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Chronic granulomatous disease. Diagnosis by the dihydrorhodamine assay
Diana Sanabria1, Vivian Giménez1, Celia Martínez de Cuéllar2
1Departamento de Inmunología, Instituto de Investigaciones en ciencias de la Salud, Universidad Nacional de Asunción, Paraguay.
Insights
The dihydrorhodamine (DHR) assay identified three pediatric Chronic Granulomatous Disease (CGD) cases and five carriers in Paraguay. This study provides crucial diagnostic information and insights into CGD inheritance patterns.
Area of Science:
- Immunology
- Genetics
- Pediatrics
Background:
- Chronic Granulomatous Disease (CGD) involves altered neutrophil oxidative function with X-linked and autosomal recessive inheritance patterns.
- The dihydrorhodamine (DHR) assay is a key diagnostic tool for CGD, carrier detection, and determining inheritance patterns.
Purpose of the Study:
- To diagnose CGD in children presenting with recurrent infections using the DHR assay.
- To evaluate female relatives for carrier status and elucidate inheritance patterns in suspected CGD cases.
Main Methods:
- The DHR assay was performed on 107 pediatric patients (<18 years) with suspected CGD and 6 female relatives.
- Neutrophil stimulation index (SI) was measured to assess DHR assay results.
Main Results:
- The DHR assay detected three CGD cases (two likely X-linked, one AR CGD) and identified five carriers among female relatives.
- A complete DHR shift was observed in 101/107 children, while 2/107 showed no shift and one had a slight shift.
Conclusions:
- The DHR assay successfully identified CGD cases and carriers, providing essential diagnostic information in Paraguay.
- This study marks the first use of the DHR assay in Paraguay for CGD diagnosis and carrier screening, offering insights into inheritance patterns.
Introduction:
Chronic granulomatous disease (CGD) is characterized by an alteration of the neutrophil oxidative function. Its inheritance patterns are linked to the X chromosome (X-linked CGD) and autosomal recessive (AR CGD). The dihydrorhodamine (DHR) assay is used for the diagnosis and detection of carriers and provides information on inheritance patterns.
Objective:
To detect CGD cases in chil dren with recurrent infections and to evaluate their female relatives through the DHR assay to iden tify carriers and obtain information about possible inheritance patterns.
Patients And Method:
107 patients (<18 years of age) with clinical suspicion of CGD such as pneumonia, lymphadenopathies, and abscesses were included, referred by physicians from public hospitals between 2014 and 2017. Six female relatives of children with CGD were also included. The DHR assay was performed on all patient samples and the results were expressed as neutrophils stimulation index (SI).
Results:
The median age of patients was 3 years and 62/107 of them were male. The average SI was 39.7±13.8 and a complete shift of DHR was found in 101/107 children. In 2/107 children, no DHR shift was observed (SI=1.0) indicating possible X-linked CGD, and a third child showed a slight DHR shift (SI=4.8) compatible with AR CGD. 5/6 female relatives presented a bimodal pattern, showing a carrier status.
Conclusions:
Three cases of CGD and five female carriers were detected through the DHR assay, being the first time that this technique was used in Paraguay. Information on the most likely inheri tance patterns, two X-linked CGD, and one AR CGD case was also obtained.
