Author Of 2 Presentations
P0304 - Can the induction of thyroid autoimmune antibodies after alemtuzumab treatment predict secondary autoimmune thyroid disorder? (ID 663)
Abstract
Background
Alemtuzumab (ALZ) belongs to the immune reconstitution therapies for relapsing-remitting multiple sclerosis (RRMS). ALZ therapy is associated with an increased risk for secondary autoimmune diseases (SAD), in particular autoimmune thyroid disorders (AITD).
Objectives
To investigate if the occurrence of thyroid auto-antibodies (Ab), after initiating ALZ treatment, could predict the development of AITD.
Methods
All RRMS patients in Sweden initiating ALZ (n=124, 74 females) 2014-2019, were consecutively included in this prospective observational study. Plasma samples were obtained prior to ALZ and at 6, 12 and 24 months of follow-up for analyses of thyroglobulin Ab (TgAb), thyroperoxidase Ab (TPOAb) and thyrotropin receptor Ab (TRAb). Monthly serum samples for free thyroxin and thyroid stimulating hormone, as well as clinical symptoms were followed to detect AITD.
Results
At mean follow-up of 4.5 (SD 1.6) years 50 patients (40%) had developed AITD (43 Graves’ disease). Mean time from baseline to AITD was 2.1 (SD 1.6) years, in 62 % the development of thyroid Ab preceded AITD. At baseline 5% (n=6/114) patients had positive TRAb, 3% (n=3/115) positive TgAb, and 3% (n=3/115) positive TPOAb. Corresponding values at 6 months were 3% (n=2/78), 6% (n=5/85), 5% (n=4/86), at 12 months 14% (n=14/102), 15% (n=15/102), 18% (n=18/102), and at 24 months 22% (n=16/73), 19% (n=15/78), 23% (n=18/78). No treatment was given for AITD in 4% (n=2/50), 14% (n=7/50) had levothyroxine (L-T4) only, 36% (n=18/50) high dose anti-thyroid drug (ATD) with L-T4, 34% (n=17/50) thyroidectomy, 4% (n=2/50) ATD alone, 2% (n=1/50) radioactive iodine and for 6% (n=3/50) data were missing. Mean time from detection of auto-Ab to diagnosis of AITD was 4 (SD 11.3) months. At baseline 9 patients had thyroid Ab, but only those with TRAb (n=3) developed AITD. The OR for AITD was 1.51 given TRAb compared to those with no TRAb at baseline. At 24 months, 27 patients were positive for either of the thyroid Ab, 93% (25/27) of these developed AITD. In contrast, only, 30% (15/51) of those thyroid Ab negative developed AITD (p<0.0001 x2- test).
Conclusions
AITD was developed in 40% of ALZ treated patients, at 24 months 21% had AITD which was similar with that reported from the pivotal studies of ALZ. Thyroid Ab preceded AITD in 62 % of cases. In contrast, the risk of AITD was low in cases without thyroid Ab. Although, monitoring thyroid Ab may be useful identifying patients at high risk for AITD, this has not so far had any therapeutic incentives.
P0361 - Non-thyroid secondary autoimmune diseases after alemtuzumab treatment: real-world data from a nationwide prospective observational cohort in Sweden. (ID 664)
Abstract
Background
Alemtuzumab (ALZ) belongs to the immune reconstitution therapies for relapsing-remitting multiple sclerosis (RRMS). ALZ therapy is associated with an increased risk for secondary autoimmune diseases (SAD), in particular autoimmune thyroid disorders (AITD), but there are also an association to increased risk of immune mediated thrombocytopenic purpura (ITP) and other rare autoimmune disorders.
Objectives
To investigate the occurrence of SAD, other than AITD, and if auto-antibodies (Ab) could predict the development of non-thyroid SAD (NTSAD).
Methods
All RRMS patients in Sweden initiating ALZ (n=124, 74 females) 2014-2019, were consecutively included in this prospective observational study. Plasma samples were obtained prior to ALZ and at 6, 12 and 24 months of follow-up for analyses of glutamic acid decarboxylase Ab (GADAb), antinuclear Ab (ANA), smooth muscle Ab (SMA), antimitochondrial Ab (AMA) and anti-glomerular basement membrane Ab (GBMAb). Monthly blood and urine tests, as well as clinical symptoms, were followed to detect NTSAD.
Results
At mean follow-up of 4.5 (SD 1.6) years 8 patients (6.5%) had developed NTSAD; 5 ITP (4%), 2 neutropenia (2%), and 1 warm antibody haemolytic anaemia (1%). Mean time from baseline to respective NTSAD was 2.1 (SD 1.7) years, 0.6 (SD 0.7) years, and 5.5 years. At their diagnoses positive auto-Ab against platelets, neutrophils and erythrocytes, were present in 1, 0 and 1 ALZ treated patient respectively. No treatment was given for ITP in 3, 1 had intravenous immunoglobulin, romiplostim, corticosteroids, 1 had platelet transfusion, corticosteroids. 1 with neutropenia had granulocyte-colony stimulating factor. No treatment was given for the case with haemolytic anaemia. At baseline 1% (n=1/115) had positive GADAb, 12% (n=13/112) positive ANA, 4% (n=5/112) positive SMA, 0% (n=0/112) positive AMA and 3% (n=3/115) positive GBMAb. Besides these, the number of patients who at least once during the follow-up were positive for the auto-Ab that we regulatory checked for was as follows; 1% (n=1/124) GADAb, 10% (n=13/124) ANA, 3% (n=4/124) SMA, 0% (n=0/124) AMA and 0% (n=0/124) GBMAb, none of these developed any associated NTSAD.
Conclusions
In this real-world cohort study the occurrence of NTSAD, after ALZ treatment, was mainly hematologic, most frequent ITP (4%) and the majority required no treatment. Although the occurrence of auto-Ab was slightly more common after ALZ, compared to the general population, no corresponding NTSAD was found. This was in contrast to thyroid auto-Ab which often precede thyroid disease.