A Decade Experience on Severe Combined Immunodeficiency Phenotype in Oman, Bridging to Newborn Screening

Current Status of Newborn Bloodspot Screening Worldwide 2024: A Comprehensive Review of Recent Activities (2020-2023)

Newborn bloodspot screening (NBS) began in the early 1960s based on the work of Dr. Robert "Bob" Guthrie in Buffalo, NY, USA. His development of a screening test for phenylketonuria on blood absorbed onto a special filter paper and transported to a remote testing laboratory began it all. Expansion of NBS to large numbers of asymptomatic congenital conditions flourishes in many settings while it has not yet been realized in others. The need for NBS as an efficient and effective public health prevention strategy that contributes to lowered morbidity and mortality wherever it is sustained is well known in the medical field but not necessarily by political policy makers. Acknowledging the value of national NBS reports published in 2007, the authors collaborated to create a worldwide NBS update in 2015. In a continuing attempt to review the progress of NBS globally, and to move towards a more harmonized and equitable screening system, we have updated our 2015 report with information available at the beginning of 2024. Reports on sub-Saharan Africa and the Caribbean, missing in 2015, have been included. Tables popular in the previous report have been updated with an eye towards harmonized comparisons. To emphasize areas needing attention globally, we have used regional tables containing similar listings of conditions screened, numbers of screening laboratories, and time at which specimen collection is recommended. Discussions are limited to bloodspot screening.

Immune Dysregulation in Monogenic Inborn Errors of Immunity in Oman: Over A Decade of Experience From a Single Tertiary Center

Background

Inborn errors of immunity (IEIs) are being recognized as an important cause of morbidity and mortality in communities with a high frequency of consanguinity, such as Oman, and thus recessively inherited conditions. Various monogenic causes of IEI have been recently discovered; however, the disease phenotype may be variable and does not always include infection at presentation, leading to a delay in diagnosis and a poor outcome. It is now well recognized that immune dysregulation manifestations are observed in a significant proportion of patients with IEI and occasionally precede infection.

Methods

Here, we retrospectively report the epidemiological, clinical, immunological, and molecular findings and outcomes from 239 patients with IEI who were diagnosed and managed at the Royal Hospital, Oman, from January 2010 to October 2021.

Results

The estimated annual cumulative mean incidence of IEI was 25.5 per 100,000 Omani live births with a total prevalence of 15.5 per 100,000 Omani population. Both the high incidence and prevalence are attributed to the high rate of consanguinity (78.2%). Defects affecting cellular and humoral immunity including severe combined immunodeficiency (SCID), combined immunodeficiency (CID), and CID with syndromic features were the predominant defects in IEI (36%). Immune dysregulation was a prominent manifestation and occurred in approximately a third of all patients with IEI (32%), with a mean age of onset of 81 months and a mean diagnostic delay of 50.8 months. The largest percentage of patients who showed such clinical signs were in the category of diseases of immune dysregulation (41%), followed by predominantly antibody deficiency (18%). The overall mortality rate in our cohort was 25.1%, with higher death rates seen in CID including SCID and diseases of immune dysregulation.

Conclusion

Immune dysregulation is a frequent manifestation of Omani patients with IEI. Early detection through raising awareness of signs of IEI including those of immune dysregulation and implementation of newborn screening programs will result in early intervention and improved overall outcome.

Bacillus Calmette-Guérin vaccine-related complications in children in Oman

BACKGROUND

Bacillus Calmette-Guérin (BCG) vaccine-related complications are frequently observed in children in Oman. There are a few regional studies on BCG complications, but none from Oman.

OBJECTIVE

Evaluate the spectrum of BCG-vaccine related complications and immune status in Omani children.

DESIGN

Retrospective cross-sectional study.

SETTING

Referral tertiary hospital.

METHODS

Children aged younger than 13 years old and with complications of BCG vaccination recorded from 2006-2018 were included in this study. Clinical characteristics, treatment, immune workup and outcome were reviewed from hospital records.

MAIN OUTCOME MEASURES

Different BCG vaccine-related complications categorized by the site of involvement.

SAMPLE SIZE

226.

RESULTS

Of the 226 children had BCG-vaccine related complications, 99% received BCG vaccine immediately after birth. The median age of presentation was 4 months. The most common complication was isolated BCG lymphadenitis (85%, n=192), followed by BCG-related osteomyelitis (10.2%, n=23) and disseminated BCG infection (4.9%, n=11). The median age of presentation of disseminated BCG was 5 months, with different organs involved. Out of 11 children with disseminated BCG infection, 72.7% (n=8) had primary immune deficiency (PID), including chronic granulomatous disease (CGD, n=5), severe combined immunodeficiency (SCID) (n=2); 1 patient had Mendelian susceptibility to mycobacterial disease (IFNGR2 deficiency); 2 patients with PID not yet identified and the 1 with a non-specific PID had blood or saliva samples sent for whole-exome sequencing.

CONCLUSION

Because of the spectrum of BCG vaccine-related complications, including the most severe in children with PID, we suggest that delaying the BCG vaccine from birth to 6 months may prevent disseminated BCG diseases and their complications in children with PID because any PID will have been identified before 6 months. Further studies are needed to guide this recommendation.

LIMITATIONS

Single center-based study that may not provide a full overview of all BCG vaccine-related complications in Oman. Unavailability of details of some microbiological results and an inability to determine the detailed management for all patients.

CONFLICT OF INTEREST

None.