Levitz, David

Abstract Introduction: The Duffy null variant (genotype or phenotype) is associated with lower circulating absolute neutrophil counts (ANC) without increased risk for infection. It is found in ~66% of people identifying as Black or African American vs <1% of people of Asian or European ancestry. Many ANC reference intervals (RI) are not representative of the Duffy null population. There are no adult Duffy null WBC RI and no pediatric Duffy null ANC or WBC RI. Thus, we aimed to assess Duffy null ANC and WBC distributions as well as develop WBC and ANC RI for adults and pediatrics. Methods: Twenty-three sites across the United States collected samples with all sites excluding participants with conditions or medications that could impact ANC or WBC. Only Duffy null participants were included. Sex, race, ethnicity, age, sample collection type, practice setting, Duffy testing method, ANC, and WBC were recorded. The non-parametric method for determining lower limit of normal (LLN), upper limit of normal (ULN), and 90% confidence intervals (CI) around the limits was performed according to the Clinical and Laboratory Standards Institute guidelines. Specific ULN and LLN are not reported as these are preliminary data. The Mann-Whitney U test was used to compare sex and prior data; differences by age groups were assessed with Kruskal-Wallis test. Results: 316 participants 18+ years-old (y/o) were assessed of whom 62.3% (n=197) are female, 97.5% (n=308) identified as Black or African American, and 94.9% (n=300) identified as non-Hispanic. Median age was 47 y/o (IQR: 32-60.5). Median ANC was 2600/uL (IQR: 1860-3530; range: 400-7400); 28.6% (n=90) of participants had ANC <2000/uL, 13.6% (n=43) had ANC <1500/uL, and 2.5% (n=8) had <1000/uL. The 90% CI around the LLN was 810-1070/uL and 5570-7130/uL around the ULN. Consistent with prior data, there was a difference in median ANC by sex (male: 2400/uL; female: 2710/uL; p=0.02). There was no significant difference between this ANC data and previously published Duffy null ANC data (p=0.28). Median WBC was 5.4x109/L (IQR: 4.4-6.5; range: 2.10-11.64) with 4.1% (n=13) of participants with WBC <3.0x109/L. The 90% CI around the LLN is 3.68-4.30x109/L and 11.02-12.97x109/L around the ULN. 515 participants between 0-17 y/o were assessed with 51.8% (n=267) females, 94.8% (n=488) identified as Black or African American, and 94.0% (n=484) identified as non-Hispanic. Among pediatric participants, 56.8% (n=291) had ANC <2000/uL, 38.7% (n=198) had ANC <1500/uL, and 14.4% (n=74) had ANC <1000/uL. For those <1 y/o (n=29), median ANC was 950/uL (IQR: 840-1360; range: 111-3910). There are currently too few samples to predict ULN and LLN. Median WBC was 8.85x109/L (IQR: 7.03-10.16; range: 4.17-13.53). For those 1-5 y/o (n=143), median ANC was 1735/uL (IQR: 1100-2550; range: 207-5810) with a 90% CI around the LLN of 207-820/uL and 4020-5810/uL around the ULN. Median WBC was 6.72x109/L (IQR: 5.64-8.25; range: 3.68-12.97). For those 6-11 y/o (n=128), median ANC was 1590/uL (IQR: 1090-2470; range: 420-5490) with a 90% CI around the LLN of 420-910/uL and 4340-5490/uL around the ULN. Median WBC was 5.42x109/L (IQR: 4.45-6.70; range: 2.80-10.50). For those 12-17 y/o (n=215), median ANC was 2190/uL (IQR: 1460-2930; range: 204-5850) with a 90% CI around the LLN of 540-930/uL and 4350-5510/uL around the ULN. Median WBC was 5.06x109/L (IQR: 4.26-6.20; range of 2.04-9.91). There is a significant difference in ANC by age category (p<0.0001). Conclusion: This is the first report of healthy pediatric Duffy null ANC and WBC data and the first large-scale verification of adult Duffy null ANC and WBC data. Final RI are expected in September 2025. Among adults with the Duffy null phenotype, ANC LLN are likely between 810-1070/uL. Pediatric ANC LLN are likely as low as 207-820/uL (1-5 y/o), 420-910/uL (6-11 y/o), and 540-930/uL (12-17 y/o). These findings redefine “normal” as a significant proportion of healthy participants have ANC or WBC below current RI or below thresholds typically defined as disease. Limitations include heterogeneous sample populations and collection methods. Future analyses will assess differences between collection sites or methods. Ultimately, this work lays the foundation for a more scientifically sound and equitable approach to medical care by ensuring that RI accurately reflects health for the entire community. Healthcare systems are strongly encouraged to adopt Duffy null-specific ANC and WBC RI.

Background: Recent advancements in multiple myeloma (MM) diagnosis and treatment significantly improved patients' survival and quality of life. Severe Renal Impairment (RI) remains a significant challenge in newly diagnosed MM (NDMM), complicating treatment and affecting outcomes. Prior studies reported improved overall renal recovery in the era of novel therapies. However, there is a lack of evidence documenting the outcomes of patients presenting with severe RI. We present an updated analysis of the characteristics and outcomes of patients with NDMM presenting with severe RI in an ethnically diverse, low socio-economic population. Methods: A single-center retrospective review of patients with NDMM presenting to Montefiore Medical Center (Bronx, New York) was conducted from 2011-2023. Severe RI was defined as an estimated glomerular filtration rate (eGFR) of less than 30 mL/min/1.73 m². MM risk was assessed using the mSMART 3.0 tool. Results: Out of 284 patients with NDMM, 58 (20%) patients presented with severe RI. Black patients (p = 0.018) and older adults (64 years vs 60 years, p value 0.032) were more likely to present with severe RI. Severe RI at diagnosis correlated with high-risk myeloma (p = 0.002), high R-ISS stage (p < 0.001), and a lower likelihood of receiving stem cell transplants (p < 0.001). Among those with severe RI, 23/58 required dialysis of which 6/23 were taken off dialysis at last follow-up after renal recovery. Median eGFR at diagnosis, 6 months and 1 year after diagnosis was 11, 23 and 23.5 ml/min/1.73 m2, respectively. 14 out of 58 patients (39%) achieved renal recovery to eGFR > 30 one year post-diagnosis, with no significant difference in race, sex, or ethnicity. The most common first-line treatment for patients with severe RI was CyBorD (62%). The median time from diagnosis to first treatment (including plasma exchange) was 10 days. By the last follow-up, 35/58 patients (60%) had a stem cell transplant, with a median time from diagnosis to transplant of 275 days. The median overall survival (OS) for patients with severe RI at diagnosis was 49 months, while it was not reached for those without severe RI (p < 0.001). Early death (≤ 2 months after diagnosis) occurred in 2 patients, both with severe RI. Among patients with severe RI, multivariate Cox regression survival analysis showed that achieving free light chain (FLC) below 500 mg/L (HR 0.212, p < 0.001) and receiving a stem cell transplant (HR 0.209, p 0.002) improved outcome. Conclusions: Despite improvements in the life expectancy of patients with MM, severe renal failure remains a challenge, particularly among minorities. Socioeconomic factors need to be explored as a contributor to outcomes in patients with severe RI. Achieving FLC clearance and undergoing stem cell transplant may play a role in survival in patients with NDMM and severe RI.