MicroRNAs correlate with bacillary index and genes associated to cell death processes in leprosy

Mycobacterium leprae infects skin and peripheral nerves causing a broad of clinical forms. MicroRNAs (miRNAs) control immune mechanisms such as apoptosis, autophagy as well as to target genes leading to abnormal proliferation, metastasis, and invasion of cells. Herein we evaluated miRNAs expression for leprosy phenotypes in biopsies obtained from patients with and without reactions. We also correlated those miRNAs with both, bacillary index (BI) and genes involved in the micobacteria elimination process. Our results show a significant increase in the miR-125a-3p expression in paucibacillary (PB) patients vs multibacillary (MB) subjects (p = 0.007) and vs reversal reactions (RR) (p = 0.005), respectively. Likewise, there was a higher expression of miR-125a-3p in patients with erythema nodosum leprosum (ENL) vs MB without reactions (p = 0.002). Furthermore, there was a positive correlation between miR-125a-3p, miR-146b-5p and miR-132-5p expression and BI in patients with RR and ENL. These miRNAS were also correlated with genes such as ATG12 (miR-125a-3p), TNFRSF10A (miR-146b-5p), PARK2, CFLAR and STX7 (miR-132-5p). All together we underpin a role for these miRNAs in leprosy pathogenesis, implicating mechanisms such as apoptosis and autophagy in skin. The miR-125a-3p might have a distinct role associated with PB phenotype and ENL in MB patients.

Causal relationship between inflammatory bowel disease and erythema nodosum: A two-sample bidirectional Mendelian randomization study

BACKGROUND

Previous studies have demonstrated the coexistence of erythema nodosum (EN) and inflammatory bowel disease (IBD), while the exact etiology of the co-occurrence of the two disorders remains uncertain.

METHODS

A bidirectional two-sample Mendelian randomization (MR) design was employed to determine the causal link between EN and IBD. Genetic variations associated with Crohn's disease (CD) and ulcerative colitis (UC) were derived from accessible genome-wide association studies pertaining to European ancestry. The FinnGen database was used to find the genetic variations containing EN. In the forward model, IBD was identified as the exposure, whereas in the reverse model, EN was identified as the exposure. The causal link between IBD and EN was examined using a range of different analysis techniques, the primary one being the inverse variance weighted (IVW) method, including inverse variance weighted-fixed effects (IVW-FE) and inverse-variance weighted-multiplicative random effects (IVW-MRE). To strengthen the results, assessments of sensitivity, heterogeneity, and pleiotropy were also conducted.

RESULTS

MR results showed that IBD increased the risk of EN (IVW-MRE: OR = 1.242, 95% CI = 1.068-1.443, p = 0.005). Furthermore, there was a strong correlation found between CD and a higher risk of EN (IVW-FE: OR = 1.250, 95% CI = 1.119-1.396, p = 8.036 × 10-5 ). However, UC did not appear to be linked to EN (IVW-FE: OR = 1.104, 95% CI = 0.868-1.405, p = 0.421). The reverse MR analysis findings did not imply that EN was linked to IBD. Horizontal pleiotropy did not appear to exist, and the robustness of these findings was confirmed.

CONCLUSION

The current investigation found that in European populations, IBD and its subtype CD could raise the incidence of EN.

Nakajo-Nishimura syndrome: an autoinflammatory disorder showing pernio-like rashes and progressive partial lipodystrophy

Nakajo-Nishimura syndrome (ORPHA2615; also registered as Nakajo syndrome in OMIM#256040) is a distinct inherited inflammatory and wasting disease, originally reported from Japan. This disease usually begins in early infancy with a pernio-like rash, especially in winter. The patients develop periodic high fever and nodular erythema-like eruptions, and gradually progress lipomuscular atrophy in the upper body, mainly the face and the upper extremities, to show the characteristic thin facial appearance and long clubbed fingers with joint contractures. So far about 30 cases have been reported from Kansai, especially Wakayama and Osaka, Tohoku and Kanto areas. At present, about 10 cases are confirmed to be alive only in the Kansai area, including one infant case in Wakayama. However, more cases are expected to be added in the near future. Although cause of the disease has long been undefined, a homozygous mutation of the PSMB8 gene, which encodes the β5i subunit of immunoproteasome, has been identified to be responsible in 2011. By analyses of the patients-derived cells and tissues, it has been suggested that accumulation of ubiquitinated and oxidated proteins due to immunoproteasome dysfunction causes hyperactivation of p38 mitogen-activated protein kinase and interleukin-6 overproduction. Since similar diseases with PSMB8 mutations have recently been reported from Europe and the United States, it is becoming clear that Nakajo-Nishimura syndrome and related disorders form proteasome disability syndromes, a new category of autoinflammatory diseases distributed globally.

Serum BAFF levels and skin mRNA expression in patients with Behçet's disease

OBJECTIVE

Serum levels of the B-cell activating factor in the tumor necrosis factor family (BAFF), a potent contributor to B-cell survival, are elevated in patients with systemic autoimmune diseases. The objective of this study was to determine serum BAFF levels and to link the results to the clinical features in patients with skin manifestations.

METHODS

Serum BAFF levels were examined by an enzyme-linked immunosorbent assay (ELISA) in 42 patients with BD (16 with active disease), 20 healthy controls, and in 20 patients with systemic lupus erythematosus (SLE) and 15 patients with multiple sclerosis (MS), who served as the disease control groups. Expression of BAFF messenger RNA (mRNA) in the skin was quantified by a real-time reverse transcription-polymerase chain reaction; the expression of BAFF receptor (BAFF-R) on CD19+ B cells was assessed by flow cytometry; and ELISA was used to evaluate the production of IgG, interleukin-6 (IL-6) and IL-10 by isolated B cells.

RESULTS

Serum BAFF levels were elevated in patients with active BD compared to the healthy controls, and correlated positively with the extent of skin lesions. Disease remission was accompanied by decreased BAFF levels. SLE patients had the highest serum BAFF levels. Skin biopsies showed BAFF mRNA expression to be up-regulated in active BD patients. BAFF-R expression on B cells was increased in BD patients with vasculitis. Furthermore, in BD patients the ability to produce IgG and IL-6 (but not IL-10) was enhanced in BAFF-stimulated B lymphocytes.

CONCLUSION

These results suggest that BAFF and its signalling in B cells contribute to B cell abnormalities and the development of skin disease in patients with BD.

Endothelial nitric oxide synthase polymorphisms in biopsy-proven erythema nodosum from a defined population

OBJECTIVE

To assess the potential in-fluence of endothelial nitric oxide synthase (eNOS) polymorphisms in the susceptibility to and clinical expression of a series of patients diagnosed with biopsy-proven erythema nodosum (EN).

METHODS

Ninety-seven unselected patients from Northwest Spain with biopsy-proven EN were studied. Patients and ethnically matched controls were genotyped by PCR based techniques for a variable number tandem repeat polymorphism in intron 4, a T/C polymorphism at position -786 in the promoter region and a polymorphism in exon 7 (298Glu/Asp or 5557G/T) of the eNOS gene.

RESULTS

No differences in allele or genotype frequencies for any of the individual eNOS polymorphisms were observed between biopsy-proven patients with EN and controls. It was also the case when patients with EN secondary to sarcoidosis were compared with the remaining patients or controls. In the group of patients with EN, no linkage disequilibrium between these polymorphisms was found. Also, no significant differences in haplotype frequencies were observed between patients and controls.

CONCLUSION

Our present results do not support a role for eNOS polymorphisms in the susceptibility to and clinical expression of EN.

Sex-specific manifestations of Löfgren's syndrome

MOTIVATION

It has been debated whether patients need to have erythema nodosum to be classified as having Löfgren's syndrome. In this study, we have therefore in detail evaluated and compared a large number of patients with an acute onset of sarcoidosis and bilateral hilar lymphadenopathy (BHL), with or without erythema nodosum (EN). This study is important because it may lead to a more accurate definition of Löfgren's syndrome, and an exact phenotype of patients is crucial in modern medical research.

BACKGROUND

Löfgren's syndrome is commonly regarded as a distinct clinical entity.

METHODS

We have in detail evaluated a large group of patients (n = 150) with an acute onset of sarcoidosis with BHL, in most cases with fever, EN, and/or bilateral ankle arthritis or periarticular inflammation. Within this group, 87 patients had EN (EN positive), whereas 63 were without EN (EN negative), though with distinct symmetric ankle inflammation.

RESULTS

EN-positive and EN-negative patients were identical in every aspect except that there were significantly more women in the EN-positive group: 58 women (67%) in the EN-positive group compared with only 17 (27%) women in the EN-negative group (p < 0.0001). In all other aspects, such as age, smoking habits, seasonal clustering of disease onset, rate of positive biopsies, chest radiography, pulmonary function, bronchoalveolar lavage cell distributions including the typically increased CD4/CD8 ratio, and clinical development of the disease, the EN-positive and EN-negative groups were close to identical. The two groups were also identically strongly associated with HLA-DRB1*0301/DQB1*0201, with 60 (69.0%) and 44 (69.8%) patients having this particular HLA type in the EN-positive and EN-negative groups, respectively. Such patients recovered to the same degree-that is, at almost 100%.

CONCLUSIONS

We conclude that manifestations of Löfgren's syndrome differ between men and women, with EN found predominantly in women, whereas a marked periarticular inflammation of the ankles or ankle arthritis without EN is seen preferentially in men.

CTLA-4 gene 49A/G polymorphism in Turkish patients with Behçet's disease

Genetic factors predisposing individuals to Behçet's disease (BD) are considered to play important roles in the development of the disease. Patients with BD exhibit elevated levels of pro-inflammatory cytokines, and affected organs show a significant neutrophil and lymphocyte infiltration. Current evidence suggests that the activated lymphocytes contribute to neutrophil and endothelial cell activation in these patients. The cytotoxic T lymphocyte-associated antigen (CTLA)-4 molecule plays an important role in immune regulation by downregulating T-cell activation, and the CTLA-4 49A/G polymorphism in the exon 1 has been shown to be associated with a number of autoimmune diseases. In an attempt to demonstrate whether there is an association of the CTLA-4 49A/G polymorphism with BD in the Turkish population, we genotyped 59 Turkish patients and 99 healthy individuals for single-nucleotide polymorphisms. For this purpose, genomic DNA was obtained from the peripheral blood of individuals and the region of interest was amplified using PCR. Genotyping was performed using the BbvI restriction endonuclease. It was shown that the distribution of the CTLA-4 exon 1 49A/G allele and genotype frequencies did not differ between patients with BD and healthy controls. However, allele and genotype frequencies of CTLA-4 49 A and A/A were significantly higher in patients with ocular involvement compared with patients without these symptoms (90.6% vs. 65.1%, odds ratio (OR) = 9.67, P = 0.011; and 81.25% vs. 39.5%, OR = 9.56, P = 0.015, respectively). A statistically significant difference in the A allele frequency was observed in patients with erythema nodosum-like lesions (86.1% vs. 65.8%, OR = 6.24, P = 0.04). There was also an increase in A/A genotype frequency, but the difference was not statistically significant (72.2% vs. 41.5%, OR = 6.5, P = 0.068). Our data suggest that BD patients with ocular involvement and erythema nodosum-like lesions have a higher frequency of both the A allele and the A/A genotype at position 49 of exon 1 of CTLA-4. These results may also indicate that CTLA-4 is a disease-modifying rather than a susceptibility gene for BD.

E-selectin polymorphism in erythema nodosum secondary to sarcoidosis

OBJECTIVE

E-selectin is expressed on cytokine-stimulated endothelial cells and plays an important role in leukocyte-endothelium interactions and inflammatory cell recruitment. An A/C polymorphism at position +561 in the E-selectin gene, which yields an amino acid exchange from serine to arginine at position 128 in the epidermal growth factor-like domain, has been described. We have assessed whether this bi-allelic polymorphism may be implicated in the clinical expression of erythema nodosum (EN) secondary to sarcoidosis.

METHODS

Thirty-one patients with biopsy-proven erythema nodosum (EN) associated with sarcoidosis, 68 patients with biopsy-proven EN related to other etiologies and 66 healthy matched controls from the Lugo region of Northwest Spain were studied. Patients and controls were genotyped for the A/C polymorphism gene by PCR-restriction fragment length polymorphism.

RESULTS

A significantly reduced frequency of the C mutant allele was observed in patients with EN secondary to sarcoidosis compared to controls (p = 0.019) and also compared to patients with EN unrelated to sarcoidosis (p = 0.028). This was also the case when the distribution of genotypes in patients with sarcoidosis was compared with that observed in patients with EN due to other etiologies (p = 0.028) and controls (p = 0.037). This was due to an absence in both C/A heterozygotes and C/C homozygotes in patients with EN secondary to sarcoidosis.

CONCLUSIONS

The present study constitutes the first attempt to assess the influence of E-selectin polymorphism at position +561 in the development of sarcoidosis. The C allele at the +561 position of the E-selectin gene is associated with significantly reduced risk of developing sarcoidosis in patients with EN.

C-C chemokine receptor 2 and sarcoidosis: association with Lofgren's syndrome

Sarcoidosis is thought to result from the interaction between an unknown environmental antigenic trigger and the host's genetic susceptibility. We hypothesized that sarcoidosis, or one of the disease subsets, could be associated with single nucleotide polymorphisms of C-C chemokine receptor 2 (CCR2) gene. Eight single-nucleotide polymorphisms in CCR2 were studied in a total of 304 Dutch individuals (90 non-Löfgren sarcoidosis, 47 Löfgren's syndrome, 167 control subjects). From the investigated CCR2 polymorphisms, nine haplotypes were deduced (haplotypes 1-9). In patients with Löfgren's syndrome, a strongly significant increase in the frequency of CCR2-haplotype 2, which includes four unique alleles (A at nucleotide position -6752, A at 3,000, T at 3,547, and T at 4,385), was observed compared with control subjects (74% vs. 38% respectively, p < 0.0001), whereas no difference was found between non-Löfgren sarcoidosis and control subjects (both 38%). The association between CCR2-haplotype 2 carriage frequency and Löfgren's syndrome (odds ratio, 4.4; p < 0.0001) remained significant after adjustment for human leukocyte antigen haplotype DRB1*0301-DQB1*0201 (odds ratio, 11.5; p < 0.0001) and female sex (odds ratio, 3.2; p = 0.003), two known risk factors for Löfgren's syndrome. In conclusion, this report describes a strong association between CCR2-haplotype 2 and Löfgren's syndrome. Further studies are needed to understand the molecular mechanisms underlying this association.

Uveitis and erythema nodosum in inflammatory bowel disease: clinical features and the role of HLA genes

BACKGROUND & AIMS

There are few systematic studies on the natural history or immunogenetic associations of erythema nodosum (EN) or ocular inflammation in inflammatory bowel disease (IBD), but they are reportedly more common in patients with other extraintestinal manifestations (EIMs), particularly arthritis. Immunogenetic associations have previously been described in IBD arthritis and in EN associated with sarcoidosis. This study examined the clinical features and HLA-B, DR, and tumor necrosis factor alpha (TNF-alpha) associations of ocular inflammation and EN and their clinical and immunogenetic relationship to arthritis in IBD.

METHODS

Details of EN and ocular inflammation were gathered by case-note review and questionnaire in 976 ulcerative colitis patients and 483 Crohn's patients. Sequence-specific PCR typing for polymorphisms in HLA-B, DR, and TNF-alpha was performed in 39 EN and 40 ocular patients. Results were compared with 490 IBD controls without EIMs, 38 patients with type 1 and 31 with type 2 peripheral arthritis, and 16 AS patients.

RESULTS

EN and ocular inflammation were more common in women, were associated with IBD relapse, and recurred in approximately 30% of patients. They occurred more commonly with arthritis and AS than expected by chance. Ocular inflammation was strongly associated with HLA-B*27, B*58, and HLA-DRB1*0103. There is a weak association between EN and HLA-B*15 but a strong association with the -1031 TNF-alpha.

CONCLUSIONS

EN, uveitis, and arthritis associated with IBD occur together commonly. They are associated with genes in the HLA region, and linkage disequilibrium between these genes may account for the clinical picture of overlapping but independent clinical manifestations.

Macrophage migration inhibitory factor gene polymorphism is associated with sarcoidosis in biopsy proven erythema nodosum

OBJECTIVE

To assess whether polymorphism of the macrophage migration inhibitory factor (MIF) gene at the position -173 is implicated in the development of sarcoidosis.

METHODS

Twenty-eight patients with biopsy proven erythema nodosum (EN) associated with sarcoidosis, 70 patients with biopsy proven EN related to other etiologies, and 122 healthy matched controls from the Lugo region of Northwest Spain were studied. Patients and controls were genotyped for a single nucleotide polymorphism in the 5'-flanking region at position -173 of the MIF gene, using SNapshot ddNTP primer extension, followed by capillary electrophoresis (ABI 3100).

RESULTS

A significantly increased frequency of the C mutant allele was observed in patients with EN secondary to sarcoidosis compared to controls (p = 0.0016; p(corr) = 0.0032; OR 2.78, 95% CI 1.45, 5.35) and also compared to patients with EN unrelated to sarcoidosis (p = 0.0004; p(corr) = 0.0008; OR 3.72, 95% CI 1.75, 7.87). Patients with EN carrying an MIF 173 C allele were found to have an increased risk of sarcoidosis (57% in EN secondary to sarcoidosis vs 24% in patients with EN related to other etiologies; p = 0.002; p(corr) = 0.004; OR 4.16, 95% CI 1.64, 10.50).

CONCLUSION

This is the first attempt to assess the influence of MIF genetic polymorphism at position -173 in the development of sarcoidosis. The MIF 173 C allele is associated with a significantly increased risk of developing sarcoidosis in patients with EN.

HLA-DRB1 associations in biopsy proven erythema nodosum

OBJECTIVE

To examine the HLA-DRB1 associations of patients with erythema nodosum (EN), establish HLA-DRB1 differences among patients with idiopathic and secondary EN, and identify the HLA-DRB1 associations with specific conditions presenting with EN.

METHODS

We conducted a retrospective study of 100 patients (83 women) with biopsy proven EN diagnosed for a defined population in Northwest Spain. Patients were classified into idiopathic or secondary if skin nodules occurred in the context of a well defined disease, or there was a precipitating event in close temporal relationship with the onset of EN. Patients and controls were HLA-DRB1 genotyped from DNA using molecular based methods.

RESULTS

At the time of diagnosis no precipitating events or underlying diseases were identified in 35 cases and, due to this, they were considered to be idiopathic. Although strong associations do not appear to exist between HLA-DRB1 and unstratified EN, the idiopathic group showed a significantly lower frequency of HLA-DRB1*04 phenotype compared with controls. Among the patients with secondary EN, the patient subgroup with sarcoidosis exhibited a significantly increased frequency of HLA-DRB1* 13 compared with healthy controls.

CONCLUSION

Idiopathic and some groups of secondary EN seem to have different HLA-DRB1 associations. These differences may have prognostic value in identifying patients with specific conditions associated with this syndrome.

HLA-B51 and its allelic types in association with Behçet's disease and recurrent aphthous stomatitis in Korea

OBJECTIVE

This case-control study was undertaken to evaluate the association of HLA-B51 antigen and its allelic types with Behçet's disease (BD) and with recurrent aphthous stomatitis (RAS), to investigate the degree of this association with diagnostic types and clinical variables of BD.

METHODS

The DNA typing of HLA-B51 by nested PCR-SSP was performed in 61 patients with BD, 56 patients with RAS, and in 70 healthy controls. Also, blind quality control study was done to assess the accuracy of nested PCR-SSP in HLA-B51-positive and negative BD patients on the microlymphocytotoxicity. In addition, direct DNA sequencing analysis was carried out in HLA-B51-positive individuals.

RESULTS

The outcome of nested PCR-SSP showed 100% concordance with those of the microlymphocytotoxicity. The prevalence of HLA-B51 in patients with BD was 55.7%, 16.1% in patients with RAS, and 15.7% in healthy controls. According to the diagnostic types of BD, all ten patients with complete BD had HLA-B51 antigen, and 47.1% in patients with incomplete BD (p = 0.002). In addition, the prevalence of HLA-B51 was statistically significant in patients with BD who had uveitis (p = 0.003) or erythema nodosum (p = 0.042). Direct DNA sequencing analysis revealed that the major allelic types in BD, RAS, and in healthy control were mostly HLA-B*51011.

CONCLUSIONS

Compared to patients with RAS or healthy controls, prevalence of HLA-B51 in the Korean patients with BD was much higher. The BD patients with B51 seemed to be susceptible for manifesting uveitis, erythema nodosum, and the full-blown syndrome as complete BD. Therefore the presence of HLA-B51 antigen in BD patients would be a genetic marker for the severe disease. In addition, there was no difference on the major allelic types of HLA-B51 in BD, RAS, and in healthy control.

Tumour necrosis factor-alpha promoter polymorphism in erythema nodosum

Erythema nodosum is a common skin disease characterized by erythematous, tender subcutaneous nodules, mostly located on the lower extremities. Little is known about its pathogenesis, although a wide variety of aetiological factors (e.g. bacterial and viral infections, neoplastic diseases and drugs) have been described. Sarcoidosis, a typical granulomatous disease, often occurs in association with erythema nodosum (Loefgren syndrome). Since granulomatous diseases have been closely linked to a deregulated tumour necrosis factor (TNF)-alpha production, it was tempting to speculate whether TNF-alpha might play a role in the pathogenesis of erythema nodosum, at least in cases associated with sarcoidosis. A previously described nucleotide exchange, (G-A) at position -308 in the human TNF-alpha gene promoter, has been shown to be a major cause for enhanced TNF-alpha production. In the present report, we investigated the genomic TNF-alpha promoter region in patients suffering from EN with and without underlying sarcoidosis. Our results showed a strong correlation between the uncommon TNF A II allele and sarcoidosis-associated erythema nodosum. Patients with erythema nodosum without underlying sarcoidosis displayed a similar allele frequency compared with controls. Taken together, we provide evidence that erythema nodosum in association with sarcoidosis might be pathogenically linked to altered TNF-alpha production due to a genetic promoter polymorphism.

Anti-inflammatory drugs block cytokine mRNA accumulation in the skin and improve the clinical condition of reactional leprosy patients

The aim of this study was to investigate in what ways in vivo anti-inflammatory treatment affects cytokine mRNA expression in situ in both erythema nodosum leprosum and reversal reaction patients. Serial biopsies were collected from the patients undergoing leprosy reactions before and during pentoxifylline (n = 7) or thalidomide (n = 3) treatment for erythema nodosum leprosum and prednisone (n = 3) for reversal reaction. Clinical evolution of the skin lesion was assessed during the study and semiquantitative reverse transcription-polymerase chain reaction was used to investigate cytokine mRNA expression at the lesion site. Results showed expression of interferon-gamma, interleukin-6, interleukin-10, interleukin-12 p40, and tumor necrosis factor-alpha in all patients tested at the onset of reactional episodes, but interleukin-4 mRNA was rarely detected in the lesions (n = 4). Follow-up analysis showed that, irrespective of the drugs used, tumor necrosis factor-alpha mRNA was diminished in 10 of the 13 patients tested. A concomitant decrease of mRNA accumulation was also observed for interferon-gamma (nine of 11 patients), interleukin-6 (nine of 11), and interleukin-12 p40 (six of eight). An inhibitory effect on interleukin-10 mRNA was likewise seen after thalidomide and pentoxifylline, but not subsequent to prednisone treatment. The data also demonstrated that cytokine mRNA inhibition correlates to the resolution of the inflammatory response in situ (n = 10), whereas the persistence/enhancement of cytokine message expression after treatment was associated with worsening of the skin condition, as seen in three erythema nodosum leprosum patients whose maintenance of local inflammation was accompanied by the appearance/persistence of interleukin-4 gene expression in situ subsequent to anti-inflammatory treatment. In summary, the participation of cytokines in leprosy inflammatory episodes seems to be directly associated with the patients' clinical evolution following therapy for reaction.

Elevated Th1 cytokine mRNA in skin biopsies and peripheral circulation in patients with erythema nodosum

It is generally believed that erythema nodosum is the result of an immunologic attack centered within the subcutaneous fat. This belief, however, is based on indirect evidence. The aim of this study was to analyze whether erythema nodosum could represent an example of a polarized Th1 or Th2 immune response. We have studied herein, by semiquantitative coupled reverse transcription-polymerase chain reaction the Th1 (IL-2, IFN-gamma) and Th2 (IL-4, IL-10) cytokine gene expression in skin biopsies and peripheral blood from eleven patients with erythema nodosum. As controls, we studied skin and peripheral blood from nine healthy subjects. We found expression of Th1 cytokines in most erythema nodosum skin lesions as well as in their peripheral blood. Both Th1 and Th2 cytokine gene expressions were scarcely or not detected in the skin and peripheral blood of control subjects. These results directly demonstrate that a polarized Th1 immune response occurs in the skin lesions of erythema nodosum patients regardless of the wide variety of provoking agents.

Association of C4B deficiency (C4B*Q0) with erythema nodosum in leprosy

A considerable number of studies have postulated significant associations between susceptibility to the different clinical manifestations of leprosy and the MHC. In this investigation, the association between the MHC class III complement proteins C2, BF, C4A and C4B and leprosy in a patient population of Southern Brazil was studied. A total of 109 non-related leprosy patients was investigated; 73 presented with lepromatous leprosy (LL), 46 of them had the immunopathological reaction of erythema nodosum (ENL), the remaining 36 were tuberculoid, borderline and indeterminate leprosy (TIBL) patients. The control group included 172 healthy individuals matched with the patients according to their ethnic and geographical origin. C2, BF, C4A and C4B allotypes were determined by standard technologies including Western blots for C2 and C4 variant alleles with monoclonal and polyclonal antibodies. Non-expressed ('silent') C4 alleles in hemizygously deficient individuals were estimated semiquantitatively on the basis of the C4A and C4B isotype ratio and by the MASC ('minimal chi-square') method. The results showed a significantly elevated presence of the non-expressed C4B allele (C4B*Q0) in the LL and ENL patient groups in comparison with the controls. The most significant difference was observed in the ENL group when compared with the controls. In addition, all patients who were homozygously C4B-deficient had ENL, and most of them had the BF*F1 allele. The comparison between LL patients with and without ENL also showed a statistically significant difference in the presence of C4B*Q0, indicating that C4B deficiency itself is associated with ENL. The relative risk of LL patients with the C4B*Q0 allele suffering from ENL was 5.3 compared with LL patients without C4B*Q0. Since immune complexes (IC) are considered to be the pathogenic cause of ENL, our findings indicate that C4B deficiency may play an important role in the abnormal immune response against Mycobacterium leprae and in the lack of IC clearance, leading to ENL reactions. Individuals with this allele seem to be at a higher risk of developing pathological immune reactivity in lepromatous leprosy.

Familial erythema nodosum

Erythema nodosum (EN) is a hypersensitivity reaction associated with many diseases. We describe a family in which 4 sisters had acute or recurrent EN. HLA typing showed a common haplotype in the affected members of the family. A review of familial EN and HLA distribution in EN is presented.

[Familial sarcoidosis]

Familial sarcoidosis is a pathologic association rarely described in the Spanish literature. We present a study of a family in which two members were clinically affected (Löfgren's syndrome) existing subclinical pathological signs in the rest. Based on this association the epidemiological, clinical and pathogenic mechanisms of familial sarcoidosis are reviewed with special attention to the incidence of this association in literature (in the Spanish literature in particular) and in the study of histocompatibility antigens in these patients. To conclude, the importance of investigating in a directed manner, the existence of familial sarcoidosis is emphasized since it offers an exceptional opportunity for the study of the pathogenic aspects (genetic and environmental) of this disease.

A syndrome with nodular erythema, elongated and thickened fingers, and emaciation

A 5-year-old boy had a nodular erythema, elongated and thickened fingers, and emaciation. His condition was a rare congenital disease inherited as an autosomal recessive trait. Eleven cases have been previously reported in the Japanese literature. The onset is early in childhood, and nodular erythema is an essential and initial finding. Growth retardation and emaciation progress slowly with age. The characteristic clinical features include large eyes, nose, lips, and ears, disproportionately long and thick fingers, and the loss of adipose tissue from the upper half of the body. Cardiomegaly and hypertrophy of the periosteum of the phalanges have been described in some cases.

Erythema nodosum: occurrence in two siblings and mother

Erythema nodosum is an allergic response clinically associated with certain disease states, tuberculosis and streptococcal infec tions being most often incriminated. One family, including two siblings and their mother, developed erythema nodosum within one week of each other. The importance of primary tuberculosis as the etiology in the two sibs and the possibility of a double eti ology in one are stressed. This author also reviews this fascinating problem for us.