Objectives: Idiopathic inflammatory myopathies (IIM) are a group of muscle diseases characterized by inflammatory infiltrates in skeletal muscle. Associated pathways include increased antigen presentation with tissue specific inflammatory signatures could be related to the proteasome system. In this study we investigated the contribution of the proteasome in IIM.

Methods: Real time PCR was used for relative quantification of mRNA transcripts of proteasomal beta subunits in muscle biopsies from 21 patients with IIM in comparison to 13 patients with non-inflammatory myopathies (NI). Expression levels of the constitutive beta subunits (PSMB5, -6, -7), and the corresponding immunosubunits (PSMB8, -9, -10) were measured relative to different housekeeping genes (HKG). GeNorm, NormFinder and BestKeeper were used to evaluate the expression stability of HPRT1, ACTB and GAPDH as HKG.

Results: HPRT1 was identified as the most stable reference gene in the investigated biopsies. The analysis demonstrated that irrespective of the clinical disease classification, transcripts of PSMB8 and PSMB9 were upregulated in biopsies of all types of IIM and correlated with the intensity of inflammation. Furthermore, expression ratios of PSMB5:PSMB8 and PSMB6:PSMB9 differentiated clearly between IIM and NI.

Conclusions: The quantification of PSMB8 and PSMB9 could qualify for diagnostic scoring of inflammation in myopathy muscles.

Background: Henoch schonlein purpura (HSP) is one of the most common vasculitides of unknown etiology in childhood. It is a non-Granulomatous vasculitis that is characterized by deposition of immunoglobulin A, complement and immune complex in blood vessel wall as well as renal mesangium. Aim of the study: To describe the demographic, epidemiologic, clinical characteristics and possible etiology of HSP patients. Design: Retrospective descriptive observational study.

Patients and Methods: Medical records of all patients who diagnosed as HSP according to the European league against rheumatism and pediatric rheumatology European society (EULAR\ PReS) criteria and followed up at Tripoli Children Hospital rheumatology and nephrology departments from January 2005 to June 2017 were reviewed.

Results: 75 Children were included in the study, of these 40 were boys giving a male to female ratio of 1.14: 1. Their ages ranged from 2 to 12 years (mean age 6.5 ± 1.5 years). At the time of diagnosis, 50.7% of patients were ≤ 5 years and 93.4% were less than 10 years, with peak age onset of 2-9 years. Upper respiratory tract infection (URTI) preceded the onset of the disease in 57.3% of the patients. 100% of the patients had rash either at presentation or during the disease course. Joint involvement observed in 80%, with the ankles the most frequently affected joints. Gastrointestinal (GIT) involvement occurred in 65% of patients, the dominant digestive clinical features were abdominal pain and vomiting. Renal involvement documented in 40% with various degrees of severity, none of our patients had acute renal failure.73.3% of patients treated as in-patient and steroid was used in 53.3% with a mean duration of 10 days. None of our patients developed chronic renal failure or hypertension as long-term sequels.

Conclusion: HSP is a mild disease, etiology, epidemiological, clinical findings and etiological factors of HSP patients in our region were found to be similar to those reported in the national and international studies, more research is warranted to study the prevalence and complications of HSP in Libyan based cohort.