Complement and antibody primary immunodeficiency in juvenile systemic lupus erythematosus patients.

OBJECTIVE: To evaluate the frequency of primary immunodeficiencies (PID) in juvenile systemic lupus erythematosus (JSLE) patients. METHODS: Some 72 JSLE patients were analyzed for levels of immunoglobulin classes and IgG subclasses and early components of the classical complement pathway. Determination of C4 gene copy number (GCN) and detection of type I C2 deficiency (D) were also performed. RESULTS: PID was identified in 16 patients (22%): C2D in three, C4D in three, C1qD in two, IgG2D (<20 mg/dl) in four, IgAD (<7 mg/dl) in three, and IgMD (<35 mg/dl) in three; one of these patients presented IgA, C2 and C4D. Two patients had low C4 GCN and two had type I C2D. Demographic data, family history of autoimmune disease and PID, JSLE clinical findings, occurrence of infections, disease activity and therapies were similar in patients with and without PID (p > 0.05). Remarkably, the median of Systemic Lupus International Collaborating Clinics/ACR-damage index (SLICC/ACR-DI) was significantly higher in JSLE patients with PID compared with patients without these abnormalities (p = 0.0033), likewise the high frequency of SLICC/ACR-DI > 1 (p = 0.023). CONCLUSIONS: A high frequency of PID was observed in JSLE patients, suggesting that these defects may contribute to lupus development. Our findings indicate that these two groups of PID should be investigated in severe pediatric lupus.

Case report: diffuse plane xanthoma with low C4 and systemic inflammatory symptoms.

A normolipemic patient with diffuse plane xanthomas, IgG monoclonal gammopathy of unknown significance, low levels of C4, and systemic inflammatory symptoms is presented. Delay from disease onset to diagnosis is discussed.

[Hereditary angioedema. A report of a case and literature review]. / Angioedema hereditario. Comunicación de un caso y revisión de la bibliografía.

Hereditary angioedema is a congenital disorder with recurrent attacks of localized swelling of submucosal and subcutaneous tissue, or both caused by a deficiency of the plasma protein C1 inhibitor. It is caused by heterozygous defects in the C1 inhibitor gene located on chromosome 11q, and it has an autosomal dominant inheritance pattern. This disease afflicts 1 in 10,000 to 1 in 150,000 persons. Hereditary angioedema has been reported in all races, and no sex predominance has been found. Skin and visceral organs may be involved by the typically massive local edema. The most commonly involved viscera are the respiratory and gastrointestinal systems, and it can affect the upper airways resulting in severe life-threatening symptoms, including the risk of asphyxiation. There are three types of hereditary angioedema, which difference lies in the inheritance pattern and in the C1 esterase inhibitor and C4 concentrations. The treatment is complicated and it should be treated with intravenous purified C1 inhibitor concentrate; corticosteroids, antihistamines and epinephrine can be useful adjuncts but they are not effective. We report a patient with hereditary angioedema type 1 and make a review of the medical literature.

[Atypical presentation of hereditary angioedema. A report of a case and literature review]. / Manifestación atípica de angioedema hereditario. Comunicación de un caso y revisión de la literatura.

Hereditary angioedema is an uncommon disorder mainly caused by defects of the gene for C1 inhibitor. These patients present recurrent edema episodes in the different regions of the body, including larynx edema in some cases. Low plasma levels of C1 inhibitor confirm the diagnosis. It is important to establish an early diagnosis and prompt treatment to this disorder due to its potential of fatal consequences and multiple alterations in the quality of life that have been associated with. The indicated treatment is substitutive therapy of C1 inhibitor concentrate. We present the case of a patient a 27 year-old female with a history of seven years of evolution, with daily periorbital, upper and lower extremities and labial edema episodes who was classified as C1 inhibitor deficiency type II. She began treatment with attenuated androgens in progressive increased doses with poor response, appearing torpid evolution without a favorable response. This case corresponds to a very atypical presentation of C1 inhibitor deficiency with daily symptoms, unlike the typical intermittent course of the classic disease.

Complement and IgG subclasses in agammaglobulinemic patients.

Complement and IgG subclass analysis was performed in six agammaglobulinemic patients suffering from recurrent bacterial infections. Complement analysis included functional activity of the classical (CH50) and the alternative pathway (APH50) of complement, the complement proteins C3, C4, factor B, the regulators C1-inhibitor, factors H and I as well as the C3-derived split product C3dg/C3d. Plasma concentrations of total IgG ranged between < 0.01 and 297 mg/dl. IgM and IgA were almost undetectable. Levels of all IgG subclasses, which in most cases were measurable only by sensitive ELISA, were markedly reduced in all patients. A pronounced activation of the complement system was observed in all patients as revealed by reduced titers of hemolytic function and elevated levels of C3dg/C3d. Despite the fact that complement activation by itself was the major reason for decreased C4 levels, from depressed plasma concentrations of the common allotypic variants C4A and C4B, a heterozygous C4 deficiency could not be excluded in 2/6 patients. Our data clearly show that, by application of sensitive analytical methods, agammaglobulinemic patients vary considerably in their ability to synthesize immunoglobulins. This may, at least in part, explain the heterogeneous pattern of clinical symptoms. The increased susceptibility of agammaglobulinemic patients to bacterial infections is reflected by a highly activated, and thereby depleted complement system.

Hereditary angioedema type II--a study of two families.

Hereditary angioedema (HA) is caused by a quantitative or qualitative deficiency of C1 esterase inhibitor (C1 INH). We present a study of nine patients with HA belonging to two different families. The symptoms started before 10 years of age in most cases (78%). Facial edema (lips, eyes) and of the extremities (feet, hands) were the most frequent complaints. Three patients presented edema of the glottis and one of them underwent a tracheostomy twice. Laboratory tests, outside the acute crisis, revealed low levels of C4 in all patients. The serum levels of C1 INH were normal in seven patients; however, functional activity was not observed in any of them. After the use of a modified androgen (danazol), control of symptoms was observed in all patients, although functional activity was re-established in only five patients.

Regional variation in C4 phenotype in patients with IgA nephropathy.

The relationship between complete deficiency for either isotype of the fourth component of complement, C4A or C4B, and glomerulonephritis was initially examined in white patients from Kentucky with either IgA nephropathy or Schönlein-Henoch purpura. Subsequently, C4B deficiency was found to be associated with IgA nephropathy for pediatric patients followed in Cincinnati, Ohio. We later reported that at least 60% of the original patients from Kentucky were related to at least one other patient with the disease. This finding raised the possibility that the C4 phenotype frequencies for these patients may have been biased by the fact that they were based on a sample of related patients. In our study, C4 phenotyping was performed for 52 related and 63 unrelated patients from Kentucky, 81 unrelated patients from the Mid-South region of the United States, and 39 unrelated patients from the Puglia region of southeastern Italy. In addition, data from patients with IgA nephropathy from Spain were available for comparative studies. Neither C4A deficiency nor C4B deficiency was significantly increased for groups of unrelated patients from the Mid-South, Italy, Spain, or Kentucky in comparison with regional control subjects. In fact, C4A and C4B deficiencies did not occur in any of the Italian patients. With the exception of C4A.6, frequencies for the most common C4A and C4B alleles did not differ among the unrelated patient and control groups from Kentucky and the Mid-South. In addition, no significant differences in C4A and C4B allelic frequencies were observed in comparisons of pediatric patients (diagnostic biopsy before age 18 years) and adult patients with IgA nephropathy in either U.S. population. Italian control subjects had a significantly lower frequency for C4A null alleles in comparison with control subjects from both Kentucky and the Mid-South; a significantly higher frequency of C4B null alleles was found among Kentucky control subjects than in Mid-South, Italian, and Spanish control samples. The importance of recognizing the ethnic background of study subjects and of eliciting a good family history to minimize unsuspected sampling of related patients should be considered in future disease association studies.

Atypical hypocomplementemic vasculitis syndrome in a child.

We report a patient who developed recurrent urticaria and angioedema at age 2 years, severe hypocomplementemic glomerulonephritis at 11 years, and end-stage renal disease at 14 years. His disease resembled the hypocomplementemic vasculitis syndrome but was atypical in its early age of presentation, severe hypocomplementemia, and progression to end-stage renal disease. Serum C1q levels were extremely low, and C4, C2, C3, and C5 levels were significantly reduced. Serum C1 inhibitor (C1INH) levels were slightly low, presumably from consumption. Circulating C1INH-C1r-C1s complexes were evidenced by reduced ratios of functional to antigenic C1INH and antigenic C1r to C1s. Family members had normal functional and antigenic levels of all complement components studied. The patient's serum, erythrocytes, platelets, and mononuclear cells did not activate complement when mixed with normal target serum. Absence of a circulating complement activator and the low serum C3 and C5 levels suggested the presence of a solid-phase complement activator, possibly related to renal or systemic vascular endothelium. As in patients with homozygous deficiencies of classical pathway components, a severe, prolonged, acquired C1q deficiency may have predisposed this patient to the development of glomerulonephritis.

Urticaria vasculítica: angioedema adquirido y enfermedad tiroidea autoinmune / Vasculitic urticaria: acquired angioedema and autoimmune thyroid disease

Se estudia un caso de urticaria vasculítica y deficiente adquirida del inhibidor de C1 en una paciente con historia personal y familiar de enfermedad de Graves que presenta poliquistosis ovárica. La deficiencia no es confirmada en sus familiares, es transitoria al igual que la disminución de C4 y presencia de complejos inmunes circulantes y se halla FAN + 1/250. Se cree que ambos cuadros se vinculan a la alteración inmune de la paciente, ya que la función tiroidea estaba normalizada al comenzar los brotes, y se menciona la probable acción beneficiosa de la indometacina y el antiestrógeno en la remisión clínica de ambas afecciones sin descartar la remisión espontánea

Urticaria vasculítica: angioedema adquirido y enfermedad tiroidea autoinmune / Vasculitic urticaria: acquired angioedema and autoimmune thyroid disease

Se estudia un caso de urticaria vasculítica y deficiente adquirida del inhibidor de C1 en una paciente con historia personal y familiar de enfermedad de Graves que presenta poliquistosis ovárica. La deficiencia no es confirmada en sus familiares, es transitoria al igual que la disminución de C4 y presencia de complejos inmunes circulantes y se halla FAN + 1/250. Se cree que ambos cuadros se vinculan a la alteración inmune de la paciente, ya que la función tiroidea estaba normalizada al comenzar los brotes, y se menciona la probable acción beneficiosa de la indometacina y el antiestrógeno en la remisión clínica de ambas afecciones sin descartar la remisión espontánea (AU)