Johnson, Ayodeji

Abstract Background: Sickle cell disease (SCD) is marked by wide variability in clinical phenotypes and severity due to environmental, clinical, and genetic factors. Variants in iron-regulatory genes are well described modifiers of clinical presentation in different diseases, but their role in modulating SCD phenotype has been sparsely studied in African populations. In this cross-sectional study, we investigated the role of single nucleotide polymorphisms (SNPs) in iron-regulatory genes in SCD severity and lifetime transfusion(Tx) requirement. Methods: The study was approved by the institutional review board of Lagos University Teaching Hospital, Lagos, Nigeria. Clinical data were abstracted from medical records and patient interviews using a structured questionnaire. Participants were recruited in steady state and were stratified according to the severity score previously described by Shah et al. (Clinicoecon Outcomes Res. 2020;12:625). Biochemical analyses included serum transferrin and serum iron; transferrin saturation (TS) was calculated. Genotyping was performed using the Axiom Precision Medicine Research Array (PMRA; Thermo Fisher Scientific). Seventy-one single nucleotide polymorphisms (SNPs) in genes implicated in iron metabolism were analyzed, including SLC40A1 (ferroportin), HFE (homeostatic iron regulator), HJV (hemojuvelin), HAMP (hepcidin), and TFR2 (transferrin receptor 2). SNPs whose variants were not represented in this cohort, including HFE C282Y and H63D, were excluded. Ensembl and NCBI databases were used to describe the wild-type (WT)/variant alleles and gene consequences. Univariate and multivariate logistic regression were used to analyze binary outcomes, and age-adjusted linear regression for Tx burden. Odds ratios (OR) and regression coefficients (β) were estimated using the WT as the reference. Multiple-testing correction was performed as necessary. Statistical analyses were conducted in R version 4.4.1, with p<0.05 considered significant. Results: We included 60 genotyped, confirmed HbSS patients; median age was 22 years (range: 18–43), 22 (37.3%) were female, 42 (70.0%) were classified as mild severity (Class I), 5 (8.0%) as Class II, and 13 (22.0%) as severe (Class III). Twenty-seven (45.0%) had never received a blood Tx, while 33 (55.0%) had received Tx, median of 2units (range: 1-10). On univariate analysis (UVA), five SNPs (rs10218795, rs10188230, rs114250626, rs4287798, and rs634349) were significantly associated with severe phenotype; three of these remained significant on multivariable analysis (MVA). Two were associated with higher odds of severe phenotype: rs10177654 (OR = 28.9, 95% CI: 3.0–100.0, p = 0.03) and rs10218795 (OR = 15.0, 95% CI: 2.4–327.0, p<0.01), while rs10188230 was associated with lower odds (OR = 0.03, 95% CI: 0.008–0.28, p<0.01). Results remained consistent after adjusting for age. For lifetime transfusion burden, both UVA and MVA identified two significant SNPs: rs4667289, associated with higher transfusion burden (β = 2.6, 95% CI: 0.04–5.2, p = 0.047) and rs11568344, associated with lower transfusion burden (β = –1.8, 95% CI: –3.5 to –0.36, p = 0.02). Genotype distributions for the five significant SNPs were as follows: rs10177654 (SLC40A1, transcription factor binding site), TT(WT) 12 (20.3%), TC 30 (50.8%), CC 17 (28.8%); rs10188230 (SLC40A1, intron variant), TT (WT) 32 (54.2%), TC 22 (37.3%), CC 5 (8.5%); rs10218795 (HJV, intron variant), CC (WT) 22 (37.3%), TC 29 (49.2%), TT 8 (13.6%); rs4667289 (SLC40A1 proximal intergenic), GG (WT) 46 (78.0%), AG 10 (16.9%), AA 3 (5.1%); rs11568344 (SLC40A1 splice region variant), GG (WT) 47 (79.7%), AG 9 (15.3%), AA 3 (5.1%). Compared with the homozygous WT, patients with rs10188230 had a lower median TS (21.65% vs. 43.3%, p = 0.04), while those with rs4667289 had a higher median TS (83% vs. 31%, p<0.01). When adjusted for age and lifetime Tx, rs4667289 remained significant (β = 47.8, 95% CI 3.6-82.8, p = 0.03). No other SNPs showed association with TS. Conclusion: We present novel genetic data on iron-regulatory variants in African patients with sickle cell disease, identifying SNPs in SLC40A1 and HJV associated with disease severity. Most of these are yet to be fully described in the literature, and their intronic locations suggest possible regulatory roles. We hope to further validate these findings in larger cohorts and through functional studies to clarify their impact on iron metabolism and clinical significance.

Abstract Background Primary central nervous system lymphoma (PCNSL) is a rare but aggressive non-Hodgkin lymphoma with limited prospective data to guide optimal therapy. This study evaluates real-world treatment patterns and survival outcomes using a large national cohort. Methods We analyzed data from the National Cancer Database (NCDB) for patients diagnosed with PCNSL between 2004 and 2020. Baseline demographics and treatment characteristics were analyzed using descriptive statistics. Survival outcomes were estimated using the Kaplan-Meier method and compared using log-rank tests. Multivariable Cox proportional hazards models were constructed to identify independent predictors of overall survival (OS). Results A total of 14,450 patients with PCNSL were included; 14,439 had first-line treatment data available, and 13,390 had survival data. Median age at diagnosis was 67 years (range 18-90), 49.2% were female, and 6.6% were African American. Chemotherapy alone was the modality of treatment for 81.6% (n=11,787), 12.2% (n=1,769) received chemoradiation, 3.8% (n=545) received chemotherapy and underwent autologous stem cell transplant (ASCT) but no radiation, and 2.4% (n=348) received radiation only. The median follow-up time was 73.5 months (95% CI 71.4-75.6), and the median OS for the group was 17.4 months (95% CI 16.2-18.6). Survival differed significantly by age group (median OS: <65 yrs, 46.1 months [95% CI 41.7 -50.6]; 65-79 yrs, 12.5 months [95% CI 11.2-13.7]; ≥80 yrs, 3.2 months [95% CI 2.9-3.5]; p<0.001), by year of diagnosis (median OS: 2004-2009, 11.0 months [95% CI 9.9-12.1]; 2010-2015, 20.0 months [95% CI 17.4-22.6], 2016-2020, 29.7 months [95% CI 26.0-33.4]; p<0.001), and by frontline treatment strategy (p<0.001). Patients treated with chemotherapy followed by ASCT had the longest median OS (not reached), while those receiving radiation alone had the poorest outcomes with a median OS of 3.9 months (95% CI 3.2-4.7); chemoradiation patients had a median OS of 31.8 months (95% CI 27.5-36.1), and chemotherapy only patients had a median OS of 13.9 months (95% CI 12.7-15.1)(p<0.001). African American patients had an inferior outcome with a median OS of 10.2 months [95% CI 7.2-13.1], compared to “other” races with a median OS of 36.9 months [95% CI 27.6-46.1] (p<0.001), although this is more similar to the median outcome for white patients (17.0 months [95% CI 15.8-18.3]). Treatment at an academic center (25.7 vs 11.0 months) and a high case-volume center (defined as >median number of cases per facility) (18.6 vs 10.5 months), and lower Charlson-Deyo comorbidity scores (CDS) (defined as CDS 0-1) (21.7 vs 6.8 months) were also associated with superior OS (p<0.001). In multivariable analysis, increasing age ( 65-79 y.o HR 1.60 [1.52-1.1.68], ≥80 y.o HR 2.95 [2.75-3.17]), CDS≥2 (HR 1.36 [1.28-1.44]), and African American race (HR 1.12 [1.02-1.24]) were adverse predictors of OS (all p<0.001), while treatment strategy (ASCT [HR 0.17], chemoradiation [HR 0.53], chemotherapy only [HR 0.68] compared to radiation alone), more recent year of diagnosis (2010-2015 [HR 0.81], 2016-2020 [0.70]), and treatment at an academic center [HR 0.81] remained predictors of superior OS (all p<0.001). Conclusion In this large national cohort of patients with PCNSL, treatment with chemotherapy followed by ASCT was associated with the most favorable survival outcomes. Patients treated with chemoradiation or multi-agent chemotherapy also demonstrated improved survival compared to those receiving radiation monotherapy or single-agent chemotherapy alone, respectively. Age, comorbidities, race, and treatment at academic centers were also significant independent predictors of OS. These findings highlight substantial disparities in outcomes and underscore the importance of optimizing treatment strategies, improving access to high-intensity therapies, and supporting timely referral to academic or high case-volume centers, particularly for younger and medically fit patients.