Cystic fibrosis in Saudi Arabia: common and rare presentations

When is asthma not guilty?

Asthma is a common childhood condition. Its prevalence in Saudi Arabia is high, increasing, and could exceed 20% at the current trajectory. Asthma is a syndrome with different clinical presentations and phenotypes. Many conditions are often misdiagnosed as asthma because they share the same symptoms, particularly coughing and shortness of breath; physical findings, such as wheezing; radiological findings, such as hyperinflation on chest X-ray; or even responses to asthma therapies, as in some patients with bronchiolitis. When treating the younger age group (>5 years old), there should be a high degree of suspicion of alternative causes when evaluating patients presenting with clinical features suggestive of asthma or patients who do not respond well to asthma therapies. This study will highlight common conditions that may mimic asthma and, as a result of incorrect treatment, unnecessarily expose patients to steroids and other therapies for extended periods. Furthermore, we seek to alert healthcare providers to common symptoms and signs that suggest a cause other than asthma and suggest when to refer the patient to subspecialists.

Characteristics of electrolyte imbalance and pseudo-bartter syndrome in hospitalized cystic fibrosis children and adolescents

INTRODUCTION

Pseudo-Bartter syndrome (PBS) is a rare manifestation of Cystic fibrosis (CF) and can often be the initial presentation in these patients, however, due to significantly overlapping symptoms it is often misdiagnosed as simple dehydration or Bartter syndrome. The objective of our study was to highlight the key features of PBS and electrolyte imbalance in CF patients helping in early and prompt diagnosis.

METHOD

We performed a retrospective study from January 2015 to December 2019 at the Aga Khan University Hospital (AKUH), Pakistan. CF patients aged from 1-18 years, admitted at AKUH were enrolled and their laboratory data and individual charts were reviewed. Patients were categorized into three groups based on their serum electrolyte profile and their clinical findings were compared.

RESULT

We enrolled 72 CF patients, out of which 42 (58%) were categorized into the Normal Electrolyte (NE) group, 19 (26%) into the Electrolyte Imbalance (EI) group and 11 (15%) in the PBS group. Out of 11 cases, 6 (54.54%) patients in PBS group presented with features consistent with PBS leading to CF diagnosis labeled as "early presenters". Mean age of patients in the PBS group was 3.81± 0.86 years and their age at diagnosis were significantly lower as compared to other groups. Gastrointestinal disturbances including diarrhea, vomiting and constipation were more common in the EI and PBS groups. Polyuria was most common in the PBS (72%) group. Length of hospital stay showed no significant difference.

CONCLUSION

Pseudo-Bartter syndrome can be a presenting feature of cystic fibrosis. Electrolyte imbalance should be anticipated in hospitalized CF children and adolescent.

Demographic characteristics, clinical and laboratory features, and the distribution of pathogenic variants in the CFTR gene in the Cypriot cystic fibrosis (CF) population demonstrate the utility of a national CF patient registry

BACKGROUND

Specialized clinical care for cystic fibrosis (CF) in Cyprus, a small island country, has been implemented since the 1990s. However, only recently, a national CF patient registry has been established for the systematic recording of patients' data. In this study, we aim to present data on the epidemiological, genotypic and phenotypic features of CF patients in the country from the most recent data collection in 2019, with particular emphasis on notable rare or unique cases.

RESULTS

Overall, data from 52 patients are presented, 5 of whom have deceased and 13 have been lost to follow-up in previous years. The mean age at diagnosis was 7.2 ± 12.3 years, and the mean age of 34 alive patients by the end of 2019 was 22.6 ± 13.2 years. Patients most commonly presented at diagnosis with acute or persistent respiratory symptoms (46.2%), failure to thrive or malnutrition (40.4%), and dehydration or electrolyte imbalance (32.7%). Sweat chloride levels were diagnostic (above 60 mmol/L) in 81.8% of examined patients. The most common identified mutation was p.Phe508del (F508del) (45.2%), followed by p.Leu346Pro (L346P) (6.7%), a mutation detected solely in individuals of Cypriot descent. The mean BMI and FEV1 z-scores were 0.2 ± 1.3 and - 2.1 ± 1.7 across all age groups, respectively, whereas chronic Pseudomonas aeruginosa colonization was noted in 26.9% of patients. The majority of patients (74.5%) were eligible to receive at least one of the available CFTR modulator therapies. In 25% of patients we recovered rare or unique genotypic profiles, including the endemic p.Leu346Pro (L346P), the rare CFTR-dup2, the co-segregated c.4200_4201delTG/c.489 + 3A > G, and the polymorphism p.Ser877Ala.

CONCLUSIONS

CF patient registries are particularly important in small or isolated populations, such as in Cyprus, with rare or unique disease cases. Their operation is necessary for the optimization of clinical care provided to CF patients, enabling their majority to benefit from evolving advances in precision medicine.

Clinical features and accompanying findings of Pseudo-Bartter Syndrome in cystic fibrosis

BACKGROUND

Pseudo-Bartter syndrome (PBS) is a rare complication of cystic fibrosis (CF) and there are limited data in the literature about it. We aimed to compare clinical features and accompanying findings of patients with PBS in a large patient population.

METHODS

The data were collected from the Cystic Fibrosis Registry of Turkey where 1170 CF patients were recorded in 2017. Clinical features, diagnostic test results, colonization status, complications, and genetic test results were compared in patients with and without PBS.

RESULTS

Totally 1170 patients were recorded into the registry in 2017 and 120 (10%) of them had PBS. The mean age of diagnosis and current age of patients were significantly younger and newborn screening positivity was lower in patients with PBS (P < .001). There were no differences between the groups in terms of colonization status, mean z-scores of weight, height, BMI, and mean FEV₁ percentage. Types of genetic mutations did not differ between the two groups. Accompanying complications were more frequent in patients without PBS.

CONCLUSION

PBS was detected as the most common complication in the registry. It could be due to warm weather conditions of our country. It is usually seen in younger ages regardless of mutation phenotype and it could be a clue for early diagnosis of CF.

Assessment of Correlation between Sweat Chloride Levels and Clinical Features of Cystic Fibrosis Patients

INTRODUCTION

Cystic Fibrosis (CF) is an autosomal recessive disorder and the incidence of this disease is undermined in Northern India. The distinguishable salty character of the sweat belonging to individuals suffering from CF makes sweat chloride estimation essential for diagnosis of CF disease.

AIM

The aim of this prospective study was to elucidate the relationship of sweat chloride levels with clinical features and pattern of CF.

MATERIALS AND METHODS

A total of 182 patients, with clinical features of CF were included in this study for quantitative measurement of sweat chloride. Sweat stimulation and collection involved pilocarpine iontophoresis based on the Gibson and Cooks methodology. The quantitative estimation of chloride was done by Schales and Schales method with some modifications. Cystic Fibrosis Trans Membrane Conductance Regulator (CFTR) mutation status was recorded in case of patients with borderline sweat chloride levels to correlate the results and for follow-up.

RESULTS

Out of 182 patients having clinical features consistent with CF, borderline and elevated sweat chloride levels were present in 9 (5%) and 41 (22.5%) subjects respectively. Elevated sweat chloride levels were significantly associated with wheeze, Failure To Thrive (FTT), history of CF in Siblings, product of Consanguineous Marriage (CM), digital clubbing and steatorrhoea on univariate analysis. On multivariate analysis only wheeze, FTT and steatorrhoea were found to be significantly associated with elevated sweat chloride levels (p<0.05). Among the nine borderline cases six cases were positive for at least two CFTR mutations and rest of the three cases were not having any mutation in CFTR gene.

CONCLUSION

The diagnosis is often delayed and the disease is advanced in most patients at the time of diagnosis. Sweat testing is a gold standard for diagnosis of CF patients as genetic mutation profile being heterozygous and unlikely to become diagnostic test.

Sweat chloride concentrations in children with Idiopathic Nephrotic Syndrome

BACKGROUND

Idiopathic Nephrotic Syndrome (INS) has been believed to cause a false positive elevation of sweat chloride concentrations, as measured by the sweat test.

METHODS

Sweat tests were done for 11 children with acute onset INS at admission and again while they were in remission, with results being compared to normal historical controls.

RESULTS

The initial sweat chloride concentration for 10 patients was normal (mean16.7 ± 11.02 mmol/L) and 1 patient had inadequate collection. This latter patient and two others were excluded during follow-up because of diagnoses other than INS. Sweat test results for the eight INS patients during follow up remained unchanged when they were in remission (16.94 ± 7.88 mmol/L; P = 0.98; Wilcoxon Matched-Pairs Signed Rank Test). In comparing sweat chloride concentrations from INS patients to those from 20 historical control subjects, we found no significant differences (Mann-Whitney Test; initial vs. control P = 0.643; follow up vs. control P = 0.806).

CONCLUSIONS

INS does not cause a false positive sweat test. Further studies should be done to objectively assess the conditions that have been reported to affect sweat chloride concentrations.

Does meconium peritonitis pseudo-cyst obstruct labour?

Meconium peritonitis pseudo-cyst is very rare. Its perinatal management is controversial and can be associated with increased fetomaternal morbidity and mortality. A 34-week gestation infant with large meconium peritonitis pseudo-cyst, detected by intrapartum fetal ultrasound study, had abnormally increased ratio of fetal abdominal circumference to head circumference. Intrapartum aspiration of the pseudo-cyst was performed and was followed by a smooth vaginal delivery. The postnatal course of the baby showed that early laparotomy was essential for stabilisation of the infant's general condition.

Cystic fibrosis in Arabs: a prototype from Jordan

Cystic fibrosis is believed to be rare in Arabs. We report 202 cases (114 boys and 88 girls) diagnosed in Jordan over a period of 9 years. The mean age at diagnosis was 2.9 years. Classical presentation with growth failure, malabsorption and respiratory symptoms occurred in 75.4% of cases. Eighteen (10.8%) presented with hepatomegaly, 12 (7.2%) with meconium ileus and 11 (6.6%) had Pseudo-Bartter syndrome. Thirty-eight (23%) children died, most below the age of 1 year which may reflect a more severe disease in our population. Consanguineous marriage was present in 69% of cases. Genetic screening of 84 children and 66 parents revealed 24 different CFTR mutations with a DF508 mutation accounting for only 7.4%. Among the mutations detected, six were alleles identified for the first time. The fact that boys outnumber girls might reflect more deaths in girls due to the observed gender gap in CF mortality. It is possible that the low incidence of the DF508 mutation is due to a confounding effect and the high mortality in those carrying this mutation. The large number of different mutations reflects the ethnic diversity of the Jordanian population and the complex history of the country.

Cystic fibrosis in a large kindred family in Qatar

We describe 45 patients with cystic fibrosis (CF), diagnosed between June 1987 and May 1999, seen at the Hamad Medical Corporation, Qatar in the Arabian Gulf. Twenty-six of 32 families in the study were related and belonged to the same Bedouin tribe. The parents of 98% of these cases were consanguineous. Metabolic alkalosis and/or hypo-electrolytaemia were found in a large proportion of infants with CF. Cystic fibrosis in Qatari children is phenotypically variable with mild to moderate respiratory symptoms, and none of them died during this study. Among the non-Arabic-Asian patients, pulmonary symptoms were more severe, Pseudomonas colonization was earlier, pancreatic insufficiency occurred in infancy and four died in early life.

Geographic distribution of cystic fibrosis transmembrane regulator gene mutations in Saudi Arabia

A descriptive study was undertaken to characterize the cystic fibrosis transmembrane regulator gene mutations (CFTR) in the Saudi Arabian cystic fibrosis (CF) population in relation to clinical presentation and demographic and ethnic origin. During the period October 1992 to September 1997, 70 patients from 46 families were diagnosed as having CF, based on a typical clinical picture and sweat chloride levels > 60 mmol/l and were screened for CFTR mutations. Twelve mutations were identified in 34 families, which constitutes 70% of the CF alleles in the study group. Pancreatic insufficiency (PI) was found in the following mutations: 1548delG in exon 10 (15%) which occurred mainly in native Saudi patients in the central province; 3120 + 1G-->A in intron 16 (10%) and H139L in exon 4 (7%), found mainly in native Saudis from the eastern province; delta F508 mutation (13%) which occurred mainly in expatriates of Middle Eastern origin from different provinces; L117X in exon 19 (2%); G115X in exon 4 (2%); 711 + 1G-->A in intron 5 (2%); N 1303K in exon 21 (2%) and 425del42 in exon 4 (1%); I1234V in exon 19 (13%) with a predominance of nasal polyps and a variable degree of PI and lung disease; R553X in exon 11 (1%), with electrolyte imbalance; and S549R in 11 (2%) with pancreatic sufficiency and minimal pulmonary disease. The clinical picture did not differ significantly between patients of different ethnic origins with the same CFTR mutation.