Back to Authors

Hentz, Roland

Mayo Clinic

Mayo Clinic

Citations 13

Comparative Analysis of Familial Versus Infectious Neonatal Hemophagocytic Lymphohistiocytosis
Greenmyer, Jacob R. , Anderson, Megan L., Cameron, Charles S., Kranz, Lincoln A., Hahn, Wyatt S., Kohorst, Mira A. , Martin, Catherine, Galardy, Paul J. , Hentz, R. C., Cameron, Charles S., Thompson, Whitney S. , Ferdjallah, Asmaa , Kuhn, Alexis , Hentz, Roland

Journal of Pediatric Hematology/Oncology | March 27, 2026 | Volume: 48 | Issue: 3 | Pages: 114-124

10.1097/mph.0000000000003178 Get It

There have been no large comparisons of the clinical and laboratory features of familial neonatal hemophagocytosis (f-nHLH) and infectious neonatal hemophagocytosis (i-nHLH). The objectives of this study were the following: (1) Describe the demographic, diagnostic, and clinical features of patients with familial nHLH (F-nHLH) and infectious HLH (i-nHLH). (2) Compare key variables between f-nHLH and i-nHLH. (3) Compare the clinical outcomes of f-nHLH and i-nHLH. (4) Summarize literature on cytokine levels in patients with nHLH. Data from a previously published nHLH meta-analysis report were used to describe and compare features of infants with f-nHLH versus i-nHLH. Variables were tested with the χ 2 test or Fisher exact test, Cochran-Armitage test, independent 2-sample t test, or Wilcoxon rank-sum test as appropriate. Odds ratios were calculated for any comparison with a P -value of <0.05. Data extracted from 99 cases of f-nHLH and 54 cases of i-nHLH were included in this analysis. Infants with f-HLH met HLH criteria at the following rates: fever (84%); organomegaly (100%); pancytopenia (75%); hypofibrinogenemia (84%); hypertriglyceridemia (48%); hypofibrinogenemia or hypertriglyceridemia (82%); hemophagocytosis (81%); hyperferritinemia (99%); low or absent NK cell activity (91%); and elevated soluble CCD25 (91%). Infants with i-nHLH had higher median ferritin levels (22,537 ng/mL) than infants with f-nHLH (7587 ng/mL) ( P =0.072). Infants with f-nHLH had higher rates of symptoms in utero, preterm birth, family history of HLH, and family history of infant death. The overall survival among infants with familial nHLH was lower than infectious nHLH ( P =0.037). Management of nHLH requires rapid diagnosis and prompt treatment, as current literature suggests nHLH has high mortality rates. Distinguishing between familial and infectious causes of nHLH can aid in determining the correct treatment of choice.
Abstract PS1-10-22: Tumor-infiltrating lymphocytes in advanced ER-positive, HER2-negative breast cancer prior to treatment with palbociclib and endocrine therapy: a retrospective analysis of the PROMISE study
O'Sullivan, C. C., Moyer, A. M., Nassar, A., Zahrieh, D. M., Suman, V., Tang, X., Thompson, K. J., Hentz, R. C., Harrington, J. J., Moreno-Aspitia, Alvaro, Northfelt, D. W., Haddad, T. C., Chumsri, S., Peethambaram, P. P., Ruddy, K. J., Giridhar, K. V., Leon-Ferre, R. A., Weinshilboum, R., Wang, L., Kalari, K. R., Goetz, M. P., O’Sullivan, Ciara C. , Zahrieh, David , Hentz, Roland, Northfelt, Donald W. , Chumsri, S., Peethambaram, Prema P. , Ruddy, Kathryn J. , Leon‐Ferre, Roberto A. , Kalari, KR, Goetz, Matthew P.

Clinical Cancer Research | February 17, 2026 | Volume: 32 | Issue: 4_Supplement | Pages: PS1-10-22-PS1-10-22

10.1158/1557-3265.sabcs25-ps1-10-22 Get It

Abstract Background: Tumor-infiltrating lymphocytes (TILs) in HER2+ and triple-negative breast cancer (BC) are prognostic and associated with therapy response; however, there are few data regarding distribution and significance of TIL values in ER+ HER2-negative (HER2-) MBC patients (pts) treated with CDK4/6 inhibitors (CDK4/6i). CDK4/6 inhibition may promote antitumor immunity by production of type III interferons and tumor antigen presentation, and by inhibition of regulatory T cells (Goel, Nature 2017). Further, the addition of immune checkpoint therapy to palbociclib numerically prolonged PFS in the 2nd line (2L) setting (Mayer, JCO 2024). We aimed to investigate the prognostic role of TILs derived from fresh metastatic tumor biopsies in pts with ER+HER2- MBC prior to starting CDK4/6i and endocrine therapy (ET) in the first line (1L) and 2L setting. Methods: PROMISE (NCT0281902) is a multicenter, prospective study that enrolled women commencing the CDK4/6i palbociclib (Pb) with letrozole (1L) or fulvestrant (2L) for HR+HER2- MBC. The primary goal was to identify novel genomic variants and pathways associated with PFS. Here, we performed a secondary analysis to quantitate stromal TILs using protocol mandated pretreatment tumor biopsies and determine their association with PFS. Using the Kaplan-Meier method, we reported median PFS (mPFS) and 3-year PFS percentage (%) (95% confidence intervals [CIs]) by TILs [≥20% vs &lt;20%] separately within 1L and 2L. As sample TIL values were generally concentrated at zero (27/58 = 46.6%), coupled with wide spread of sample TIL values ≥20% [range: 20%- 80%], we applied a ≥20% threshold for PFS analysis (high vs low TIL group) as described by Luen, Salgado et al. Lancet Oncol 2017. Statistical significance was based on the Wilcoxon test of the null hypothesis that there was no difference in the PFS curves by TILs. PFS is reported at median follow-up of 21 months. Results: Pretreatment tumor biopsies from 58/68 (85.3 %) pts were evaluable (42 in 1L and 16 in 2L). Median [Q1, Q2] TIL values were higher in 1L (5% [0, 10]) vs 2L (0% [0, 15]). The most common biopsy sites were bone (44.8%), lymph node (17.2%), liver (17.2%) and breast (12%). Overall, TILs frequency (&gt;20%) by the 4 most common biopsy sites were bone (2/20, 10%), lymph node (4/7, 57%), liver (2/6, 33%), and breast (1/7, 14%). In 1L, although PFS was not significantly different (P = 0.237), mPFS (44 vs 34 months) and 3-year PFS 75.0%, [95% CI: 50.3%, 100%] vs 46.4% [95% CI: 31.0%, 69.5%]) were longer in pts with high versus low TILS, respectively. In 2L, the 3-year PFS was numerically similar comparing high and low TILs groups, (25.0%, [95% CI: 4.6%, 100%] vs 22.5% [95% CI: 6.7%, 76.1%]) with no significant difference in PFS (P = 0.761). Conclusions: In pts with ER+HER2- MBC treated with Pb and ET, PFS was numerically longer comparing high vs low TIL values in 1L but not 2L settings. Future studies evaluating TILs in larger datasets are needed to validate these findings. Genomic analysis (DNA/RNA) and its association with TIL levels is underway and will be presented at the meeting. Funding: The Center for Individualized Medicine, Mayo Clinic; Mayo Clinic Breast Specialized Program of Research Excellence (SPORE P50CA116201); Mayo Clinic Cancer Center (CA15083-40A2); TEMPUS (https://www.tempus.com/) and Conquer Cancer Foundation of ASCO (Career Development Award 2018, Dr. O’Sullivan) Citation Format: C. C. O'Sullivan, A. M. Moyer, A. Nassar, D. M. Zahrieh, V. Suman, X. Tang, K. J. Thompson, R. C. Hentz, J. J. Harrington, A. Moreno-Aspitia, D. W. Northfelt, T. C. Haddad, S. Chumsri, P. P. Peethambaram, K. J. Ruddy, K. V. Giridhar, R. A. Leon-Ferre, R. Weinshilboum, L. Wang, K. R. Kalari, M. P. Goetz. Tumor-infiltrating lymphocytes in advanced ER-positive, HER2-negative breast cancer prior to treatment with palbociclib and endocrine therapy: a retrospective analysis of the PROMISE study [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS1-10-22.
Socioeconomic status and concussion recovery in young athletes
Kreitner, Liga , Crowley, Eric M., Hentz, Roland, Soma, David , Kreitner, Liga A , Hentz, Roland C, Soma, David B, Wi, Chung‐Il

The Physician and Sportsmedicine | November 13, 2025 | Volume: 53 | Issue: 6 | Pages: 500-506

10.1080/00913847.2025.2590420 Get It

Standardizing Antimicrobial Prophylaxis in Pediatric Patients Requiring Extracorporeal Membrane Oxygenation
Mitzelfelt, Jordon C., Hentz, Roland, Ristagno, Elizabeth H. , Kanade, Rahul , Dinnes, Laura , Shah, Adi, Aganga, Devon O. , Levy, Emily R. , Levy, Emily R , Mitzelfelt, Jordon C , Shah, Adi, O’Horo, John C.

Pediatric Infectious Disease Journal | September 18, 2025 | Volume: 45 | Issue: 3 | Pages: 245-250

10.1097/inf.0000000000005008 Get It

Background: Prophylactic antimicrobials for pediatric patients requiring extracorporeal membrane oxygenation (ECMO) support are not well delineated; there are no consistent guidelines nationally or internationally. We analyzed antimicrobial use before and after implementing a narrow-spectra ECMO antimicrobial prophylaxis protocol intended to standardize prophylaxis by risk related to ECMO type and configuration. Methods: This retrospective, single-center study included children under 18 years old requiring ECMO between May 2018 and December 2021. Medical and cardiac surgical patients requiring open-chested (central) or peripheral veno-venous or veno-arterial ECMO were included. We evaluated the impact of an ECMO antimicrobial prophylaxis protocol by comparing the appropriateness of antimicrobial use as well as nosocomial infections in the pre versus post protocol. Results: Our study included 55 children with 58 individual ECMO episodes. More than 50% of the patients were open-chested during ECMO support, and the majority of ECMO support was veno-arterial. In the post protocol period, patients were 4 times as likely to have appropriate antimicrobial prescribing (Odds ratio 4.4; 95% confidence interval: 1.1–19; P = 0.036), including both prophylactic (per protocol) and therapeutic (chart documentation of an infection with appropriate therapeutic antimicrobials, including drug and duration). There was no difference in the odds of nosocomial infection occurring during ECMO pre protocol versus post protocol (pre vs. post protocol, P = 0.71 for invasive infections, P = 0.73 for all infections including potential colonization). Conclusions: After implementation of a standardized narrow-spectra ECMO antimicrobial prophylaxis protocol, we observed an increase in appropriate and standardized antimicrobial prescribing without concomitant increase in nosocomial infections.
Weight loss following lisdexamfetamine in children and adolescents with attention deficit hyperactivity disorder and overweight and obesity
Salama, Mostafa , Leopold, Kaitlin , Hentz, Roland, Kumar, Seema , Salama, Mostafa

Pediatric Obesity | May 15, 2025 | Volume: 20 | Issue: 8 | Pages: No page available

10.1111/ijpo.70024 Get It

SummaryObjectiveTo examine change in weight status following initiation of lisdexamfetamine in children with attention deficit hyperactivity disorder (ADHD) and overweight or obesity.Study DesignA retrospective chart review included children aged 2 to <18 years treated with lisdexamfetamine for ADHD. Body mass index (BMI) data for up to 2 years after initiation of lisdexamfetamine were analysed using linear mixed effects models with autoregressive‐1 correlation structure on time of follow‐up per patient.ResultsThe analysis included 330 children ≤18 years, median age 10 years (interquartile range 8.1–13) comprising 55 children with severe obesity, 88 with mild‐moderate obesity, 131 with overweight and 56 with healthy weight, 68% male and 32% female. At 2 years after initiation of lisdexamfetamine in the severe obesity group, the BMI Z‐score decreased by −0.41 (95% confidence intervals [CI] [−0.57, −0.25], p < 0.001) and BMI percent of the 95th percentile decreased by −11.2% (95% CI [−15.8 to −6.7], p < 0.001). In the mild–moderate obesity group, BMI Z‐score decreased by −0.44 (95% CI [−0.56, −0.31], p < 0.001) and BMI% of the 95th percentile decreased by −11.1% at 24 months (95% CI [−13.9 to −8.4], p < 0.001). In the mild–moderate obesity and overweight groups, younger children (ages 4–10) showed greater reduction in their BMI (p < 0.001 and p = 0.029, respectively).ConclusionReduction in BMI for age was noted for up to 2 years following initiation of lisdexamfetamine in children with ADHD and overweight and obesity. Further studies are warranted to study the weight loss effect of lisdexamfetamine in children with obesity.
Cardiometabolic Risk Markers in Children With Obesity and Variants in MC4R Pathway-related Genes
Salama, Mostafa , Hentz, Roland, Nofal, Alaa Al , Hassan, Sara, Ibrahim, Samar H. , Lteif, Aida, Creo, Ana L. , Pittock, Siobhán T. , Kumar, Seema , Vairo, Filippo , Creo, Ana , Pittock, Siobhan , Kumar, Seema , Salama, Mostafa , Al Nofal, Alaa , Ibrahim, Samar H , Vairo, Filippo Pinto e

Journal of the Endocrine Society | July 25, 2024 | Volume: 8 | Issue: 9 | Pages: No page available

10.1210/jendso/bvae137 Get It

Abstract Context Variants in melanocortin 4 receptor (MC4R) pathway-related genes have been associated with obesity. The association of these variants with cardiometabolic parameters are not fully known. Objective We compared the severity of obesity and cardiometabolic risk markers in children with MC4R pathway-related clinically reported genetic variants relative to children without these variants. Methods A retrospective chart review was performed in children with obesity who underwent multigene panel testing for monogenic obesity. Results Data on a total of 104 children were examined, with 93 (89%) identified as White. Thirty-nine (37.5%) patients had clinically reported variants in the MC4R pathway, and the remaining 65 patients did not have reported MC4R pathway-related variants. Among the MC4R-related variants, PCSK1 risk alleles were most common, reported in 15 children (14%). The maximum body mass index percent of the 95th percentile was not different between groups (P = .116). Low-density lipoprotein cholesterol (LDL-C) was not different between groups (P = .132). However, subgroup analysis demonstrated higher LDL cholesterol in children with the PCSK1 c.661A&gt;G risk allele relative to those with MC4R-related variant of uncertain significance (P = .047), negative genetic testing (P = .012), and those with non-MC4R related variants (P = .048). The blood pressure, fasting glucose, hemoglobin A1C, total cholesterol, alanine transaminase, and high-density lipoprotein cholesterol were not different between groups. Conclusion Variants in the MC4R pathway-related genes were not associated with severity of obesity and cardiometabolic risk markers except for the c.661A&gt;G PCSK1 risk allele, which was associated with higher LDL-C levels.
Primary hyperoxaluria: Long‐term outcomes of isolated kidney versus simultaneous liver/kidney transplant
Habash, Nawras W. , Jaoudeh, Rasha Abi Radi Abou , Hentz, Roland, Sas, David J. , Ibrahim, Samar H. , Hassan, Sara , Jaoudeh, Rasha A R A, Hentz, Roland C, Ibrahim, Samar H , Hassan, Sara

Journal of Pediatric Gastroenterology and Nutrition | July 15, 2024 | Volume: 79 | Issue: 4 | Pages: 826-834

10.1002/jpn3.12315 Get It

AbstractObjectivesTo compare long‐term transplant outcomes (organ rejection and retransplant) of simultaneous liver/kidney transplant (SLK) versus isolated kidney transplant (IK) for patients with primary hyperoxaluria (PH).MethodsThe Rare Kidney Stone Consortium PH registry was queried to identify patients with PH who underwent SLK or IK from 1999 to 2021. Patient characteristics and long‐term transplant outcomes were abstracted and analyzed. Statistical comparisons were performed with Kaplan–Meier plots and Cox proportional hazards models.ResultsWe identified 250 patients with PH, of whom 35 received care at Mayo Clinic and underwent SLK or IK. Patients who underwent SLK as their index transplant had lower odds of kidney rejection than did those who underwent IK (hazard ratio [HR], 0.29; 95% confidence interval [CI], 0.08–0.99; p = .048). The immunoprotective effect of concomitant liver and kidney transplant appeared to enhance outcomes for patients with PH. Additionally, the odds of retransplant were significantly lower for patients who underwent SLK as their index transplant than for those who underwent IK (HR, 0.08; 95% CI, 0.02–0.42; p = .003). Of five patients who underwent IK and had maintained graft function for at least 5 years after transplant, three (60%) had documented vitamin B6 responsiveness.ConclusionsPatients with PH who underwent SLK had a lower risk of kidney rejection and retransplant than those who underwent IK. Accurate genetic assessment for vitamin B6 responsiveness may optimize IK allocation. Novel therapeutics, such as lumasiran, have been introduced as promising agents for the management of PH.
Neonatal hemophagocytic lymphohistiocytosis: A meta‐analysis of 205 cases
Kranz, Lincoln A., Hahn, Wyatt S., Hentz, Roland, Kobrinsky, Nathan L. , Galardy, Paul J. , Greenmyer, Jacob R. , Thompson, Whitney S. , Galardy, Paul J , Greenmyer, Jacob R

Pediatric Blood & Cancer | January 31, 2024 | Volume: 71 | Issue: 4 | Pages: No page available

10.1002/pbc.30894 Get It

Abstract Background Neonatal hemophagocytic lymphohistiocytosis (nHLH), defined as HLH that presents in the first month of life, is clinically devastating. There have been few large descriptive studies of nHLH. Objectives The objective of this study was to perform a meta‐analysis of published cases of nHLH. Methods A comprehensive literature database search was performed. Cases of HLH were eligible for inclusion if clinical analysis was performed at age ≤30 days. Up to 70 variables were extracted from each case. Results A total of 544 studies were assessed for eligibility, and 205 cases of nHLH from 142 articles were included. The median age of symptom onset was day of life 3 (interquartile range [IQR]: 0–11, n = 141). Median age at diagnosis was day of life 15 (IQR: 6–27, n = 87). Causes of HLH included familial HLH (48%, n = 99/205), infection (26%, n = 53/205), unknown (17%, n = 35/205), macrophage activation syndrome/rheumatologic (2.9%, n = 4/205), primary immune deficiency (2.0%, n = 5/205), inborn errors of metabolism (2.4%, n = 5/205), and malignancy (2.0%, n = 4/205). Fever was absent in 19% ( n = 28/147) of all neonates and 39% ( n = 15/38) of preterm neonates. Bicytopenia was absent in 26% ( n = 47/183) of patients. Central nervous system (CNS) manifestations were reported in 63% of cases ( n = 64/102). Liver injury (68%, n = 91/134) and/or liver failure (24%, n = 32/134) were common. Flow cytometry was performed in 22% ( n = 45/205) of cases. Many patients (63%, n = 121/193) died within the period of reporting. Discernable values for HLH diagnostic criteria were reported between 30% and 83% of the time. Conclusions Evaluation of nHLH requires rapid testing for a wide range of differential diagnoses. HLH diagnostic criteria such as fever and bicytopenia may not occur as frequently in the neonatal population as in older pediatric populations. Neurologic and hepatic manifestations frequently occur in the neonatal population. Current reports of nHLH suggest a high mortality rate. Future publications containing data on nHLH should improve reporting quality by reporting all clinically relevant data.
First-Generation Cephalosporins for Treatment of Acute Hematogenous Osteomyelitis in Children: A Study of Efficacy and Adverse Effects
Hiskey, Lisa , Saifuddin, Hiba, Levy, Emily R. , Hentz, Roland, Rajapakse, Nipunie , Dinnes, Laura , Ristagno, Elizabeth H. , Rajapakse, Nipunie S , Dinnes, Laura M., Levy, Emily R

Open Forum Infectious Diseases | December 13, 2023 | Volume: 10 | Issue: 12 | Pages: No page available

10.1093/ofid/ofad610 Get It

Abstract Background Acute hematogenous osteomyelitis (AHO) is a relatively infrequent but significant infection in pediatric patients. As Staphylococcus aureus is the most common cause of AHO, intravenous and oral first-generation cephalosporins are common therapies. Cephalexin is a commonly prescribed oral therapy for pediatric AHO, although it requires frequent dosing that may affect adherence. Cefadroxil is a comparable oral first-generation cephalosporin with a more desirable dosing schedule. Methods We reviewed pediatric patients admitted to Mayo Clinic between March 2002 and September 2020 for management of AHO who received treatment with a first-generation cephalosporin. We reviewed timing of oral therapy transition, therapy-associated adverse effects, and recurrence of disease after completion of therapy. Results There were 59 patients included in the study. There was similar occurrence of adverse effects in patients receiving cefadroxil and cephalexin, although use of cefadroxil coincided with more gastrointestinal adverse effects and leukopenia and use of cephalexin with more rash and neutropenia. One secondary treatment failure occurred in our study, in a patient receiving cephalexin for treatment of septic arthritis. Conclusions Cefadroxil may be a reasonable alternative oral therapy for methicillin-susceptible S aureus or culture-negative AHO in pediatric patients, particularly when a less frequent dosing schedule is desired. Future study with a larger sample size is warranted.
Neonatal Hemophagocytic Lymphohistiocytosis: Scoping Review and Analysis of 205 Cases
Kranz, Lincoln A., Hahn, Wyatt S., Thompson, Whitney, Hentz, Roland, Kobrinsky, Nathan L. , Galardy, Paul J. , Greenmyer, Jacob R.

Blood | December 1, 2023 | Volume: 142 | Issue: Supplement 1 | Pages: 5350-5350

10.1182/blood-2023-182092 Get It

Background: Hemophagocytic lymphohistiocytosis (HLH) is a syndrome of pathologic immune activation and uncontrolled inflammation. Neonatal HLH (nHLH), defined as HLH that presents in the first month of life, is clinically devastating. nHLH is estimated to comprise 10% of familial HLH (fHLH) diagnoses. There have been few, large descriptive studies of nHLH. Objectives: The primary objective of this study was to perform a scoping review and descriptive analysis of published cases of nHLH. The secondary objective of this study was to assess the reporting quality of published nHLH cases. Methods: A comprehensive literature database search was performed. Cases of HLH were eligible for inclusion if clinical analysis was performed at age &lt; 30 days. As many as 70 variables were extracted from each case. Frequencies and percentages of variables reported per case in the articles included were provided. Qualitative variables were summarized by frequency and percentage. Quantitative variables which were not approximately normally distributed were summarized with median and interquartile range (IQR). Results: 544 studies were assessed for eligibility. Studies were excluded if they did not discuss nHLH (n=280), aggregated nHLH patient data with all ages (n=83), provided insufficient detail and/or data describing nHLH (n=28), and for other reasons (n=8).205 cases of nHLH from 142 articles were included. Cases were published from 31 countries from 1985-2023. Primary presenting features included fever (38.1%, n=67/176), organomegaly (11.9%, n=21/176) respiratory distress (11.4%, n=20/176), jaundice (4.5%, n=8/176), and signs of bleeding (3.4%, n-6/176). Symptoms began in utero in 20 patients (n=20/161). The median age of symptom onset was day of life (DOL) 3 (IQR: 0-14) (n=141). Median age at diagnosis was DOL 15 (IQR: 6-27) (n=87). The median time from initial evaluation to initiation of HLH therapy was 8 days (IQR: 3-14) (n=53). The frequency of HLH criteria and criteria median values are summarized in Table 1. The median number of diagnostic criteria met by patients were 5/8 (IQR: 4, 6). CNS manifestations were reported in 62.7% of cases (n=64/102). Skin manifestations were reported in 75.4% of cases (n=52/69). Liver injury (67.9%, n=91/134) and/or liver failure (23.9%, n=32/134) were common. Infections were reported in 46.7% of patients (n=70/150). Causes of nHLH included familial/inherited disease (46.8%, n=96/205), infection (26%, n=53), macrophage activation syndrome (2.9%, n=6), primary immunodeficiency (2.9%, n=6), inborn error of metabolism (2.4%, n=5), and malignancy (2%, n=4). Diagnosis was made using clinical and laboratory features (82.4%, n=169/205), gene panel (16.1%, n=33/205), sanger sequencing (1.0%, n=2/205), and ultra-rapid whole genome sequencing (0.5%, n=1/205). Genetic causes of fHLH included mutations in PRF1, STX11, STXBP2, UNC13D, NOCAR-H, and XIAP. The majority of patients (62.7%, n=121/193) died within the period of reporting. The estimated median survival time from nHLH onset of symptoms was 83 days. Only 4.4% (n=9/205) of studies reported complete data to calculate an H-score. Studies reported discernable values for HLH diagnostic variables at the following frequencies: temperature (71.7%), organomegaly (82.9%), hemoglobin (69.3%), thrombocytopenia (82.4%), neutrophils (55.1%), fibrinogen (64.4%), triglycerides (5.5%), hemophagocytosis (73.2%), ferritin (71.2%), low/absent NK cell activity (33.2%), and sIL2R (29.3%). Other clinically relevant variables such as the presence or absence of skin manifestations (33.7%), and CNS manifestations (49.8%) frequently went unreported. There were many cases that made a categorical description of a lab value (e.g., thrombocytopenia) without providing an absolute value (e.g., platelets level). Conclusions: This is the largest aggregated study of nHLH presentations, diagnostic criteria, clinical trajectory, and etiologic diagnoses. Neurologic, dermatologic, and hepatic manifestations occur in the neonatal population. Current reports of nHLH suggest a grim prognosis. Future publications containing data on nHLH should report all clinically relevant variables. Studies looking at multiple patients in aggregate should provide supplemental information with detailed nHLH cases.