18 Sep 2020

8/6/20 AL Amyloidosis

At Goldstein Report, PGY3 Denna Lo presented a case of a 71 y/o M with no past medical history who presented with 10 months of bilateral LE swelling with acute worsening one day prior to admission (swelling from legs up to testicles). Reports associated poor PO intake, nausea and 20 pound weight loss for the past 3 months. Review of systems otherwise negative. SH only pertinent for being born in Mexico but has lived in the US for the past 25 years. No tobacco/ETOH/drug history. Vitals were significant for HR 88, RR 24, BP 77/57 (MAP 64) and satting 100% on RA. Exam showed a thin male, diminished breath sounds at b/l lung bases, 4+ b/l LE edema from feet up to mid thighs and 1+ b/l UE edema from hands to shoulders.

CBC: WBC 7.8 > Hb 16.1/Hct 48.3 <Plt 177
CMP:
Na 134/K 4.9/Cl 93/HCO3 29/BUN 19/Cr 0.98 <Glucose 93
ALP 246>T.protein 4.2/Albumin 1.9/AST 41/ALT 32/Tbili 0.8/DBili 0.4

DL1

Renal workup:

  • UA significant for protein >300, negative glucose, trace blood (11-25 RBC), negative leuks/nitrite, 1-4 fine granular casts, 11-20/LPF hyaline casts
  • Spot Uprotein 845 mg/dL; 24 hr Uprotein 4.86 g/24H
  • Ucr 93 mg/dL
  • FeNa 0.3%
  • FeUrea 18.6%
  • PLA2R negative

Heme workup:

  • SPEP: immunofixation reveals no definitive monoclonal protein bands
  • UPEP: no aberrant protein bands observed
  • Kappa LC 27.7, Lambda LC 153.6; K/L: 0.18 (normal 0.26-1.65)

Autoimmune workup:

  • ANA negative
  • C3 84 (normal 90-180)
  • C4 23.6 (normal 10-40)

Infectious workup:

  • BCx
  • HIV and RPR negative
  • Acute hepatitis panel negative
  • COVID-19 negative
  • Lactate 1.4
  • Procal 0.2 ng/mL

Cardiac workup:

  • Troponin 0.13 ng/mL > 0.13 ng/mL > 0.18 ng/mL
  • Pro-BNP 23939 pg/mL (normal <125)
  • EKG:

DL6

  • TTE showed mild concentric hypertrophy of the L ventricle with EF of 37%. Moderate diffuse hypokinesis and Grade II diastolic function. R ventricle systolic function is normal. Estimated peak pressure is 17 mmHg. No significant valvular disease.

Renal biopsy was performed with findings of amyloidosis, AL type, lambda restricted, involving the glomeruli, vessels and interstitium.

Treatment: Patient was started CyBorD (Cyclophosphamide-bortezomib-dexamethasone).

Take home points:

  1. Light-chain (AL) amyloidosis is the most common form of systemic amyloidosis, accounting for 70% of patients with amyloidosis. It is characterized by deposition of a misfolded monoclonal light chain that is secreted from a malignant plasma cell clone. Incidence is 9-14 cases/million person years.
  2. Most common symptoms are weight loss, fatigue, edema and dyspnea on exertion. Lightheadness and orthostatic syncope are rather frequent due to reduced intravascular volume due to hypoalbuminemia, use of diuretics and autonomic failure.
  3. Diagnosis requires presence of all 4 criteria:
    1. Presence of an amyloid related systemic syndrome
    2. Positive amyloid staining by Congo red in any tissue
    3. Evidence that amyloid is light chain related
    4. Evidence of a monoclonal plasma cell proliferative disorder (SPEP, UPEP, FLC ratio or BMBx)
  4. Treatment includes chemo (melphalan- or bortezomib-based) or autologous HSCT.

Sentinel Article:
Recent Advances in the Diagnosis, Risk Stratification and Management of Systemic Light-Chain Amyloidosis 

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.