**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Pedro A. Laires, Alexion–AstraZeneca Rare Disease, Barcelona, Spain

**Main Body of the Abstract**
OBJECTIVES:
This study investigated subtype distribution of amyloidosis, a rare disease, specifically light-chain amyloidosis (AL) and transthyretin amyloidosis (ATTR). The distribution of the two forms of ATTR, wild-type [ATTRwt] and variant [ATTRv], and its phenotypes was also evaluated.
METHODS:
A cross-sectional analysis was conducted using an anonymized dataset from TriNetX Dataworks, USA Network, an electronic health records database of approximately 95 million patients from 57 USA healthcare organizations. Adults diagnosed with amyloidosis between 01/01/2021-12/31/2021 and with ≥2 records for amyloidosis ≥30 days apart were included. Subtypes and phenotypes of amyloidosis ascertained by ICD-10 coding system.
RESULTS:
5575 amyloidosis cases were analysed with 30% (N=1,671) and 4% (N=218) classified as AL and ATTR, respectively. Other types accounted for 44% of cases (N=2,433) and the remaining 22% (N=1,253) as unspecified amyloidosis. Within ATTR, ATTRwt and ATTRv constituted 45% (N=99) and 55% (N=119) of cases, respectively. Phenotypic manifestations of ATTR were as follows: cardiac-only 28% (N=60); neuropathic-only 36% (N=78); concomitant cardiac and neuropathic 16% (N=34). Among ATTRwt, phenotype was as follows: cardiac-only 52%; neuropathic-only 8%; concomitant cardiac and neuropathic 15%. Among ATTRv cases: cardiac-only 8%; neuropathic-only 59%, concomitant cardiac and neuropathic 16%.
CONCLUSION:
Our results demonstrate that the commonest subtypes of amyloidosis (ATTR and AL) were surprisingly underrepresented, particularly ATTRwt. These findings reveal a pressing need for appropriate coding to reflect amyloidosis subtype classification in order to foster real-world research in amyloidosis, so that we may develop our understanding of this rare disease and improve treatment and outcomes.



**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
_Pedro A. Laires, Alexion–AstraZeneca Rare Disease, Barcelona, Spain_

**Main Body of the Abstract**
**OBJECTIVES:**
This study investigated subtype distribution of amyloidosis, a rare disease, specifically light-chain amyloidosis (AL) and transthyretin amyloidosis (ATTR). The distribution of the two forms of ATTR, wild-type [ATTRwt] and variant [ATTRv], and its phenotypes was also evaluated.
**METHODS**:
A cross-sectional analysis was conducted using an anonymized dataset from TriNetX Dataworks, USA Network, an electronic health records database of approximately 95 million patients from 57 USA healthcare organizations. Adults diagnosed with amyloidosis between 01/01/2021-12/31/2021 and with ≥2 records for amyloidosis ≥30 days apart were included. Subtypes and phenotypes of amyloidosis ascertained by ICD-10 coding system.
**RESULTS**:
5575 amyloidosis cases were analysed with 30% (N=1,671) and 4% (N=218) classified as AL and ATTR, respectively. Other types accounted for 44% of cases (N=2,433) and the remaining 22% (N=1,253) as unspecified amyloidosis. Within ATTR, ATTRwt and ATTRv constituted 45% (N=99) and 55% (N=119) of cases, respectively. Phenotypic manifestations of ATTR were as follows: cardiac-only 28% (N=60); neuropathic-only 36% (N=78); concomitant cardiac and neuropathic 16% (N=34). Among ATTRwt, phenotype was as follows: cardiac-only 52%; neuropathic-only 8%; concomitant cardiac and neuropathic 15%. Among ATTRv cases: cardiac-only 8%; neuropathic-only 59%, concomitant cardiac and neuropathic 16%.
**CONCLUSION**:
Our results demonstrate that the commonest subtypes of amyloidosis (ATTR and AL) were surprisingly underrepresented, particularly ATTRwt. These findings reveal a pressing need for appropriate coding to reflect amyloidosis subtype classification in order to foster real-world research in amyloidosis, so that we may develop our understanding of this rare disease and improve treatment and outcomes.



Subtype distribution of amyloidosis in the united states: insights from an electronic health records database analysis PB59 (#112)

We invite you to attend the XIX International Symposium on Amyloidosis to be held in Rochester, MN.

This symposium is organized as a hybrid meeting (with the focus on in-person) held from Sunday, May 26 through Thursday, May 30, 2024.

Together with the ISA Board and members of Mayo Clinic, a very attractive scientific hybrid program is being planned. The program will cover a variety of types of systemic amyloidosis: ATTR (hereditary and wild-type), AL (light-chain), AA and less frequent forms. There will be key lectures, specific symposia including those company sponsored, oral presentations and poster sessions of accepted abstracts.

COURSE DESCRIPTION
This program will provide a comprehensive review of state-of-the-art education in systemic amyloidosis: basic science, pathophysiology, diagnosis, current and emerging treatments. Scientific presentations will include competitive oral and poster abstracts. The rapid evolution of scientific discovery and expanding treatment options has created tremendous interest in the field and this meeting will fill and important gap in educating scientists and clinicians.