🧵 Procalcitonin (PCT) –
Tweet 1:
Procalcitonin- once just a peptide in calcitonin synthesis, now a powerful biomarker in infection & sepsis care. But when should we trust it, and when not? 🧵@IhabFathiSulima @DrAkhilX @CelestinoGutirr #MedTwitter #Rheumatology #ID
Tweet 2 (Basics):
🔹 What is Procalcitonin?
•Precursor of calcitonin, normally produced in thyroid C-cells.
•During bacterial infection, PCT is released from multiple tissues in response to endotoxins & cytokines (IL-1β, TNF-α).
•Viral infections usually suppress PCT.
Tweet 3 (Why important?):
✨ PCT rises early (within 6–12 hrs) in systemic bacterial infection → helps clinicians:
•Differentiate bacterial vs viral infections
•Assess sepsis severity
•Guide antibiotic decisions
Tweet 4 (Interpretation):
📊 Levels & meaning (general guide):
•<0.1 ng/mL → Normal
•0.1–0.25 → Low likelihood of bacterial infection
•0.25–0.5 → Possible bacterial infection
•0.5 → Suggestive of bacterial infection/sepsis
(Higher = more severe infection)
Tweet 5 (Pros):
✅ Advantages of PCT:
•Rises earlier than CRP in sepsis
•Falls rapidly with infection control → good for monitoring
•Useful in ICU, pneumonia, sepsis management
•Helps reduce unnecessary antibiotics
Tweet 6 (Cons & pitfalls):
⚠️ Limitations:
•Can rise in non-infectious inflammation (major surgery, trauma, burns, CKD)
•May not rise in localized infections (e.g., abscess)
•Viral infections may keep it low despite illness
•Should never replace clinical judgment
Tweet 7 (Special note for Rheumatology):
💡 In autoimmune & rheumatic diseases, PCT helps:
•Distinguish flare vs infection in patients on immunosuppressants
•Guide safe antibiotic use
But beware → high-dose steroids & biologics may blunt inflammatory markers.
Tweet 8 (Take-home):
Procalcitonin = 🧪 helpful tool, not a magic bullet.
Best used with clinical exam + other labs (CRP, cultures, imaging).
👉 It guides antibiotics, but doesn’t write the prescription for you.
#MedEd #Procalcitonin #Sepsis
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Tweet 1:
ANCA — one antibody, many confusions.
From GPA to drug-induced vasculitis, it’s powerful when used right…
and misleading when used wrong.
Here’s a quick guide 👇
@IhabFathiSulima @DrAkhilX @CelestinoGutirr #MedTwitter #Rheumatology
🧵 HLA-B27 in Rheumatology:
Tweet 1:
“HLA-B27 — a genetic marker with a powerful reputation.
From ankylosing spondylitis to reactive arthritis, it shapes how we think about SpA.
But what does a positive result really mean? 👇”
@IhabFathiSulima @DrAkhilX @CelestinoGutirr #MedTwitter #Rheumatology
Tweet 2 (What is HLA-B27?):
•Human Leukocyte Antigen, class I molecule
•Encoded on chromosome 6
•Important in antigen presentation
•Strong association with seronegative spondyloarthritis
Tweet 3 (Prevalence):
•General population: 6–8% (varies by ethnicity)
•AS patients: >90% positive
•But: Most HLA-B27+ people never develop disease
Tweet 1:
“C3 & C4: two small proteins, big role in lupus care.
But when are they truly helpful — and when do they mislead?
A quick guide to understanding complement in rheumatology 👇”
@IhabFathiSulima #MedTwitter #Rheumatology
Tweet 2 (Basics):
•Complement = part of innate immunity.
•C3 & C4 are the most commonly measured components.
•C3 = central to both classical & alternative pathways.
•C4 = mainly reflects the classical pathway.
Tweet 3 (Why do we check them?):
•Monitoring lupus activity (esp. nephritis).
•Evidence of ongoing immune complex consumption.
•Supportive for classification in SLE.
🧵 Anti-dsDNA:
Tweet 1:
“Anti-dsDNA positive” – one lab result that makes every rheumatologist think of lupus.
But how specific is it? How do we use it in practice? Here’s a breakdown 🧵 #Rheumatology #Lupus #MedTwitter
@IhabFathiSulima @DrAkhilX @CelestinoGutirr @Bealoquebea @Janetbirdope @Lupusreference
Tweet 2 (Basics):
🔹 Anti-dsDNA = autoantibody against native double-stranded DNA
•Present in ~60–70% of SLE patients
•Rare in healthy individuals
•Much more specific than ANA
Tweet 3 (Why important?):
✨ Clinical relevance:
•Diagnostic: Included in ACR/EULAR SLE criteria
•Prognostic: Associated with lupus nephritis & flares
•Monitoring: Levels often rise with disease activity
🧵 ANA by ELISA:
Tweet 1:
“ANA positive by ELISA” – a common lab report. But what does it really mean? How does it compare with the gold-standard ANA IFA? Let’s break it down 🧵 #Rheumatology #MedTwitter @ihabFathiSulima @DrAkhilX @CelestinoGutirr @Janetbirdope @RheumNow
Tweet 2 (Basics):
🔹 ANA ELISA = Enzyme-Linked Immunosorbent Assay
•Antigens (dsDNA, Sm, RNP, SSA, SSB, etc.) are coated on a plate
•Patient serum is added → antibodies bind → detected with enzyme reaction
✅ Automated
✅ Quantitative (gives titres/values)
Tweet 3 (Pros):
✨ Advantages of ANA ELISA:
•High-throughput (good for screening many samples)
•Less observer variability than IFA
•Can simultaneously detect multiple autoantigens
•Cost-effective & widely available
Tweet 1 (Intro)
🔹 Anti-CCP (Anti-Cyclic Citrullinated Peptide) antibodies are game-changers in diagnosing Rheumatoid Arthritis (RA).
More specific than RF and can even predict disease before symptoms appear!
Tweet 2 – What is Anti-CCP?
🔹 Autoantibody targeting citrullinated proteins (proteins where arginine is converted to citrulline).
🔹 Produced due to autoimmune response in RA.
🔹 Highly specific marker for RA (~95%).
Tweet 3 – Why citrullination matters
Citrullination → post-translational modification → proteins become immunogenic.
Immune system mistakes them as foreign → autoantibody formation → joint inflammation.