upload it. Even many times I am unable to upload medical shorts on instagram, facebook, twitter and koo. Though, it is my bad practise to avoid that. Therefore, I am working on it and trying to adjust this with my new routine. You may have known if you have read about me that I am studying medicine in Ukraine. And now, my university classes has started again, therefore its taking time to adjust accordingly. But everyone else is also busy. They don’t stop, then why should I. Especially if I have just started. I am far from the glory of billions and trillions of viewers ;). But still, I will be sticking and uploading more medicinal topics for my friends and fellow readers.
I want to finish this blog with a question that I had in mind from very long.
Q#2. Do you know what are the basic differences between X-ray, CT scan and MRI?
A#2. X-Ray: High energy electromagnetic radiations that penetrates the low density materials like skin and other soft tissues, cartilage etc.
- High density materials like bone or a tumor also, doesn’t allow these radiations to pass through. Hence, a white shadow of these structures appear on the black film. Therefore, very much used to detect any bone fracture or lung cancer.
- Also used to detect other lung conditions like pneumonia. You may have been advised to have X-ray for covid19 (#covid19) diagnosis. Pneumonia is very much associated with covid19. (Have you read my covid related articles? If not than you may want to go after reading this. These were some of my initial works. Let me know if you have liked it.)
- Creates 2D images.
Due to X-Ray being a high energy radiation, it is not recommended to do it frequently as it can cause mutations in your genetic material. Therefore, one may not have a tumor earlier but can develop after X-ray. It is true with exaggerated tone.
CT-Scan: Computed tomography. Think of it roughly as image created with multiple X-ray machines which is combined with computer technology.
- Using ionising radiations, hence it is also a mutagen (mutation causing agent). Though, don’t be scared as the risks are very low. Remember, my earlier statement is just an exaggeration to put into your mind about the possible risk and nothing more.
- It is used for detailed image capturing and understanding.
- Creates 3D, 360o image.
MRI: Magnetic Resonance Imaging. What makes it special is its using non-radiating images.
- As the name says, it uses strong magnetic fields and radio frequencies to create a 3D image.
- Also used for detailed images for structures like soft tissues, internal body structures.
- 3D image is produced.
Thank you for your time. Will upload another article soon. Comment below if you have any question or query.