IgG4 and Lactoferrin (ALF) autoantibodies (Ab) prevalence in different duration type 1 diabetes mellitus (T1D).
A total of 78 patients (41 men, 37 women) with T1D were included in the study. Patients were divided in 2 groups, according to T1D duration. All patients underwent an immunological study, which included the determination of IgG4 and ALF Ab.The patients were also examined for pancreatic b-cell Aab, C-peptide, HbA1c. Ab to IgG4, ALF, glutamic acid decarboxylase (GADA), tyrosine phosphatase-like IA-2 (IA-2A) and zinc T8 (ZnT8A) were detected by ELISA.
| T1D groups | a (n=32) | b (n=46) |
|---|---|---|
| Age, years | 22,3 [19,2;25,8] | 29,7 [24,6;39,1] |
| T1D duration, years | 2,7 [0,8;3,9] | 17,6 [14,4;21,3] |
| Fasting C-peptide, ng/ml | 0,86 [0,53;1,4] | 0,01 [0,01;0,01] |
| HbA1C, % | 8,7 [7,4;11,3] | 8,2 [7,1;9,9] |
| IgG4 Ab, μg/ml | 685,5 [418,1;1301,4]. | 987,1 [536,2;2127,3] |
| ALF, U/ml | 1,6 [0,8;1,1] | 1,7 [1,2;1;9] |
Table 1. Patients characteristics
| Ab, U/ml | a (n=21) | b (n=15) |
|---|---|---|
| ZnT8A | 219,7 [79,1;326,3] | 67,3 [16,9;139,5] |
| IA-2A | 233,5 [194,2;366,2] | 39,9 [13,5;115,3] |
| GADA | 384,4 [13,2;1526,1] | 23,5 [5,2;27,0] |
Table 2. Pancreatic β-cell Ab positive titres
All of 78 patients with T1D were negative for ALF Aab. In group "a" all patients were negative for IgG4 and in group "b" 3 (6,5%) were positive (Aab levels – 4897,2; 3813,7; 3479,6). We didn't find association between IgG4, ALF levels and HbA1C, fasting c-peptide and b-cell Ab p<0,05. Patients in group "b" had higher IgG4 and ALF than in group "a", p<0,05.
The present data didn’t confirm the high presence of IgG4 and ALF in T1D, but higher Ab levels was found in long-standing T1D.