🧬 SPEP — Serum Protein Electrophoresis Interpreter
Convert SPEP fractions (%) to absolute values (g/dL) and screen for classic patterns.
For reference only — Definitive interpretation requires a clinical pathologist or hematologist. M-spikes must be confirmed with immunofixation electrophoresis (IFE) and serum free light chains.
Normal: 6.0–8.3 g/dL
Electrophoresis Fractions (%)
Normal 55.8–66.1%
Normal 2.9–4.9%
Normal 7.1–11.8%
Normal 8.4–13.1%
Normal 11.1–18.8%
SPEP Reference Ranges
| Fraction | % of Total | Absolute (g/dL) | Major Proteins |
|---|---|---|---|
| Albumin | 55.8–66.1 | 3.5–5.5 | Albumin |
| Alpha-1 | 2.9–4.9 | 0.2–0.4 | α1-antitrypsin (AAT), α1-acid glycoprotein, HDL |
| Alpha-2 | 7.1–11.8 | 0.5–0.9 | Haptoglobin, ceruloplasmin, α2-macroglobulin |
| Beta | 8.4–13.1 | 0.6–1.1 | Transferrin, C3 complement, LDL |
| Gamma | 11.1–18.8 | 0.7–1.6 | IgG, IgA, IgM, IgD, IgE |
Key Pattern Guide
🔴 M-spike (Monoclonal Gammopathy)
Sharp peak in γ or β region. Differential: multiple myeloma, MGUS, smoldering myeloma, Waldenström macroglobulinemia, AL amyloidosis. Confirm with IFE.
🟠 Polyclonal Hypergammaglobulinemia
Broad-based γ elevation. Causes: chronic infection, cirrhosis, autoimmune disease, HIV, chronic inflammation.
🔵 Hypogammaglobulinemia
Decreased γ. Primary immunodeficiency (CVID, XLA), secondary from CLL/lymphoma therapy, or protein loss (nephrotic syndrome, PLE).
🟢 Acute-Phase Response
↑ α1 (AAT) and α2 (haptoglobin) with ↓ albumin. Seen in acute infection, trauma, surgery, malignancy.
🟣 Cirrhosis Pattern
↓ Albumin + β–γ bridging (IgA elevation obliterates the boundary between β and γ). Strong clue to chronic liver disease.
🩵 Nephrotic Syndrome Pattern
↓↓ Albumin + ↑ α2 (compensatory haptoglobin / α2-macroglobulin) + ↓ γ (urinary Ig loss).
Related Calculators
Disclaimer
Reference ranges vary by platform and laboratory; absolute values above are representative. Pattern recognition by a clinical pathologist or hematologist is required. M-spikes must be confirmed by immunofixation electrophoresis (IFE), serum free light chains (sFLC), and quantitative immunoglobulins.
References: O'Connell TX et al. Understanding and interpreting serum protein electrophoresis. Am Fam Physician. 2005. · Kyle RA et al. Prevalence of MGUS. NEJM. 2006.
Reference ranges vary by platform and laboratory; absolute values above are representative. Pattern recognition by a clinical pathologist or hematologist is required. M-spikes must be confirmed by immunofixation electrophoresis (IFE), serum free light chains (sFLC), and quantitative immunoglobulins.
References: O'Connell TX et al. Understanding and interpreting serum protein electrophoresis. Am Fam Physician. 2005. · Kyle RA et al. Prevalence of MGUS. NEJM. 2006.