Browsing by Author "Al Hammadi, Suleiman"

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BCG Vaccine–associated Complications in a Large Cohort of Children With Combined Immunodeficiencies Affecting Cellular and Humoral Immunity
(2022) Al Hammadi, Suleiman
Aims: To present the details of Bacillus Calmette-Guérin (BCG)-vaccine associated complications (VACs) in combined immunodeficiencies (CID) patients. Methods: Five centers participated in this retrospective study and completed a data form, which included general patients’ information, clinical and laboratory data. Results: Among 236 CID patients, 127 were BCG vaccinated. 41.9% of patients with family history of CID and 17.1% who were diagnosed by screening were BCG vaccinated. Twenty-three patients (18.1%) developed BCG-VACs. The median age of VACs was 6 months and the median time from vaccination to complications was 6 months. The highest rate of BCGVACs was recorded in patients receiving the Russian BCG strain compared to the Tokyo and Danish strains. Univariate analysis of T-lymphocyte subsets showed increased odds of BCG complications in patients with CD3+, CD4+, and CD8+ counts of ≤250 cells/µL. Only CD8 + count ≤250 cells/ µL had increased such odds on multivariate analysis. VACs were disseminated in 13 and localized in 10 patients. Localized complication occurred earlier after vaccination (median: 4 months) compared with disseminated ones (median: 7 months). There were no significant associations between sex, administered vaccine strain, serum immunoglobulins levels, lymphocyte subsets counts, and the chance of having either localized or disseminated BCG-related complications. Conclusions: Although contraindicated, many patients with CID continue to be vaccinated with BCG. Low CD8 + count is a risk factor for BCG– related complications and localized complications occurred earlier than disseminated ones. Considerations should be undertaken by health care authorities especially in countries with high incidence of CID to implement newborn screening, delay the time of BCG vaccine administration beyond 6 months of age and to use the relatively safer strains like the Danish and Tokyo ones.
Combined Treatment with KV Channel Inhibitor 4-Aminopyridine and either γ-Cystathionine Lyase Inhibitor β-Cyanoalanine or Epinephrine Restores Blood Pressure, and Improves Survival in the Wistar Rat Model of Anaphylactic Shock
(2022) Al Hammadi, Suleiman
Abstract: The mechanism of anaphylactic shock (AS) remains incompletely understood. The potassium channel blocker 4-aminopyridine (4-AP), the inhibitors of cystathionine γ-lyase (ICSE), dlpropargylglycine (DPG) or β-cyanoalanine (BCA), and the nitric oxide (NO) synthase produce vasoconstriction and could be an alternative for the treatment of AS. The aim of this study was to demonstrate the ability of L-NAME, ICSE alone or in combination with 4-AP to restore blood pressure (BP) and improve survival in ovalbumin (OVA) rats AS. Experimental groups included non-sensitized Wistar rats (n = 6); AS (n = 6); AS (n = 10 per group) treated i.v. with 4-AP (AS+4-AP), epinephrine (AS+EPI), AS+DPG, AS+BCA, or with L-NAME (AS+L-NAME); or AS treated with drug combinations 4-AP+DPG, 4-AP+BCA, 4-AP+L-NAME, or 4-AP+EPI. AS was induced by i.v. OVA (1 mg). Treatments were administered i.v. one minute after AS induction. Mean arterial BP (MAP), heart rate (HR), and survival were monitored for 60 min. Plasma levels of histamine, prostaglandin E2 (PGE2) and F2 (PGF2α), leukotriene B4 and C4, angiotensin II, vasopressin, oxidative stress markers, pH, HCO3, PaO2, PaCO2, and K+ were measured. OVA induced severe hypotension and all AS rats died. Moreover, 4-AP, 4-AP+EPI, or 4-AP+BCA normalized both MAP and HR and increased survival. All sensitized rats treated with 4-AP alone or with 4-AP+BCA survived. The time-integrated MAP “area under the curve” was significantly higher after combined 4-AP treatment with ICSE. Metabolic acidosis was not rescued and NO, ICSE, and Kv inhibitors differentially alter oxidative stress and plasma levels of anaphylactic mediators. The AS-induced reduction of serum angiotensin II levels was prevented by 4-AP treatment alone or in combination with other drugs. Further, 4-AP treatment combined with EPI or with BCA also increased serum PGF2α, whereas only the 4-AP+EPI combination increased serum LTB4. Serum vasopressin and angiotensin II levels were increased by 4-AP treatment alone or in combination with other drugs. Moreover, 4-AP alone and in combination with inhibition of cystathionine γ-lyase or EPI normalizes BP, increases serum vasoconstrictor levels, and improves survival in the Wistar rat model of AS. These findings suggest possible investigative treatment pathways for research into epinephrine-refractory anaphylactic shock in patients.
Consensus statement on the epidemiology, diagnosis, prevention, and management of cow's milk protein allergy in the Middle East: a modifed Delphi‑based study
(2021) Al Hammadi, Suleiman
Background: This study aimed to develop an expert consensus regarding the epidemiology, diagnosis, and management of cow’s milk protein allergy (CMPA) in the Middle East. Methods: A three-step modifed Delphi method was utilized to develop the consensus. Fifteen specialized pediatricians participated in the development of this consensus. Each statement was considered a consensus if it achieved an agreement level of≥80%. Results: The experts agreed that the double-blind placebo-controlled oral challenge test (OCT) should be performed for 2–4 weeks using an amino acid formula (AAF) in formula-fed infants or children with suspected CMPA. Formula-fed infants with confrmed CMPA should be ofered a therapeutic formula. The panel stated that an extensively hydrolyzed formula (eHF) is indicated in the absence of red fag signs. At the same time, the AAF is ofered for infants with red fag signs, such as severe anaphylactic reactions. The panel agreed that infants on an eHF with resolved symptoms within 2–4 weeks should continue the eHF with particular attention to the growth and nutritional status. On the other hand, an AAF should be considered for infants with persistent symptoms; the AAF should be continued if the symptoms resolve within 2–4 weeks, with particular attention to the growth and nutritional status. In cases with no symptomatic improvements after the introduction of an AAF, other measures should be followed. The panel developed a management algorithm, which achieved an agreement level of 90.9%. Conclusion: This consensus document combined the best available evidence and clinical experience to optimize the management of CMPA in the Middle East.
A Novel Variant of the PIK3R1 Gene Mutation Associated With SHORT Syndrome and Agammaglobulinemia
(2024) Al Hammadi, Suleiman
Abstract: Primary immunodeficiencies are disorders of the immune system often caused by mutations of genes required for lymphocyte development. Phosphoinositide-3-kinase regulatory subunit 1 (PIK3R1) gene mutations are associated with SHORT syndrome, a rare multisystem disease. The name stands for Short stature, Hyperextensibility, Ocular depression, Rieger anomaly and Teething delay. Our case describes a child who presented with agammaglobulinemia with phenotypical features of SHORT syndrome. Upon further investigation, he was found to have a rare variant of the PIK3R1 gene mutation. This new mutation combines two distinct diseases with the same gene defect, which otherwise has been reported as two separate entities. The objective of this report is to identify a new gene mutation associated with SHORT syndrome along with agammaglobulinemia and to highlight the importance of recognizing the features of SHORT syndrome. We describe a nine-year-old male who presented with developmental delay and recurrent infections at the age of 12 months. Immunological evaluation revealed agammaglobulinemia and he has been scheduled for regular intravenous immunoglobulin replacement therapy. In view of characteristic syndromic physical features, speech and teething delay, we investigated further for the underlying genetic reason for agammaglobulinemia. The molecular analysis demonstrated a rare homozygous variant, c.244dup, in the PIK3R1 gene. This case reveals the association of the PIK3R1 gene mutation with agammaglobulinemia and SHORT syndrome. It further demonstrates the discovery of a new pathological variant of the gene. A detailed history and examination along with an immunological and genetic workup should be carried out for children with certain distinct phenotypical features. SHORT syndrome has specific characteristics that call for awareness and early recognition for prompt diagnosis and intervention. Emphasis is placed on genetic counseling as the disease is inherited in an autosomal recessive pattern, as demonstrated by molecular genetic studies.