Medical Forum

🔥 SYSTEMIC CONNECTIVE TISSUE DISEASES (SCTD) — NEET PG RAPID REVISION
📌 Most Important Antibodies & Associations
🔹 SLE ✅ Anti-dsDNA → Disease activity correlate
✅ Anti-Sm → Most specific
✅ Anti-Ro/SSA → Neonatal lupus, congenital heart block
✅ Anti-Ribosomal P → Neuropsychiatric SLE
💡 Malar rash + photosensitivity + nephritis = Think SLE
🔹 Rheumatoid Arthritis ✅ Anti-CCP → More specific than RF
✅ Correlates with disease activity
💡 MCP/PIP involvement + morning stiffness >1 hr
🔹 Mixed Connective Tissue Disease (MCTD) ✅ Anti-U1 RNP MUST for diagnosis
💡 Features overlap of: SLE + Scleroderma + Polymyositis
🔹 Sjogren Syndrome ✅ Anti-Ro/SSA & Anti-La/SSB
✅ Lip biopsy = confirmatory
💡 Dry eyes + dry mouth + parotid enlargement
🔹 Systemic Sclerosis ✅ Diffuse type → Anti-Scl-70
✅ Limited type (CREST) → Anti-centromere
💡 CREST = Calcinosis, Raynaud, Esophageal dysmotility, Sclerodactyly, Telangiectasia
🔹 Inflammatory Myositis ✅ Anti-Jo-1
💡 Mechanic’s hands + proximal muscle weakness
🔹 Important PYQ ⭐ Anti-dsDNA → best marker for SLE activity
⭐ Anti-Sm → most specific for SLE
⭐ Anti-CCP > RF specificity
⭐ Anti-centromere → CREST
⭐ Anti-Scl-70 → diffuse systemic sclerosis

🧬 HLA HIGH-YIELD ASSOCIATIONS — NEET PG
🔥 Important HLA Associations
✅ HLA-B27
➡ Ankylosing spondylitis
➡ Reactive arthritis
➡ Psoriatic arthritis
➡ Enteropathic arthritis
💡 “B27 = Seronegative spondyloarthropathy”
✅ HLA-DR3
➡ Type 1 DM
➡ SLE
➡ Graves disease
➡ Hashimoto thyroiditis
➡ Myasthenia gravis
✅ HLA-DR4
➡ Rheumatoid arthritis
➡ Type 1 DM
✅ HLA-DQ2 / DQ8
➡ Celiac disease
⭐ DQ2 more common
✅ HLA-B51
➡ Behçet disease
✅ HLA-DR2
➡ Multiple sclerosis
➡ Goodpasture syndrome
✅ HLA-B8
➡ Myasthenia gravis
🔥 Super PYQ Lines
⭐ HLA-B27 → Ankylosing spondylitis
⭐ HLA-DR4 → Rheumatoid arthritis
⭐ HLA-DQ2/DQ8 → Celiac disease
⭐ HLA-DR3 → Autoimmune diseases
💡 Remember: “B = Bone diseases” → B27
“DR = Autoimmune disorders”