Surfactant protein B deficiency: a rare cause of respiratory failure in a Lebanese newborn

Abstract

LettersSurfactant protein B deficiency: a rare cause of respiratory failure in a Lebanese newborn George Ferzli, Khalid A. Yunis, and Salman Mroueh George Ferzli Search for more papers by this author , Khalid A. Yunis Search for more papers by this author , and Salman Mroueh Search for more papers by this author Published Online::2 Feb 2006https://doi.org/10.5144/0256-4947.2006.69SectionsPDF ToolsAdd to favoritesDownload citationTrack citations ShareShare onFacebookTwitterLinked InRedditEmail AboutIntroductionTo the Editor: Respiratory diseases secondary to congenital surfactant proteins deficiency are increasingly recognized. To bring to the attention of pediatricians an unusual cause of neonatal respiratory disease, we report on a newborn with progressive respiratory disease due to surfactant protein B (SP-B) deficiency. To our knowledge, this is the first case of SP-B deficiency reported in the Middle East.The patient was a term female newborn delivered vaginally after an uneventful pregnancy to second-degree consanguineous parents. The mother had a stillbirth and a newborn that died on the second day of life of respiratory causes. Four other siblings are normal. Apgar scores were 5 and 8 at 1 and 5 minutes, respectively. The baby was hypotonic and required vigorous stimulation. Birth weight was 3250 grams. Physical examination was remarkable for tachypnea, cyanosis and bilateral decreased air entry. Chest X-ray showed bilateral fine granular infiltrates.The baby was started on antibiotics after a sepsis work up. She required conventional and then high frequency oscillatory ventilation because of hypoxemia and CO2 retention. Echocardiography showed mild right ventricular hypertrophy. On the fourth day of life, she received bovine surfactant (Survanta, Abbott Laboratories, Columbus, Ohio, USA) intratracheally with clinical and radiological improvement that was not sustained on four additional doses. She then received furosemide, hydrocortisone and inhaled nitric oxide with no response. On the seventeenth day of life, she died of persistent hypoxemia with severe respiratory acidosis. Tracheal effluent collected before surfactant administration revealed complete absence of SP-B (Courtesy of Dr. Jeffrey Whitsett, Cincinnati Children’s Hospital). DNA analysis revealed the homozygous 122delT mutation, while both parents were heterozygous for the same mutation (Courtesy of Dr. Lawrence Nogee, Johns Hopkins University).SP-B is a hydrophobic protein involved in the adsorption of surfactant phospholipids to the air-liquid interface. It is coded by a gene of 11 exons on chromosome 2. In 1993, Nogee et al reported SP-B deficiency causing severe respiratory disease, as described in our patient.1 The patient and a sibling who had died earlier had a frame-shift mutation caused by a 2 base-pair insertion (121ins2) in exon 4 of the SP-B gene.2 Radiologically, SP-B deficiency presents like hyaline membrane disease. Histopathologically, the distal airspaces appear filled with lipid-rich, periodic acid Schiff-positive, eosinophilic proteinaceous material.1The diagnosis is established by failing to identify SP-B in the tracheal effluent and is confirmed by genetic studies, which show a mutation on the SP-B gene. More than 13 mutations have been described,3 of which (121ins2) accounts for about 70%. Its frequency in the United States is estimated to be 1 per 1000–3000 individuals.4 The 1043ins3 mutation was detected in 2 unrelated Pakistani families.3 The mutation described in the present report (122delT) was described in a consanguineous kindred of Kurdish descent,5 and in three unrelated Lebanese families (L. Nogee, personal communication). The recognition of specific mutations in various ethnic groups may allow diagnosis in individual patients and population-wide studies for the determination of gene frequency. This would gain particular importance in our population, where consanguinity is prevalent. SP-B deficiency is usually fatal, unless treated with lung transplantation.6 Gene transfer therapy may be the treatment modality of the future.Figure 1 Chest x-ray showing bilateral fine granular infiltrates.Download FigureARTICLE REFERENCES:1. Nogee LM, deMello DE, Dehner LP, Colten HR. "Pulmonary Surfactant Protein B deficiency in congenital pulmonary alveolar proteinosis" . N Eng J Med. 1993; 328:406-410. Google Scholar2. Nogee LM, Garnier G, Dietz HC, Singer L, Murphy AM, deMello DE, et al. "A mutation in the surfactant protein B gene responsible for fatal neonatal disease in multiple kindreds" . J Clin Invest. 1994; 93:1860-1863. Google Scholar3. Nogee LM, Wert SE, Profitt SA, Hull WM, Whitsett JA. "Allelic heterogeneity in hereditary Surfactant Protein B deficiency" . Am J Respir Crit Care Med. 2000; 161:973-981. Google Scholar4. Cole SF, Hamvas A, Rubinstein P, King E, Trusgnich M, Nogee LM, et al. "Brief report: population-based estimates of surfactant protein B deficiency" . Pediatrics. 2000; 105:538-541. Google Scholar5. Wallot M, Wagenvoort C, deMello D, Muller K-M, Floros J, Roll C. "Congenital alveolar proteinosis caused by a novel mutation of the surfactant protein B gene and misalignment of lung vessels in consanguineous kindred infants" . Eur J Pediatr. 1999; 158:513-518. Google Scholar6. Hamwas A, Nogee LM, Mallory GB, Spray TL, Huddleston CB, August A, Colten HR. "Lung transplantation for treatment of infants with surfactant protein B deficiency" . J Pediatr. 1997; 130:231-239. Google Scholar Previous article Next article FiguresReferencesRelatedDetails Volume 26, Issue 1January-February 2006 Metrics History Published online2 February 2006 InformationCopyright © 2006, Annals of Saudi MedicineThis work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.PDF download