Background
Omenn syndrome (MIM 603554) is an autosomal recessive form of severe combined immunodeficiency (SCID) characterized by erythroderma, desquamation, alopecia, chronic diarrhea, failure to thrive, lymphadenopathy, and hepatosplenomegaly (see the image below).
A unique dermatitis characterizes Omenn syndrome. The dermatitis initially resembles eczema, but with a pachydermia, as observed here. The lesions progress to desquamation. Failure to thrive is evident. This infant weighed 6 pounds at age 6 months; his weight had not changed since birth. Patients develop fungal, bacterial, and viral infections typical of SCID. In this syndrome, the SCID is associated with the virtual absence of B cells and the presence of oligoclonal autoreactive T cells.[1] Lymphocytosis results from the expansion of an oligoclonal population of activated and antigen-stimulated T helper 2 (TH 2) cells that produce elevated levels of interleukin 4 (IL-4) and interleukin 5 (IL-5). The latter cytokines mediate eosinophilia and elevated immunoglobulin E (IgE) levels (see the image below).
Common viral infections are fatal in severe combined immunodeficiency (SCID). This female infant died before bone marrow stem cell engraftment could occur, when varicella became resistant to acyclovir. The nasal bridge reveals superinfection with Klebsiella pneumoniae. Lymphedema, a characteristic of Omenn syndrome, is also shown. Pathophysiology
Early recognition of this condition is important for genetic counseling and early treatment.[2] The inflammation may be triggered by clonally expanded T cells, predominantly of the Th2 type.[3] These abnormal T cells presumably secrete cytokines that promote autoimmune as well as allergic inflammation. Omenn syndrome has been identified in leaky SCIDs caused by hypomorphic mutations in recombinase genes RAG-1 and RAG-2, which impair but do not eliminate recombination of variable, diversity, and joining (VDJ) segments of TCR and Ig genes. Most cases of Omenn syndrome reported so far are associated with hypomorphic mutations in RAG-1/RAG-2 genes.
The inability to productively rearrange VDJ regions in T-cell and B-cell receptors leads to abnormal T cells and absent B cells. The mutations in RAG-1 and RAG-2 in Omenn syndrome differ from T-cell negative (T-), B-cell negative (B-), and natural killer cell positive (NKC+) SCID caused by RAG-1 or RAG-2 mutations. In these conditions, the mutations affect the active core of the recombinase genes and typically negate the production of the recombinase protein; hence, no development of T and B lineage cells occurs. In Omenn syndrome, the mutated RAG-1 and RAG-2 proteins remain normally distributed in the nucleus of cells.
A novel mechanism has been suggested: by selectively impairing recombination at certain coding flanks, a RAG mutant can cause primary repertoire restriction, as opposed to a more random, limited repertoire that develops secondary to severely diminished recombination activity, with autoimmune manifestations related to decreased thymic expression of tissue-specific antigens.[4]
However, Omenn syndrome is now known to occur in other leaky SCIDs with mutations in the RNA component of mitochondrial RNA processing endoribonuclease, adenosine deaminase, interleukin 2 (IL-2) receptor gamma, interleukin 7 (IL-7) receptor alpha, the nuclease ARTEMIS, and DNA ligase 4. Thus, Omenn syndrome is a distinct inflammatory process that can be associated with genetically diverse, leaky SCIDS. Accordingly, Omenn syndrome is best viewed, not as a specific form of SCID, but rather as an aberrant inflammatory condition that can be associated with multiple genetic abnormalities, which can significantly impair (but not abolish) T-cell development in the thymus. Mutations in the DCLRE1C gene, which encodes ARTEMIS, have been described in a number of patients.[5, 6] Many of the mutations were gross deletions of exons 1-3 or exons 1-4.
An oligoclonal expansion of Th2 population is viewed as a result of increased exposure to inadequately cleared antigens. These oligoclonal T cells have a highly restricted receptor repertoire, as well as increased apoptosis due to overexpression of CD95 and underexpression of anti-apoptotic factors, such as bcl -2.
Germinal centers are absent in the lymph nodes, which is consistent with the inability to produce functional antibodies. Hassall corpuscles are poorly formed, and lymphocytes are deficient in the thymus. Paracortical lymphocytes are absent in the spleen.
RAG -deficient mice have been developed. Their defects are restricted to the T- B- immunologic abnormalities, as observed in human RAG deficiency. Recently, 2 murine models bearing mutations of the VDJ recombinase analogous to those causing human OS have been developed. These murine models have oligoclonal T cells, an absence of circulating B cells, peripheral eosinophilia, and activated autoreactive T cells infiltrating gut and skin, causing diarrhea, alopecia, and, in some cases, severe erythrodermia.[7, 8]
Epidemiology
Frequency
United States
The frequency of Omenn syndrome is difficult to ascertain. The prevalence of all forms of SCID is estimated to be 1 case per 50,000 population.
International
Omenn syndrome has been reported in patients from throughout the world, mainly North America and Europe.
Mortality/Morbidity
Omenn syndrome is fatal if untreated. Patients have life-threatening viral, bacterial, fungal, and Pneumocystis carinii infections that are observed in other types of SCID. Patients commonly have Staphylococcus aureus sepsis, which is related to the generalized dermatitis. Live viral infections, including those due to attenuated oral poliovirus, may cause death. In addition, chronic diarrhea and resulting inanition may be responsible for death.
Bone marrow transplantation (BMT) is usually successful, but life-threatening acute or chronic graft versus host disease (GVHD) may be a complication. This can occur in any stem cell reconstitution procedure.
Race
Patients have been identified in the United States, Canada, Europe, and India.
Sex
The incidences are equal among male and female infants; this observation is consistent with the autosomal recessive etiology of Omenn syndrome.
Age
Infants present within weeks of birth and usually by age 3 months, as do those with other types of SCID. The characteristic dermatitis, chronic diarrhea, and failure to thrive often precede the onset of infections. Published reports of patients describe presentation by the time the patient is aged 6 months.
Couëdel C, Roman C, Jones A, Vezzoni P, Villa A, Cortes P. Analysis of mutations from SCID and Omenn syndrome patients reveals the central role of the Rag2 PHD domain in regulating V(D)J recombination. J Clin Invest. Apr 2010;120(4):1337-44. [Medline]. [Full Text].
Jaouad IC, Ouldim K, Ali Ou Alla S, Kriouile Y, Villa A, Sefiani A. Omenn syndrome with mutation in RAG1 gene. Indian J Pediatr. Sep 2008;75(9):944-6. [Medline].
Villa A, Notarangelo LD, Roifman CM. Omenn syndrome: Inflammation in leaky severe combined immunodeficiency. J Allergy Clin Immunol. Dec 2008;122(6):1082-6. [Medline].
Wong SY, Lu CP, Roth DB. A RAG1 mutation found in Omenn syndrome causes coding flank hypersensitivity: a novel mechanism for antigen receptor repertoire restriction. J Immunol. Sep 15 2008;181(6):4124-30. [Medline].
Pannicke U, Hönig M, Schulze I, Rohr J, Heinz GA, Braun S, et al. The most frequent DCLRE1C (ARTEMIS) mutations are based on homologous recombination events. Hum Mutat. Feb 2010;31(2):197-207. [Medline].
Mancebo E, Recio MJ, Martinez-Busto E, et al. Possible role of Artemis c.512C>G polymorphic variant in Omenn syndrome. DNA Repair (Amst). Jan 2 2011;10(1):3-4. [Medline].
Marrella V, Poliani PL, Casati A, et al. A hypomorphic R229Q Rag2 mouse mutant recapitulates human Omenn syndrome. J Clin Invest. May 2007;117(5):1260-9. [Medline].
Khiong K, Murakami M, Kitabayashi C, et al. Homeostatically proliferating CD4 T cells are involved in the pathogenesis of an Omenn syndrome murine model. J Clin Invest. May 2007;117(5):1270-81. [Medline].
Gozdzik J, Czogala W, Skoczen S, et al. Rapid full engraftment and successful immune reconstitution after allogeneic hematopoietic stem cell transplantation with reduced intensity conditioning in Omenn syndrome. Pediatr Transplant. Oct 25 2008;[Medline].
Schonberger S, Ott H, Gudowius S, et al. Saving the red baby: Successful allogeneic cord blood transplantation in Omenn syndrome. Clin Immunol. Dec 7 2008;[Medline].
Garcia-Lloret M, McGhee S, Chatila TA. Immunoglobulin replacement therapy in children. Immunol Allergy Clin North Am. Nov 2008;28(4):833-49. [Medline].
Siegel J. The product: All intravenous immunoglobulins are not equivalent. Pharmacotherapy. Nov 2005;25(11 Pt 2):78S-84S. [Medline].
Shah S. Pharmacy considerations for the use of IGIV therapy. Am J Health Syst Pharm. Aug 15 2005;62(16 Suppl 3):S5-11. [Medline].
Hooper JA. Intravenous immunoglobulins: evolution of commercial IVIG preparations. Immunol Allergy Clin North Am. Nov 2008;28(4):765-78, viii. [Medline].
Brown L, Xu-Bayford J, Allwood Z, et al. Neonatal diagnosis of severe combined immunodeficiency leads to significantly improved survival outcome: the case for newborn screening. Blood. Mar 17 2011;117(11):3243-6. [Medline].
Aleman K, Noordzij JG, de Groot R, et al. Reviewing Omenn syndrome. Eur J Pediatr. Dec 2001;160(12):718-25. [Medline].
Brooks EG, Filipovich AH, Padgett JW, Mamlock R, Goldblum RM. T-cell receptor analysis in Omenn's syndrome: evidence for defects in gene rearrangement and assembly. Blood. Jan 1 1999;93(1):242-50. [Medline].
Brugnoni D, Airo P, Facchetti F, et al. In vitro cell death of activated lymphocytes in Omenn's syndrome. Eur J Immunol. Nov 1997;27(11):2765-73. [Medline].
Chan A, Scalchunes C, Boyle M, Puck JM. Early vs. delayed diagnosis of severe combined immunodeficiency: a family perspective survey. Clin Immunol. Jan 2011;138(1):3-8. [Medline]. [Full Text].
Chilosi M, Facchetti F, Notarangelo LD, et al. CD30 cell expression and abnormal soluble CD30 serum accumulation in Omenn's syndrome: evidence for a T helper 2-mediated condition. Eur J Immunol. Feb 1996;26(2):329-34. [Medline].
Lacy CF, Armstrong LL, Goldman MP, Lance LL (Editors). Drug Information Handbook 2008-2009. 16th edition. Cleveland, Ohio: Lexi-Comp, Inc; 2008.
Ege M, Ma Y, Manfras B, et al. Omenn syndrome due to ARTEMIS mutations. Blood. Jun 1 2005;105(11):4179-86. [Medline]. [Full Text].
Gennery AR, Hodges E, Williams AP, et al. Omenn's syndrome occurring in patients without mutations in recombination activating genes. Clin Immunol. Sep 2005;116(3):246-56. [Medline].
Giliani S, Bonfim C, de Saint Basile G, et al. Omenn syndrome in an infant with IL7RA gene mutation. J Pediatr. Feb 2006;148(2):272-4. [Medline].
Gomez L, Le Deist F, Blanche S, et al. Treatment of Omenn syndrome by bone marrow transplantation. J Pediatr. Jul 1995;127(1):76-81. [Medline].
Gruber TA, Shah AJ, Hernandez M, et al. Clinical and genetic heterogeneity in Omenn syndrome and severe combined immune deficiency. Pediatr Transplant. Sep 15 2008;[Medline].
Grunebaum E, Bates A, Roifman CM. Omenn syndrome is associated with mutations in DNA ligase IV. J Allergy Clin Immunol. Dec 2008;122(6):1219-20. [Medline].
Mazzolari E, Moshous D, Forino C, et al. Hematopoietic stem cell transplantation in Omenn syndrome: a single-center experience. Bone Marrow Transplant. Jul 2005;36(2):107-14. [Medline].
Omenn GS. Familial reticuloendotheliosis with eosinophilia. N Engl J Med. Aug 19 1965;273:427-32. [Medline].
Rieux-Laucat F, Bahadoran P, Brousse N, et al. Highly restricted human T cell repertoire in peripheral blood and tissue-infiltrating lymphocytes in Omenn's syndrome. J Clin Invest. Jul 15 1998;102(2):312-21. [Medline]. [Full Text].
Santagata S, Villa A, Sobacchi C, et al. The genetic and biochemical basis of Omenn syndrome. Immunol Rev. Dec 2000;178:64-74. [Medline].
Schwartz SA. Intravenous immunoglobulin treatment of immunodeficiency disorders. Pediatr Clin North Am. Dec 2000;47(6):1355-69. [Medline].
Signorini S, Imberti L, Pirovano S, et al. Intrathymic restriction and peripheral expansion of the T-cell repertoire in Omenn syndrome. Blood. Nov 15 1999;94(10):3468-78. [Medline]. [Full Text].
Thampakkul S, Ballow M. Replacement intravenous immune serum globulin therapy in patients with antibody immune deficiency. Immunol Allergy Clin North Am. 2001;21(1):165. [Full Text].
Tomizawa D, Aoki Y, Nagasawa M, et al. Novel adopted immunotherapy for mixed chimerism after unrelated cord blood transplantation in Omenn syndrome. Eur J Haematol. Nov 2005;75(5):441-4. [Medline].
Villa A, Santagata S, Bozzi F, et al. Partial V(D)J recombination activity leads to Omenn syndrome. Cell. May 29 1998;93(5):885-96. [Medline].
| Brand(Manufacturer) | Manufacturing Process | pH | Additives (IVIG products containing sucrose are more often associated with renal dysfunction, acute renal failure, and osmotic nephrosis, particularly with preexisting risk factors [eg, history of renal insufficiency, diabetes mellitus, age >65 y, dehydration, sepsis, paraproteinemia, nephrotoxic drugs].) | Parenteral Form and Final Concentrations | IgA Content (mcg/mL) |
| Carimune NF (CSL Behring) | Kistler-Nitschmann fractionation; pH 4 incubation, nanofiltration | 6.4-6.8 | 6% solution: 10% sucrose, < 20 mg NaCl/g protein | Lyophilized powder 3%, 6%, 9%, 12% | Trace |
| Flebogamma (Grifols USA) | Cohn-Oncley fractionation, PEG precipitation, ion-exchange chromatography, pasteurization | 5.1-6 | Sucrose free, contains 5% D-sorbitol | Liquid 5% | < 50 |
| Gammagard Liquid 10% (Baxter Bioscience) | Cohn-Oncley cold ethanol fractionation, cation and anion exchange chromatography, solvent detergent treated, nanofiltration, low pH incubation | 4.6-5.1 | 0.25M glycine | Ready-for-use Liquid 10% | 37 |
| Gamunex (Talecris Biotherapeutics) | Cohn-Oncley fractionation, caprylate-chromatography purification, cloth and depth filtration, low pH incubation | 4-4.5 | Contains no sugar, contains glycine | Liquid 10% | 46 |
| Gammaplex (Bio Products) | Solvent/detergent treatment targeted to enveloped viruses; virus filtration using Pall Ultipor to remove small viruses including nonenveloped viruses; low pH incubation | 4.8-5.1 | Contains sorbitol (40 mg/mL); do not administer if fructose intolerant | Ready-for-use solution 5% | < 10 |
| Iveegam EN (Baxter Bioscience) | Cohn-Oncley fraction II/III; ultrafiltration; pasteurization | 6.4-7.2 | 5% solution: 5% glucose, 0.3% NaCl | Lyophilized powder 5% | < 10 |
| Polygam S/D Gammagard S/D (Baxter Bioscience for the American Red Cross) | Cohn-Oncley cold ethanol fractionation, followed by ultracentrafiltration and ion exchange chromatography; solvent detergent treated | 6.4-7.2 | 5% solution: 0.3% albumin, 2.25% glycine, 2% glucose | Lyophilized powder 5%, 10% | < 1.6 (5% solution) |
| Octagam (Octapharma USA) 9/24/10: Withdrawn from market because of unexplained reports of thromboembolic events | Cohn-Oncley fraction II/III; ultrafiltration; low pH incubation; S/D treatment pasteurization | 5.1-6 | 10% maltose | Liquid 5% | 200 |
| Panglobulin (Swiss Red Cross for the American Red Cross) | Kistler-Nitschmann fractionation; pH 4, trace pepsin, nanofiltration | 6.6 | Per gram of IgG: 1.67 g sucrose, < 20 mg NaCl | Lyophilized powder 3%, 6%, 9%, 12% | 720 |
| Privigen Liquid 10% (CSL Behring) | Cold ethanol fractionation, octanoic acid fractionation, and anion exchange chromatography; pH 4 incubation and depth filtration | 4.6-5 | L-proline (approximately 250 mmol/L) as stabilizer; trace sodium; does not contain carbohydrate stabilizers (eg, sucrose, maltose) | Ready-for use liquid 10% | < 25 |

