Cas9-Mediated Nanopore Sequencing Enables Precise Characterization of Structural Variants in CCM Genes

Deletions in the CCM1, CCM2, and CCM3 genes are a common cause of familial cerebral cavernous malformations (CCMs). In current molecular genetic laboratories, targeted next-generation sequencing or multiplex ligation-dependent probe amplification are mostly used to identify copy number variants (CNVs). However, both techniques are limited in their ability to specify the breakpoints of CNVs and identify complex structural variants (SVs). To overcome these constraints, we established a targeted Cas9-mediated nanopore sequencing approach for CNV detection with single nucleotide resolution. Using a MinION device, we achieved complete coverage for the CCM genes and determined the exact size of CNVs in positive controls. Long-read sequencing for a CCM1 and CCM2 CNV revealed that the adjacent ANKIB1 and NACAD genes were also partially or completely deleted. In addition, an interchromosomal insertion and an inversion in CCM2 were reliably re-identified by long-read sequencing. The refinement of CNV breakpoints by long-read sequencing enabled fast and inexpensive PCR-based variant confirmation, which is highly desirable to reduce costs in subsequent family analyses. In conclusion, Cas9-mediated nanopore sequencing is a cost-effective and flexible tool for molecular genetic diagnostics which can be easily adapted to various target regions.

[Epidural lipomatosis]

ONSET: Epidural lipomatosis is a rare disorder defined as a pathological overgrowth of normal epidural fat. It is more often associated with administration of exogenous steroid with variable duration and doses. Furthermore, it may occur in some patients in the absence of exposure to steroids but generally associated with obesity. Whatever the predisposing factor, the majority of these patients are men. The causal effect of epidural lipomatosis in the development of spinal cord or radicular compression is generally well accepted.

DIAGNOSIS

The diagnosis of epidural lipomatosis can be established by melography, computed tomography (CT) and magnetic resonance imaging (MRI). MRI is considered the imaging procedure of choice, allowing an assessment of the extent of lipomatosis and, as well as CT, an identification of the lipomatous tissue. Most cases of epidural lipomatosis with corticosteroid use occur in the thoracic region, while most idiopathic cases occur in the lumbar region.

TREATMENT

Management of treatment depends on the severity of the neurological signs and the patient's background. The most common treatment for epidural lipomatosis with corticosteroid use consists in surgical decompression but with a high risk of postoperative mortality. In some cases however, medical treatment includes corticosteroid withdrawal or reduction and calorie restriction, leading to clinical improvement. Treatment for idiopathic epidural lipomatosis is more often medical, based on weight loss and physical therapy with generally successful outcome. The pathogenesis of epidural lipomatosis remains unknown but different suggested hypotheses may lead to a metabolic disorder as the underlying cause.

[Acute pancreatitis in rheumatoid purpura. Apropos of 2 cases]

Abdominal pain observed in Henoch-Schönlein purpura (HSP) is usually attributed to digestive tract involvement. Pancreatic involvement is a rare and benign complication. The authors report two cases of acute pancreatitis as a complication of HSP. Pancreatitis was confirmed in both cases by clinical presentation and increase of serum amylase levels. Abdominal echography has demonstrated ascites or alithiasic cholecystitis without pancreatic abnormality. The prognosis was favourable in each case. Pathophysiologic mechanism is presumably a vasculitis of the small vessels specially within the pancreas leading to inflammation. Abdominal pain can be explained by a digestive tract involvement but also by an acute pancreatitis. This later occurrence is not as exceptional as reported in the literature. Thus, serum amylase levels should be evaluated in patients with HSP who have intense epigastric or abdominal pain, in order to recognize a pancreatic involvement.

Chronic hepatitis during rheumatoid arthritis

Chronic hepatitis is infrequently reported in the course of RA (1.9%). We report 6 cases with such an association. The six patients were all female (mean age: 59.5 years) with typical RA (ACR criteria), and sicca syndrome in 5 cases. Chronic hepatitis always developed after the onset of RA (delay: 1 to 47 years). Laboratory findings revealed a mild increase of transaminases. Alkaline phosphatase were increased in 3 cases. Liver insufficiency was present in 4 cases and polyclonal hypergammaglobulinemia in 6 cases. Rheumatoid factors were detected in 5 cases; antinuclear antibodies and anti-smooth muscle antibodies were also detected in 5 cases. Histological examination of liver biopsy disclosed active chronic hepatitis in 5 cases (with cirrhosis in 3 cases) and persistent chronic hepatitis in 1 case. Steroid therapy was administered in 4 cases of active chronic hepatitis with clinical and biological improvement (18 months to 6 years follow-up). One patient died of gastric bleeding.

[Efficacy, tolerability and therapeutic benefit of etodolac (Lodine 200) in rheumatologic practice]

Efficacy, safety and therapeutic benefit of etodolac (Lodine 200) in rheumatological practice. An open clinical trial performed by 974 rheumatologists enabled an evaluation of efficacy, safety and therapeutic benefit of etodolac (Lodine 200) on 4,947 patients with rheumatoid arthritis, ankylosing spondylitis and osteoarthritis of the lower limbs; the initial dosage was 600 mg/d (for 2 weeks), then 400 to 600 mg/d (for 2 to 4 weeks, according to the indication). Efficacy, assessed by classical items for NSAID's, was shown to be excellent to good by 61-77 p. 100 of patients, according to the indication. 7.7 p. 100 of patients only dropped out for lack of efficacy. 20.4 p. 100 of patients developed adverse effect(s) (AE), but the relationship between etodolac and AE was assessed "possible" or "probable" only for 9.6 p. 100 of patients; this figure should be compared to the 7.6 p. 100 of patients who dropped out for AE and to the 92 p. 100 of patients who assessed the global safety as "excellent or good". The therapeutic benefit was estimated very favorable: 75 p. 100 of patients felt better than at the beginning of the study, 64.5 p. 100 of patients wished to continue the treatment and the (mean) benefit-risk ratio assessed with a logarithm scale (-1 to +1), ranged from 0.45 to 0.6 according to the indication. Therefore, this trial confirmed the good efficacy and safety profile of etodolac on a large scale in normal clinical practice in France, following assessments during controlled trials. It also permitted to perfect new items of evaluation for NSAID's, in particular for therapeutic benefit.

Spinal cord compression related to vertebral osteonecrosis

The authors report 3 cases of spinal cord compression by vertebral collapse related to osteonecrosis. Two patients needed surgical decompression permitting pathological diagnosis. In the third case, osteonecrosis was ascertained by radiological evidence of an intravertebral vacuum phenomenon. Three etiologic factors were noticed: osteoporosis, corticotherapy, and radiotherapy. The relative frequency of neurologic complications in vertebral collapse related to osteonecrosis compared to those observed in osteoporosis is discussed.

[Mechanism of Felty's syndrome and long-term course]

The authors report 18 cases of Felty's syndrome followed, in an average, for 5 years (1 to 12 years). There were 3 deaths, 9 patients are in complete remission, 6 others still show signs of the disease: splenomegaly (4 cases), leucopenia (1 case) and only one complete Felty's syndrome. Steroid therapy has proved to be effective regardless of the mechanism of the neutropenia specified in 9 cases by an isotopic study. Prognosis and infectious risk are difficult to determine but the overall course was rather favorable.

[Juvenile-onset ankylosing spondylitis]

Ankylosing spondylitis (AS) with juvenile onset (under 17 years of age) is not infrequent. Thirty-six cases were studied, amounting to 18% of patients hospitalized between 1977 and 1981. The following criteria were used for diagnosis: radiologic sacroiliitis (typical AS), presence of HLA B27 and/or pelvic or vertebral clinical manifestations (possible AS). 31 patients (85%) were boys. Mean age at onset was 12.3 +/- 2.8 years. In three cases, AS was found in a member of the family of the propositus and in one case there was cutaneous psoriasis. Usually (29 cases) onset was in the lower limbs: arthritis of the knee (14 cases), hip (9 cases), ankle (7 cases) or painful heel (4 cases). During the course (with a mean follow-up of 11.2 +/- 7 years), 35 patients exhibited peripheral joint diseases and 25 had axial involvement. Ocular involvement was present in 5 cases. 10 patients had a modification of respiratory function. Radiologic sacroiliitis was found in 31 patients but with a delay of 5.3 +/- 2.6 years. Vertebral radiologic lesions were only seen in 11 patients. Radiologic hip involvement was frequent (20 cases) with complete destruction in 6 patients. Erosion and ossification of the calcaneum were observed in 15 cases. The ESR was above 20 mm/first hour in 26 cases (72%). 81% of these patients were HLA B27 positive. Functional prognosis was good: 16 patients (51.6%) led an almost normal life, 6 were bedridden (Steinbrocker's grade IV), 3 had severe impairment (grade III) and 6 had slight impairment (grade II).(ABSTRACT TRUNCATED AT 250 WORDS)

[Destructive cervical spondylitis. An unusual initial manifestation of ankylosing spondylitis]

Erosions of vertebral bodies and intervertebral discs are usually considered as late manifestations of ankylosing spondylitis. Yet they may occur early and indeed constitute the first sign of the disease. This is illustrated by the case reported here, where a 19-year-old woman with an 18-months diagnosis of ankylosing spondylitis was found to have severe destructive lesions of the 6th cervical vertebra without discal lesion nor cervical ankylosis. Surgical biopsy excluded a tumoral or infectious process. Spinal fusion (C4-C7) was performed, and cervical pain was completely relieved with non-steroidal anti-inflammatory drugs.

[Treatment of lumbar disk hernias using chemonucleolysis]

The authors present 46 cases studies of herniated lumbar discs treated by chemonucleolysis in the previous 2 to 9 months. One patient suffered from recurrent acute lumbago; the other 45 patients suffered from lumbar root pain. The diagnosis of herniated disc was confirmed by radiography of the lumbar roots. Chemonucleolysis was performed under neuroleptanalgesia in the majority of cases, after failure of medical treatment and as an alternative to surgery. The patient treated for recurrent lumbago obtained a good result. After one month, 20 patients no longer suffered from sciatica and two had only a mild and intermittent sciatic pain. The results are lasting. Overall, chemonucleolysis is successful in 69% of cases. The success rate decreases with the age of the patient and the age of the symptoms. The results appear to be unchanged by the number of discs treated, their level or their discographic features. The results appear to be unchanged by the number of discs treated, their level or their discographic features. The results seem to be better when the disc being treated has not collapsed and when the hernia is not too large. Seven failed cases went to operation when, in each case, a non ruptured herniated disc was found. In 4 cases there was minimal tissue and in 2 cases the hernia was soft. The tolerance was excellent. Chemonucleolysis is effective in the treatment of herniated lumbar discs, but should be reserved for selected patients. Used with care, the treatment is safe. In cases where the treatment fails, the surgical procedure is not interefered with.

[Spinal osteonecrosis in adults. Apropos of 4 cases]

The authors report on 4 cases of aseptic osteonecrosis of the vertebral matter in adult. The relatively rare localisation is the lot of elderly patients. It may follow cobalt therapy or corticotherapy and seems to be brought about by osteoporosis, hypertriglyceridemia and, perhaps, malignant lymphoidal proliferation. Histological confirmation of osteonecrosis was available in one case. The radiological aspect is characterised by settling, with heterogenic osteo-condensation and gaseous dissection of the vertebral matter. A double vertebral localisation is possible, and scintigraphical hyperfixation is common. The course is slowly favourable, with a symptomatic treatment.

[Infectious sacroiliitis. Multicenter study of 214 cases]

Out of 214 cases of infective sacro-ileitis observed on Rheumatology Units, 65% were due to common bacteria, 25% were tuberculous and 10% due to brucellosis. Post-partum infections were early, severe and often due to streptococci. Sacrocoxalgia was accompanied in 50% of cases by another focus of active tuberculosis. Two clinical presentations are possible, either that of acute sacro-ileitis with a sudden onset, severe pain, frank infection and major impotence which is common in infections due to current bacteria; or the presentation may be that of subacute sacro-ileitis with progressive onset with little or no fever, pain and moderate impotence which may be due to any bacteria. Identification of the responsible organism depends on blood culture, bacterial sampling at the point of entry of the infection but, above all, direct swab or preferably needle biopsy. Bone scan may demonstrate early hyperfixation in the absence of any radiological signs. Prolonged antibiotic treatment is sufficient in most cases.

[Rheumatic manifestations of erythema elevatum diutinum]

The authors report on a case of erythema elevatum diutinum developing at the same time as a seropositive rheumatoid polyarthritis. Disulone, moderately active on skin lesions, has little influence on the development of arthritis that have reacted well to treatment with D-penicillamine. A review of the literature makes it possible to identify the type of rheumatismal manifestations and immunological disorders accompanying the dermatosis. Three etiological circumstances must be looked for : focal infection, malignant lymphopathy, connectivitis.

[Humeral lytic lesions and circulating anticoagulant in secondary syphilis (author's transl)]

A case of secondary syphilis revealed by rheumatic complaints is described. Arthralgia and myalgia were associated with lytic lesions and periostitis of both humerus. A more diffuse skeletal involvement was detected by bone scanning. A genital ulceration 4 months before, diffuse lymphadenopathy and a strongly positive serological reaction ascertain the diagnosis. The association of a circulating anticoagulant is discussed. All manifestations cleared with penicilline treatment.

Age-related changes in antibody-dependent cell-mediated cytotoxicity in mouse spleen

The age-related variation in antibody-dependent cell-mediated cytotoxicity (ADCC) in spleen was examined in four different mouse strains (DBA/2, Balb/c, NZB and NZB/NZW). The ADCC effector activity against antibody-coated chicken red blood cells in untreated spleen from all four strains was roughly comparable. An initial rise in activity with increasing age until two to three months was followed by a sharp decline in effector activity. Treatment of the spleen cells with poly-l-lysine-coated carbonyl iron to remove phagocytes resulted in a decrease in ADCC activity in NZB, NZB/NZW and DBA/2 strains at all ages examined. The same general pattern of age-dependent decline was still seen in these depleted spleens. However, the same treatment essentially abolished ADCC in Balb/c spleen at all ages studied.

Antibody-dependent cell-mediated cytotoxicity in selected autoimmune diseases

Antibody-dependent cell-mediated cytotoxicity mediated by peripheral blood lymphocytes was studied in patients with systemic lupus erythematosus, polyarteritis nodosa. Sjogren's syndrome, and rheumatoid arthritis. The target cells were chicken erythrocytes coated with rabbit anti-chicken erythrocyte antibody. Antibody-dependent cell-mediated cytotoxic activity was normal in Sjogren's syndrome and rheumatoid arthritis but significantly decreased (P is less than 0.001) in active systemic lupus erythematosus and in two patients with polyarteritis nodosa. A partial regeneration of antibody-dependent cell-mediated cytotoxic activity was obtained by treatment with pronase and DNase followed by overnight incubation. Sera from patients with systemic lupus erythematosus inhibited antibody-dependent cell-mediated cytotoxic activity of normal lymphocytes. The inhibitory activity was studied by specific immunoadsorption and sucrose density geadient ultracentrifugation. Removal of IgG but not IgM greatly reduced inhibition. Inhibitory factors were present in 7S and heavier fractions containing IgG. Five systemic lupus erythematosus patients were studied serially to determine if improvement in clinical status could be correlated with a decrease in serum inhibitory factors as studied by inhibition of normal antibody-dependent cell-mediated cytotoxicity. Indeed, a greater serum inhibitory capacity was found in each patient during periods of greater disease activity.

[HL-A antigens in patients with psoriatic rheumatism]

The authors studied HLA tissue groups for 28 specificities in 70 patients with psoriatic arthropathy (44 with pure peripheral arthropathy and 26 with axial involvement, 19 of whom also had peripheral lesions). Four antigens of this system were found with a significantly increased frequency in 70 patients in comparison with a control group of 152 normal subjects. For antigen HLA-B27, the frequency seemed very significantly increased in patients with axial involvement as compared with those without axial troubles (pc less than or equal to 0.0001) and with the controls (pc less than or equal to 0.0001). For antigen HLA-B13, the frequency was significantly increased in patients with axial involvement as compared with the controls (pc less than 0.05). Antigen HLA-Bw17 was present with significantly increased frequency as compared with the controls in the patients with peripheral involvement (pc less than 0.001). For antigen HLA-Bw38 (W16.1), the frequency in patients with or without axial involvement was significantly increased in comparison with the controls (pc less than 0.001). The interpretation of these results is discussed and the association of antigen HLA-B27 with sacro-iliac involvement once again stressed.

[W27 HL-A antigen. Diagnostic value in rheumatology]

The authors studied the tissue groups in a first series of patients with properly diagnosed rheumatic disorders. They found HL-A W27 antigen in 84 percent of 50 cases of primitive ankylosing spondylarthritis in adults, in 33 percent of the 50 cases of Fiessinger-Leroy-Reiter syndrome, in 20 percent of the 40 cases of psoriatic polyarthritis (50 percent of the 12 cases with radiological sacroiliac involvement) and in 66 percent of the 6 cases of spondylarthritis associated with haemorrhagic rectocolitis. In a second series of 45 patients with unclassifiable inflammatory rheumatism, only the W27 antigen tested for and it was found in 33 percent of the patients. On the basis of these observations, which were compared with those in other publications, the authors confirm the absence of a clear correlation between the pathological picture and the presence of the W27 antigen. They discuss the significance of the association between the W27 antigen and the disease, and underline the diagnostic and sometimes the prognostic value of the W27 test in rheumatology.