Table I.

Follow-up information of blood donors with M-protein in their sera.

All cases of MG n=104
Median follow up	92 months
Median age (range) at the end of follow up	60 years (36–74)
Alive at the end of follow up (%)	102 (98%)
Transient MG n=14
Median age (range) at diagnosis	54 (30–66)
Ig subtype	IgG 13/IgM 1
Median M-protein concentration (range)	0.1 g/dL (0.1–0.4)
Detection at first test	3/14 (21%)
Early detected* MG-related diseases n=2 Smouldering MM
Ig Subtype	IgA, IgG
Age at diagnosis	57–60
Concentration of M-protein	N.A.
Detection at first test	2/2
MGUS n. 88
No evidence of MG-related disease	86
Occurrence of MG-related malignancy	1 (lymphoma)
Occurrence of other MG-related disease	1 (light chain deposition nephropathy)
Median age (range) at diagnosis	53 (28–67)
Ig Subtype	IgG 60 (69%)
	IgM 15 (17.2%)
	IgA11 (12.6%)
	IgD 1 (1%)
Median M-protein concentration at diagnosis (range)	0.2 g/dL (0.1–1.4)
Median M-protein concentration at the end of follow-up (range)	0.4 g/dL (0.1–2.5)
Detection at first test	55/88 (63.2%)
Cumulative person-years of observation	648

Legend: MG: monoclonal gammopathy;

^*Early detected MG-related diseases are considered those occurring during the follow-up within 12 months of the first detection of MG.