Immune reconstitution and survival, following hematopoietic stem cell transplantation in Omani patients with inborn errors of immunity.

BACKGROUND: Hematopoietic stem cell transplantation (HSCT) is a curative treatment for certain inborn errors of immunity. METHODS: A 17-year retrospective cohort study was conducted on 40 immunodeficient patients who underwent HSCT. RESULTS: The median age at transplant was 11.0 months (4.6-61.0). Donors were primarily matched sibling donors (60%). 90% and 85% of patients received conditioning and graft-versus-host disease (GVHD) prophylaxis, respectively. The mean donor chimerism at the last follow-up was 88.6% ± 17.9% (40-100). Median serum immunoglobulin (Ig) G level, CD4+ T-cell count, and CD19+ B-cell count were 11.7 g/L (9.2-13.6), 0.9 × 109/L 0.6-1.2), and 0.5 × 109/L (0.2-0.7), respectively. 29 patients (72.5%) received intravenous immunoglobulins (IVIG) therapy, with a median duration of 10.0 months (4.0-14.0). The median post-transplant follow-up was 6.5 years (IQR:1.4-11.5). The 10-year overall probability of survival is 84.3%. CONCLUSION: Monitoring IRC is important in ensuring adequate disease-free survival.

Efficiency of day 4 compared to day 6 stem cell mobilization in allogeneic stem cell donors.

BACKGROUND: Granulocyte colony stimulating factor (G-CSF) given for 4-6 days is commonly used for mobilization of allogeneic stem cell donors. The primary objective of this study is to compare the yield of stem cell mobilization, assessed using a surrogate endpoint of CD34+ cell count, between Day 4 and Day 6. STUDY DESIGN AND METHODS: In this retrospective study we included all allogeneic stem cell donors mobilized with G-CSF for 6 days from January 2003 until October 2015 in the bone marrow transplantation unit at a tertiary academic center. Of 106 donor records reviewed, 84 were with available data and selected for the study. RESULTS: We included 84 donors with median age and weight of 19 years and 60 kg respectively. The median Day 4 WBC and CD34+ cell count were 37.4 × 109/L and 54 × 106/L respectively; while the median Day 6 WBC and CD34+ cell count were 44.4 × 109/L and 86 × 106/L respectively with a statistically significant difference from Day 4 (P < 0.001). In the multivariable model, there were no significant impact of donor's age (P = 0.215), weight (P = 0.108), height (P = 0.428) and mean corpuscular volume (P = 0.263) on the difference in CD34+ cell yield. However, the donor's blood group AB predicated a significantly higher difference (P = 0.036). CONCLUSION: Six days of G-CSF mobilization achieves higher CD34+ cell count than 4 days in allogeneic stem cell donors especially in donors with blood group AB, albeit both approaches give count higher than the successful collection threshold.

The role of preoperative transfusion in sickle cell disease, a systematic review and meta-analysis.

This systematic review and meta-analysis aimed to provide guidance on preoperative blood transfusion strategies for patients with sickle cell disease (SCD). We included all randomized controlled and observational studies exploring the clinical outcomes of preoperative blood transfusion among patients with SCD compared to the conservative transfusion strategy until 14/09/2022. Sixteen studies involving 3486 participants were analysed. The findings revealed a significantly higher bleeding rate in patients who received preoperative transfusion than those who followed a conservative strategy (RR = 4.32, 95% CI 1.75-10.68, P = 0.002, I2 = 0%). However, the two strategies had no significant differences in other clinical outcomes, such as acute chest syndrome, painful crisis, fever, neurological complications, thrombosis, ICU admission, and mortality. It is important to note that all the included studies had a moderate risk of bias. Preoperative transfusion in SCD was associated with a higher bleeding risk but a similar risk in other outcomes compared to conservative strategies. Notably, the increased bleeding risk observed seldom had clinical significance. We recommend individualizing management strategies, considering the overall positive impact of transfusions in reducing complications. Further high-quality studies are needed to refine recommendations.

Current Status and Management of Chronic Myeloid Leukemia in the Gulf Region: Survey Results and Expert Opinion.

Studies on chronic myeloid leukemia (CML) in the Gulf region are scarce, consisting of a survey and expert meeting that included 15 experts in 2023 which discussed CML diagnosis, testing, treatment objectives, toxicities, and discontinuation in the Gulf region. Most patients were reported to be in first-line therapy, and the most common treatments were imatinib/imatinib generic in first-line and dasatinib in second- and third-lines. Mutation analysis was not reported to be routinely performed at the time of diagnosis but rather in case of progression to accelerated/blast phase or any sign of loss of response. While all participants were aware that BCR-ABL should be monitored every three months during the first year of treatment, 10% reported monitoring BCR-ABL every six months in practice due to test cost and lab capability. The most important first-line therapy objective was "achievement of major molecular response" (MMR) in younger patients and "overall survival" in older ones. The most important treatment objectives were "MMR" and "early molecular response followed by prolongation of overall survival" in the short term and "treatment-free remission" in the long term. The current practices in CML in the Gulf region appear to be similar to global figures.

Chronic myeloid leukemia diagnosed in pregnancy: management and outcome of 87 patients reported to the European LeukemiaNet international registry.

The management of chronic myeloid leukemia (CML) diagnosed during pregnancy is a rare and challenging situation. We report the treatment and outcome of 87 cases diagnosed in chronic phase from 2001-2022 derived from the largest international observational registry, supported by the European LeukemiaNet (ELN), of 400 pregnancies in 299 CML women. Normal childbirth occurred in 76% without an increased rate of birth abnormalities or life-threatening events, including in patients untreated or treated with interferon-α and/or imatinib in 2nd-3rd trimester. The low birth weight rate of 12% was comparable to that seen in the normal population. Elective and spontaneous abortions occurred in 21% and 3%, respectively. The complete hematologic response rate before labor was 95% with imatinib and 47% with interferon only. No disease progression during pregnancy was observed, 28% of the patients switched their therapy at varying times after delivery. Treatment options balance the efficacy and safety for mother and infant: interferon-α can commence in the 1st trimester and continued throughout in cases of good disease control and tolerability. Because of limited placental crossing, selected tyrosine kinase inhibitors (imatinib and nilotinib) seem to be safe and effective options in 2nd and 3rd trimester while hydroxycarbamide offers few benefits.

Outcome of pregnancy in sickle cell anemia patients with COVID-19 infection.

Sickle cell anemia (SCA) is a multisystem disease, associated with increased risk for infection and thromboembolic disease, and pregnancy is a stressor for patients with SCA. In general, coronavirus disease 2019 (COVID-19) infection in SCA is associated with a favorable outcome. Literature of pregnancy in SCA with COVID is scarce. We report a case series study of pregnant women with SCA, who are confirmed positive for COVID-19 from May 2020 to March 2021. These patients showed generally mild-to-moderate disease and presented predominantly with fever and painful crisis. They showed a significant drop in Hb from baseline, and they received low-molecular-weight heparin prophylaxis (LMWH) and blood transfusion. The outcome of pregnancy is satisfactory, although the mean birth weight was significantly lower than that reported from the same SCA population.

Transcranial Doppler ultrasonography in sickle cell disease: a study in Omani patients.

Changes on Transcranial Doppler (TCD) ultrasonography have been proposed as significant predictors of cerebrovascular complications in sickle cell disease (SCD). However, consensus with regards to the TCD criteria to recognize abnormalities in cerebral vasculature is lacking. We studied the TCD characteristics of cerebral arteries among Omani patients with SCD and correlated them with cerebrovascular events. TCD was performed through the temporal and suboccipital windows using a 2 MHz probe (DWL). Thirty-three of 59 patients (56%) with SCD had neurological symptoms including stroke--12 (20%) and epilepsy--7. Fifteen patients (25%) had significant TCD abnormalities including: markedly increased velocities--11 (3 with stroke); turbulent flow--2; and reversal of flow--2. No patient had a time averaged maximum mean velocity of >200 cm/s in anterior circulation. On applying a modified definition of "abnormal TCD" to anterior and posterior circulation studies, increased TCD velocities in posterior circulation correlated with history of stroke (P < 0.05). TCD velocities in the 18 adult patients ( older than 15 y) were significantly lower than in children. Logistic regression analysis revealed abnormal TCD in the left posterior cerebral artery to be an independent predictor of stroke in this cohort (P = 0.035).

Differential Production of Midkine and Pleiotrophin by Innate APCs upon Stimulation through Nucleic Acid-Sensing TLRs.

Midkine (MK) and pleiotrophin (PTN) belong to the same family of cytokines. They have similar sequences and functions. Both have important roles in cellular proliferation, tumors, and diseases. They regulate and are expressed by some immune cells. We have recently demonstrated MK production by some human innate antigen-presenting cells (iAPCs), i.e., monocyte-derived dendritic cells (MDDCs) and macrophages stimulated through Toll-like receptor (TLR)-4, and plasmacytoid dendritic cells (pDCs) stimulated through TLR 7. While PTN production was only documented in tissue macrophages. TLRs 3, 7, 8, and 9 are nucleic acid sensing (NAS) TLRs that detect nucleic acids from cell damage and infection and induce iAPC responses. We investigated whether NAS TLRs can induce MK and PTN production by human iAPCs, namely monocytes, macrophages, MDDCs, myeloid dendritic cells (mDCs), and pDCs. Our results demonstrated for the first time that PTN is produced by all iAPCs upon TLR triggering (p < 0.01). IAPCs produced more PTN than MK (p < 0.01). NAS TLRs and iAPCs had differential abilities to induce the production of MK, which was induced in monocytes and pDCs by all NAS TLRs (p < 0.05) and in MDDCs by TLRs 7/8 (p < 0.05). TLR4 induced a stronger MK production than NAS TLRs (p ≤ 0.05). Monocytes produced higher levels of PTN after differentiation to macrophages and MDDCs (p < 0.05). The production of MK and PTN differs among iAPCs, with a higher production of PTN and a selective induction of MK production by NAS TLR. This highlights the potentially important role of iAPCs in angiogenesis, tumors, infections, and autoimmunity through the differential production of MK and PTN upon TLR triggering.

Thrombopoietin-receptor agonists for adult patients with immune thrombocytopenia: a narrative review and an approach for managing patients fasting intermittently.

Introduction: Thrombopoietin-receptor agonist (TPO-RAs) currently represent the state of art for treating immune thrombocytopenia. Their different molecular structures contribute to the difference in their pharmacodynamics and pharmacokinetics. This narrative review aims to provide an overview of the current TPO-RAs approved for primary immune thrombocytopenia (romiplostim, eltrombopag, avatrombopag) and the effect of intermittent fasting in adult patients receiving TPO-RAs. Areas covered: Literature was searched with no limits on date or language, using various combinations of keywords. Data on the pharmacokinetics, pharmacodynamics, efficacy, and safety of TPO-RAs and the effect of intermittent fasting were summarized. Expert opinion: Switching between TPO-RAs is a useful strategy to tackle some associated limitations. Romiplostim and avatrombopag have an advantage over eltrombopag as they do not require any dietary restrictions. In cases where romiplostim and avatrombopag are unavailable, patients should be educated on the appropriate administration, possible interactions, and dietary restrictions before initiating eltrombopag.

Coexistence of sickle cell disease and severe congenital neutropenia: first impressions can be deceiving.

We report an Omani family in whom the propositus had a rare coexistence of sickle cell disease and severe congenital neutropenia associated with a mutation in ELANE. In contrast to his siblings with sickle cell disease, the severity of HbSS-associated complications such as painful crises and acute chest syndrome was significantly reduced. His course of the disease had markedly worsened after initiating G-CSF therapy. These clinical observations suggest that neutropenia may ameliorate inflammatory responses and thus display a modulating factor with respect to the clinical course of sickle cell disease.

Coexistence of sickle cell disease and systemic lupus erythematosus is associated with quantitative and qualitative impairments in circulating regulatory B cells.

The incidence of connective tissue diseases such as systemic lupus erythematous (SLE), in adult patients with sickle cell disease (SCD), appears to be increasing. The exact causes underlying this increased risk are still unknown, but a link with B regulatory (Breg) cells is possible as these cells suppress inflammatory responses, and maintain tolerance. Quantitative and qualitative analyses of circulating Breg cells were performed in a cohort of SCD patients with SLE, and their levels were correlated with key soluble mediators promoting autoreactive B cells. We demonstrated that levels of Breg cells were significantly decreased in SCD patients with SLE compared to patients with SCD only or healthy controls. Functional analysis of Breg cells from SCD patients with SLE revealed impairments in IL-10 production that correlated with lower levels of STAT3 phosphorylation, without abnormal expression of IL-10 receptor on Breg cells. On the other hand, BAFF levels were substantially elevated in SCD patients with SLE, but not significantly associated with Breg cell levels. Collectively, these results indicated numerical and functional deficits of Breg cells in SCD patients with SLE and their capacity to maintain tolerance and control inflammation is imbalanced, which leads to the development of autoimmune responses.

Human macrophages and monocyte-derived dendritic cells stimulate the proliferation of endothelial cells through midkine production.

The cytokine midkine (MK) is a growth factor that is involved in different physiological processes including tissue repair, inflammation, the development of different types of cancer and the proliferation of endothelial cells. The production of MK by primary human macrophages and monocyte-derived dendritic cells (MDDCs) was never described. We investigated whether MK is produced by primary human monocytes, macrophages and MDDCs and the capacity of macrophages and MDDCs to modulate the proliferation of endothelial cells through MK production. The TLR stimulation of human monocytes, macrophages and MDDCs induced an average of ≈200-fold increase in MK mRNA and the production of an average of 78.2, 62, 179 pg/ml MK by monocytes, macrophages and MDDCs respectively (p < 0.05). MK production was supported by its detection in CD11c+ cells, CLEC4C+ cells and CD68+ cells in biopsies of human tonsils showing reactive lymphoid follicular hyperplasia. JSH-23, which selectively inhibits NF-κB activity, decreased the TLR-induced production of MK in PMBCs, macrophages and MDDCs compared to the control (p < 0.05). The inhibition of MK production by macrophages and MDDCs using anti-MK siRNA decreased the capacity of their supernatants to stimulate the proliferation of endothelial cells (p = 0.01 and 0.04 respectively). This is the first study demonstrating that the cytokine MK is produced by primary human macrophages and MDDCs upon TLR triggering, and that these cells can stimulate endothelial cell proliferation through MK production. Our results also suggest that NF-κB plays a potential role in the production of MK in macrophages and MDDCs upon TLR stimulation. The production of MK by macrophages and MDDCs and the fact that these cells can enhance the proliferation of endothelial cells by producing MK are novel immunological phenomena that have potentially important therapeutic implications.

Transplant Associated Graft versus Host Disease.

Graft versus host disease (GVHD) occurs quite often after hematopoietic cell transplantation. However, it is a rare complication after solid organ transplantation and consists of a reaction of donor-derived immune cells directed against host tissues, which is mostly seen in liver, small intestine, and pancreas transplantation. We are presenting a 54-year-old man with a long-standing history of hypertension, hypertensive nephrosclerosis, and stage V terminal chronic kidney disease, who was on a regular hemodialysis thrice weekly. He had a living kidney transplantation done abroad. On returning, he had a normal kidney function with no obvious complications. Three years later, he presented with jaundice, anorexia, diarrhea, and abdominal pain. Laboratory evaluation showed marked elevated liver enzymes, and severe pancytopenia with evidence of hepatosplenomegaly. Liver biopsy was compatible with graft-versus-host-disease and toxic hepatitis. The patient was not cooperative with the management and he traveled abroad for the 2nd opinion. Based on the clinical presentations, laboratory, radiological, and pathological findings, transplant-associated GVHD (ta-GVHD) was confirmed. Unfortunately, this patient was complicated by severe sepsis, and confounded by a lack of cooperation with the management plan, which resulted in his demise. In the presence of a highly immunocompromised state, patients presenting with transaminitis/hyperbilirubinemia, and when drug-induced liver injury is excluded, the diagnosis of ta-GVHD needs to be highly considered.

The Challenges in Diagnosis and Management of Acquired Thrombotic Thrombocytopenic Purpura: Consensus Report from Three Gulf Countries.

Acquired thrombotic thrombocytopenic purpura (aTTP) is a rare hematological emergency characterized by microangiopathic hemolytic anemia, thrombocytopenia, fever, and multiorgan failure due to autoimmune-mediated deficiency in ADAMTS-13 activity. Currently, plasma exchange, with or without steroids, is the frontline option for the management of aTTP. The treatment should be started promptly once the disorder is clinically suspected. Besides, immunomodulators were studied in patients with aTTP to achieve stable remission and reduce the risk of relapse in patients with suboptimal response to plasma exchange; however, clinical trials showed equivocal results. Published data on early diagnosis, referral, and treatment patterns of aTTP patients in the member nations of the Arabian Gulf Cooperation Council (GCC) are still lacking. Therefore, the present consensus report aimed to present an overview of aTTP situation in GCC by bringing together a panel of experts from three GCC nations, to share their views on current trends and practices regarding aTTP. The experts discussed challenges including the lack of reliable data regarding the incidence of aTTP in GCC and delayed results of ADAMTS-13 activity testing. Limited patient access to tertiary centers and low level of awareness about the aTTP clinical spectrum among general practitioners are other challenges. The experts agreed that there is a need for national and regional consensus regarding the diagnosis and treatment of aTTP in the Gulf region.

Clinicopathological Profile of Paroxysmal Nocturnal Hemoglobinuria among Omani Patients: A Case Series.

We aimed to estimate the nature and prevalence of paroxysmal nocturnal hemoglobinuria (PNH) among Omani patients. We performed a retrospective review of all patients who were tested for PNH by flow cytometry at the Sultan Qaboos University Hospital, Muscat, between 2012 and 2019. Manifestations, treatment modalities, and outcomes were assessed. A total of 10 patients were diagnosed or were on follow-up for PNH (median age 22.5 years). Clinical manifestations included fatigue (80%) and anemia (70%). Six patients had classical PNH with hemolysis, three had PNH in the context of aplastic anemia, and one patient had subclinical PNH. The median total clone size (type II + III) for neutrophils was 95.5 (range: 1.5-97) (FLAER/CD24) and for monocytes was 91.6 (range = 0.04-99) (FLAER/CD14). Four patients had clone sizes > 50% at the time of diagnosis. The median follow-up period of the patients was 62 months (range = 8-204 months). One patient suffered thrombosis. Three patients were on immunosuppressant agents, five were initiated on eculizumab, and four had a bone marrow transplant. No deaths were reported in the cohort. The estimated average incidence of PNH among Omani patients was 1.5 per 5 000 000. PNH is rare in the Omani population. The predominant presentation is hemolytic anemia.

Regulatory B Cells Are Functionally Impaired in Patients Having Hemophilia A With Inhibitors.

Development of inhibitors remains a major clinical complication in patients with hemophilia A receiving replacement therapy with factor VIII (FVIII). Understanding the immune mechanisms involved in the development of inhibitors can provide valuable information about pathways to human tolerance. Recent evidence indicates that B regulatory (Breg) cells play a pivotal role in controlling the production of antibodies (Abs) while promoting follicular T helper (Tfh) cells and monocytes, expressing the low-density lipoprotein receptor-related protein (LRP/CD91), which is involved in FVIII intake from the circulation. We studied circulating levels of Breg cells along with Tfh cells and the expression of LRP/CD91 on monocytes in patients with hemophilia A using 8-color flow cytometry and cell culture. Compared to healthy controls, patients with hemophilia A with inhibitors showed a severe reduction in levels of Breg cells and produced less interleukin-10 when activated via the CD40 signaling pathway. In addition, patients with hemophilia A with inhibitors exhibited an overexpression of LPR/CD91 on monocytes and normal levels of Tfh cells. Levels of Breg cells were not significantly related to LPR/CD91 although negative associations were evidenced. Collectively, these results provide new insights into the role of Breg cells and LPR/CD91 in the development of inhibitors in patients with hemophilia A.

Can Gestational Anemia be Alleviated with Increased Awareness of its Causes and Management Strategies? Implications for Health Care Services.

OBJECTIVES: We conducted this study to assess the risk factors of gestational anemia and evaluate the effectiveness of a culturally-tailored nutrition educational intervention on hemoglobin (Hb) status among pregnant Omani women. Newborn birthweight was used as a birth outcome. METHODS: The study was conducted in two phases. The first phase investigated the risk factors associated with gestational anemia in 206 Omani women who were 3 20 years old and had at least completed 12 weeks of gestation. A suitable sample was recruited at a tertiary teaching hospital in Muscat, Oman. Hb status was recorded, and backward linear regression was used to analyze the demographic and obstetric variables associated with Hb levels. In the second phase, a specially designed culturally-tailored nutrition educational intervention was delivered to women in the study group by trained research assistants whereas women in the control group received routine care only. The Hb levels of the pregnant women and birth weight of newborns after the intervention were evaluated in the second phase of the study. RESULTS: The prevalence of gestational anemia among 206 pregnant Omani women was 41.7%. A significant negative relationship was found between Hb and parity whereas a positive relationship was found between Hb and gestational age. The Hb level increased as the gestational age advanced (ß = 0.31, p < 0.050) and decreased as the parity increased (ß = -0.22, p < 0.050). The pre-post mean difference of Hb levels in the study group was 11.0 g/dL and in the control group was 10.7 g/dL. The difference between the pre- and post-test Hb levels for the study group was significant (t = 3.58, p = 0.001), indicating that the culturally-tailored nutrition education intervention was effective in improving the Hb level in pregnant Omani women. No significant difference was found between the study and control group with respect to birth outcomes. CONCLUSION: The prevalence of gestational anemia is high in pregnant Omani women. The use of a specially designed culturally-tailored nutrition education intervention for pregnant women supplemented with follow-up reminders can reduce the occurrence of gestational anemia. Such programs are ultimately necessary in light of the high prevalence of gestational anemia in developing countries.

Cytogenetic, morphological, and immunophenotypic patterns in Omani patients with de novo acute myeloid leukemia.

Chromosome aberrations observed at diagnosis are considered to be the most valuable prognostic factors in acute myeloid leukemia (AML). Some specific aberrations vary in frequency among different geographical areas and ethnic groups. There are only limited studies on the role of such variability in AML patients. Here, we report the results of a cytogenetic study on 63 ethnic Omani patients with de novo AML: 18 children (