Racial and ethnic disparities in early mortality among patients with inborn errors of immunity

Diagnostic disparities in inborn errors of immunity: From clinical suspicion to diagnosis

Background

Emerging evidence suggests that inborn errors of immunity (IEI) are underdiagnosed among underserved populations. However, there remains a lack of national studies evaluating diagnostic disparities in IEI.

Objective

We examined disparities in the timely IEI diagnosis and related health outcomes.

Methods

A retrospective analysis was performed of a US national claims database (years 2007 to 2021). Participants included patients diagnosed with an "unspecified immune deficiency" (uID) and presented with IEI-related symptoms, who later received an IEI diagnosis (n = 1429). We quantified the diagnostic interval from clinical suspicion (uID) to IEI diagnosis and examined its association with sociodemographic factors and related health outcomes.

Results

The median (interquartile range) diagnostic interval was 369 (126-808) days. Diagnostic interval was 14% longer among patients residing in predominantly non-White neighborhoods, compared with those in predominantly White neighborhoods (P = .04), despite having more severe IEI-related symptoms at uID diagnosis and significantly more health care encounters for pneumonia (incidence rate ratio, 2.24; 95% confidence interval, 1.40-3.70) and sepsis (incidence rate ratio, 2.15; 95% confidence interval, 1.21-3.99) in the year after uID diagnosis. Residence in neighborhoods with greater deprivation was also associated with more severe IEI-related symptoms and greater health care utilization in the year after uID diagnosis. Older age was associated with longer diagnostic interval (P < .001). Longer diagnostic interval was associated with a longer interval to receiving IgR therapy (hazard ratio, 0.64; 95% confidence interval, 0.49-0.83).

Conclusion

We observed significant racial and socioeconomic disparities in the timeliness of IEI diagnosis and IEI-related outcomes. Further studies are needed to address the underlying factors contributing to diagnostic inequity.

Update on inborn errors of immunity

Ever since the first description of an inherited immunodeficiency in 1952 in a boy with gammaglobulin deficiency, new insights have progressed rapidly in disorders that are now referred to as inborn errors of immunity. In a field where fundamental molecular biology, genetics, immune signaling, and clinical care are tightly intertwined, 2022-24 saw a multitude of advances. Here we report a selection of research updates with a main focus on (1) diagnosis and screening, (2) new genetic defects, (3) susceptibility to severe coronavirus disease 2019 infection and impact of vaccination, and (4) treatment. Importantly, new pathogenic insights more rapidly affect treatment outcomes, either through an earlier and more precise diagnosis or through implementation of novel, personalized treatment. The field is growing rapidly, so awareness, communication, and collaboration are key to improving treatment outcomes.

Evaluating large language model performance to support the diagnosis and management of patients with primary immune disorders

BACKGROUND

Generative artificial intelligence (GAI) is transforming health care in a variety of ways; however, the present utility of GAI for supporting clinicians who treat rare disease such as primary immune disorders (PIs) is not well studied. We evaluated the ability of 6 state-of-the-art large language models (LLMs) for providing clinical guidance about PIs.

OBJECTIVE

To quantitatively and qualitatively measure the utility of current, open-source LLMs for diagnosing and providing helpful clinical decision support about PIs.

METHODS

Five expert clinical immunologists each provided 5 real-world, anonymized PI case vignettes via multi-turn prompting to 6 LLMs (OpenAI GPT-4o, Llama-3.1-8B-Instruct, Llama-3.1-70B-Instruct, Mistral-7B-Instruct-v0.3, Mistral-Large-Instruct-2407, Mixtral-8x7B-Instruct-v0.1). We assessed the diagnostic accuracy of the LLMs and the quality of clinical reasoning using the Revised-IDEA (R-IDEA) score. Qualitative LLM assessment was made by immunologist narratives.

RESULTS

Performance accuracy (>88%) and R-IDEA scores (≥8) were superior for 3 models (GPT-4o, Llama-3.1-70B-Instruct, Mistral-Large-Instruct-2407), with GPT-4o achieving the highest diagnostic accuracy (96.2%). Conversely, the remaining 3 models fell below acceptable accuracy rates near 60% or lower and had poor R-IDEA scores (≤0.55), with Mistral-7B-Instruct-v0.3 attaining the worst diagnostic accuracy (42.3%). Compared with the 3 best-performing LLMs, the 3 worst-performing LLMs had a substantially lower median R-IDEA score (P < .001). Interclass correlation coefficient for R-IDEA score assignments varied substantially by LLM, ranging from good to poor agreement, and did not appear to correlate with either diagnostic accuracy or median R-IDEA score. Qualitatively, immunologists identified several themes (eg, correctness, differential diagnosis appropriateness, relative conciseness of explanations) of relevance to PIs.

CONCLUSIONS

LLM can support diagnosis and management of PIs; however, further tuning is needed to optimize LLMs for best practice recommendations.

Disparities in Genetic Testing for Inborn Errors of Immunity

BACKGROUND

Inequities in genetic testing have been documented in a range of diseases, and no-charge genetic testing programs have been proposed as a means to enhance access. However, no studies have examined disparities in genetic testing for inborn errors of immunity (IEI) and the impact of no-charge programs on testing equity.

OBJECTIVE

To examine socioeconomic, geographic, and racial disparities in the uptake of genetic testing for IEI in the United States and the impact of a no-charge sponsored program on testing equity.

METHODS

This was a retrospective cohort analysis of (1) a national claims database capturing individuals with IEI (n = 18,603), and (2) data from a clinical genetic testing laboratory capturing patients with IEI participating in a no-charge sponsored program (n = 6,681) and a non-sponsored program (n = 29,579) for IEI genetic testing.

RESULTS

Among patients with IEI captured in the claims database, those residing in areas of greater deprivation (odds ratio [OR] = 0.95; 95% CI, 0.92-0.98), rural areas (OR = 0.82; 95% CI, 0.71-0.96), and non-White neighborhoods (OR = 0.89, 95% CI 0.81-0.98) were less likely to undergo genetic testing. Participants in the sponsored IEI genetic testing program lived in areas of greater deprivation compared with the non-sponsored program (median, 46 vs 42; P < .001). However, historically excluded racial groups were underrepresented in both the sponsored and non-sponsored programs relative to disease burden.

CONCLUSIONS

We found significant disparities in genetic testing for IEI. Although eliminating the financial barriers to testing reduced socioeconomic disparities in genetic testing for IEI, racial disparities persisted. Further research is needed to address barriers to testing among underserved populations.

Hematopoietic cell transplantation for inborn errors of immunity: an update on approaches, outcomes and innovations

PURPOSE OF REVIEW

Allogeneic hematopoietic cell transplantation (HCT) is a curative option for many for inborn errors of immunity (IEI). This review highlights recent progress in the field of HCT for IEI.

RECENT FINDINGS

Alternative donor transplantation continues to expand donor options for patients with IEI. Reduced intensity and reduced toxicity conditioning approaches are being investigated and optimized. Immunomodulatory bridging therapies are yielding impressive progress in outcomes for primary immune regulatory disorders (PIRD) but require further study in prospective trials. Single-institution, multicenter and consortium studies have improved our understanding of factors that affect overall outcomes in IEI and outcomes in Wiskott-Aldrich syndrome (WAS), chronic granulomatous disease (CGD) and PIRD in particular. Data show that second HCT offers a viable chance of cure to some IEI patients. Late effects in IEI HCT survivors are being better characterized. Preclinical studies of chemo(radiation)-free HCT strategies hold promise for decreasing HCT toxicity.

SUMMARY

Improvements in our understanding of HCT donor choice, conditioning regimen, immunomodulatory bridging therapies, diagnostic and post-HCT surveillance testing and late effects continue to yield advancements in the field of HCT for IEI.

Universal Exome Sequencing in Critically Ill Adults: A Diagnostic Yield of 25% and Race-Based Disparities in Access to Genetic Testing

Numerous studies have underscored the diagnostic and therapeutic potential of exome or genome sequencing in critically ill pediatric populations. However, an equivalent investigation in critically ill adults remains conspicuously absent. We retrospectively analyzed whole exome sequencing (WES) data available through the PennMedicine Biobank (PMBB) from all 365 young adult patients, aged 18-40 years, with intensive care unit (ICU) admissions at the University of Pennsylvania Health System who met inclusion criteria for our study. For each participant, two Medical Genetics and Internal Medicine-trained clinicians reviewed WES reports and patient charts for variant classification, result interpretation, and identification of genetic diagnoses related to their critical illness. Of the 365 individuals in our study, 90 (24.7%) were found to have clearly diagnostic results on WES; an additional 40 (11.0%) had a suspicious variant of uncertain significance (VUS) identified; and an additional 16 (4.4%) had a medically actionable incidental finding. The diagnostic rate of exome sequencing did not decrease with increasing patient age. Affected genes were primarily involved in cardiac function (18.8%), vascular health (16.7%), cancer (16.7%), and pulmonary disease (11.5%). Only half of all diagnostic findings were known and documented in the patient chart at the time of ICU admission. Significant disparities emerged in subgroup analysis by EHR-reported race, with genetic diagnoses known/documented for 63.5% of White patients at the time of ICU admission but only for 28.6% of Black or Hispanic patients. There was a trend towards patients with undocumented genetic diagnoses having a 66% increased mortality rate, making these race-based disparities in genetic diagnosis even more concerning. Altogether, universal exome sequencing in ICU-admitted adult patients was found to yield a new definitive diagnosis in 11.2% of patients. Of these diagnoses, 76.6% conferred specific care-altering medical management recommendations. Our study suggests that the diagnostic utility of exome sequencing in critically ill young adults is similar to that observed in neonatal and pediatric populations and is age-independent. The high diagnostic rate and striking race-based disparities we find in genetic diagnoses argue for broad and universal approaches to genetic testing for critically ill adults. The widespread implementation of comprehensive genetic sequencing in the adult population promises to enhance medical care for all individuals and holds the potential to rectify disparities in genetic testing referrals, ultimately promoting more equitable healthcare delivery.