Homology between TSH-R Tg TPO and Hashimoto rsquo s encephalopathy autoantigens

Abstract

Introduction 3. Materials and methods 4. Results 5. Discussion 6. Conclusion 7. References

Amino acid sequence homology between thyroid autoantigens and central nervous system proteins: Implications for the steroid-responsive encephalopathy associated with autoimmune thyroiditis

“…We used our standard procedure, as in previous bioinformatics papers [25] , [26] , [27] , [28] , [29] , [30] , [31] . We retrieved the amino acid sequence of the precursors of the three “classical” human thyroid autoantigens, i.e.…”

“…Proteins labeled as “incomplete” or “hypothetical” were excluded. We also excluded alpha-enolase, AKRIAI and DDAHI, since they were investigated in our previous paper [25] . The Protein BLAST (Basic Local Alignment Search Tool) software version 2.8.0+ [32] was used to perform the comparison.…”

“…Just very recently, we demonstrated that there is striking local homology between thyroid autoantigens and the three HE/SREAT-autoantigens [25] . Particularly, Tg was homologous to 10 regions of alpha-enolase, 8 regions of AKRIAI, and 5 regions of DDAHI.…”

“…From the opposite perspective, a total of 4 regions of Tg, 5 of TPO and 2 of TSH-R homologous to alpha-enolase contained epitopes. Epitopes in each of the three thyroid autoantigens were present also in their regions that were homologous to regions of AKRIAI and DDAHI [25] . In brief, we provided some indirect evidence that a number of regions of homologies were relevant for the autoimmunity associated with HE/SREAT.…”

Non-Conventional Clinical Uses of TSH Receptor Antibodies: The Case of Chronic Autoimmune Thyroiditis

“…In a very unusual scenario CAT is associated with encephalopathy and this association, later defined "steroidresponsive encephalopathy associated with autoimmune thyroiditis (SREAT)" (48) has been described for the first time in 1966 (49). A serological distinctive feature of the disease is the contemporary presence of one or more thyroid antibodies (TgAb, TPOAb and TRAb) and antibodies against brainexpressed autoantigens; amongst the latter anti-alpha-enolase antibodies are the most frequent (50). Interestingly a recent study (50) has shown homologies between TSH-R and alpha-enolase; keeping in mind that main thyroid antigens (Tg, TPO and TSHr) are also expressed in the central nervous system and that alphaenolase is expressed also in the thyroid, a pathogenic contribution of TRAb might be speculated.…”