Narges presented a case of an elderly lady with chronic total body pain, found to have rheumatoid arthritis, pancytopenia, and splenomegaly… What could this be? Classic triad for Felty’s Syndrome!

We will start with a brief review of RA:

Rheumatoid Arthritis

• Epidemiology
  • F : M = 3:1
  • Age of onset usually 50-75
  • Risk factors
    • Smoking
    • Nulliparity
    • Genetics (twins)
  • Extra-articular manifestation (40% cases will have some degree of involvement)
    • Bone: Osteoporosis, esp hip and L-spine
    • MSK: Myositis, muscle weakness
    • Vessels: Vasculitis
      • Neuropathy, pain (MSK vessel inflammation), skin ulceration
    • Skin: Rheumatoid nodule, skin ulcers esp LE, neutrophilic dermatoses
    • Eye: Episcleritis, scleritis, rare
    • Lung: Rheumatoid nodules, parenchymal disease, pleural disease, airway obstruction, pleural effusions (low glucose < 30)
    • Heart: Inc risk of CAD
    • Neuro: Inc risk for stroke
    • Kidney: Higher risk for development of rneal disease
    • Heme: Anemia, neutropenia, thrombocytopenia, inc risk of lymphoma
  • Diagnosis
    • Inflammatory arthritis 3 or more joints
    • RF or CCP
    • ESR/CRP elevation
    • > 6 weeks sx
  • Immunology
    • RF: Sensitivity 80%, Specificity 87%. 5-10% of healthy individuals might have positivity
    • CCP: Sensitivity 76%, Specificity 96%
  • Management (per American College of Rheumatology)
    • Treat ASAP, usually start with DMARD: Screen for latent TB, HBV and HCV prior!
    • HCQ (hydroxychloroquine): Baseline retinal screening and then annual after 5 years of use
    • SSZ (sulfasalazine)
    • MTX (methotrexate)
    • LEF (Leflunomide)
      • Mono
      • Double
      • Triple
      • Combo
    • Biologics
      • Tofacitinib (Janus kinase inhibitor)
      • Abatacept (T-lymphocyte inhibitor)
      • Tocilizumab (IL6 Ab)
      • Rituximab (CD20 MAB)
      • TNF: Etanercept, influximab
    • Steroids

Felty’s Syndrome

• Epidemiology:
  • Occurs in ~ 1% of patients with RA
  • Not very well understood
  • Associated with HLA-DR4
• Presentation: Triad of RA, pan-cytopenia, and splenomegaly
  • RA: Typically more severe, erosive, seropositive for RF +/- CP
    • More frequently with extra-articular manifestations
  • Neutropenia: Present in 100%, ANC < 2000 typically, usually with associated anemia + thrombocytopenia. Typically persistent
  • Splenomegaly: Present in most but does not correlate with disease severity
  • Inc risk for hematologic malignancy
• Diagnosis
  • Clinical: Triad of RA, neutropenia, and splenomegaly
  • Immune: + DsDNA, anti-glucose 6 phosphate isomerase (92%), might have circulating immune complex formation (low complements)

If BM biopsy with lymphocyte infiltration = Large Granular Lymphocyte Syndrome (Pseudo-Felty’s), frequent infections, can progress to LGL Leukemia