Recurrent pneumococcal arthritis as the presenting manifestation of X-linked agammaglobulinemia

The genetic basis of pneumococcal and staphylococcal infections: inborn errors of human TLR and IL-1R immunity

Many bacteria can cause pyogenic lesions in humans. Most of these bacteria are harmless in most individuals, but they, nevertheless, cause significant morbidity and mortality worldwide. The inherited and acquired immunodeficiencies underlying these pyogenic infections differ between bacteria. This short review focuses on two emblematic pyogenic bacteria: pneumococcus (Streptococcus pneumoniae) and Staphylococcus, both of which are Gram-positive encapsulated bacteria. We will discuss the contribution of human genetic studies to the identification of germline mutations of the TLR and IL-1R pathways.

Osteoarticular infectious complications in patients with primary immunodeficiencies

PURPOSE OF REVIEW

To describe the incidence and management of various infectious arthritides in selected primary immunodeficiency states.

RECENT FINDINGS

Joint complications have been a well recognized finding in patients with primary immunodeficiencies for many years. Many are clearly infectious in etiology, but other apparently noninfectious joint abnormalities similar to rheumatoid arthritis have been shown to be due to an underlying infectious trigger. In humoral immunodeficiencies such as common variable immunodeficiency and X-linked agammaglobulinemia, bacterial organisms are the most common causes of infectious arthritis, but mycoplasmas and ureaplasmas are also of particular importance. In nonhumoral immunodeficiencies, noninfectious inflammatory arthritides are more prevalent, although microbiologic organisms have been reported in some cases of arthritis. Lack of appropriate culturing techniques and documentation of infectious agents may underestimate the prevalence of low-virulence infections in these patients.

SUMMARY

Infectious arthritis is a significant comorbidity associated with primary immunodeficiencies and can be the presenting feature for some patients. Prompt examination for common as well as atypical organisms is not only important for the treatment but also crucial to the understanding of the exact etiology of arthritides as a whole in these disorders.

Arthrite à pneumocoque révélant un myélome

INTRODUCTION

The most common presenting features of multiple myeloma are bone pain, anemia, renal failure or hypercalcemia. Bacterial infection as the initial presentation of this desease is rare.

CLINICAL CASE

We report the case of a 62-year-old man with pneumococcal septic arthritis of the knee revealing a multiple myeloma.

DISCUSSION

Pneumococcal infection should lead to a suspicion of underlying illness and especially the multiple myeloma.

IRAK4 and NEMO mutations in otherwise healthy children with recurrent invasive pneumococcal disease

BACKGROUND

About 2% of childhood episodes of invasive pneumococcal disease (IPD) are recurrent, and most remain unexplained.

OBJECTIVE

To report two cases of otherwise healthy, unrelated children with recurrent IPD as the only clinical infectious manifestation of an inherited disorder in nuclear factor-kappaB(NF-kappaB)-dependent immunity.

RESULTS

One child carried two germline mutations in IRAK4, and had impaired cellular responses to interleukin (IL)1 receptor and toll-like receptor (TLR) stimulation. The other child carried a hemizygous mutation in NEMO, associated with a broader impairment of NF-kappaB activation, with an impaired cellular response to IL-1R, TLR and tumour necrosis factor receptor stimulation. The two patients shared a narrow clinical phenotype, associated with two related but different genotypes.

CONCLUSIONS

Otherwise healthy children with recurrent IPD should be explored for underlying primary immunodeficiencies affecting the IRAK4-dependent and NEMO-dependent signalling pathways.

Nationwide study of recurrent invasive pneumococcal infections in a population with a low prevalence of human immunodeficiency virus infection

Recurrent invasive infections caused by Streptococcus pneumoniae are rare, and often considered to be indicative of serious underlying illness. However, the prevalence of this problem, and the relevance of specific predisposing conditions, can be hard to assess, since many of the studies are based on specific risk groups. A population-based study of recurrent invasive pneumococcal disease in Iceland during the 30-year period 1975-2004 was performed. Clinical information, including mortality and vaccine use, was analysed retrospectively. Invasive pneumococcal isolates were serotyped and susceptibility testing was performed. During this period, 36 (4.4%) of 819 patients who survived an initial infection experienced recurrence, with a median time between episodes of 9.7 months. Pneumonia with bacteraemia was the most common clinical diagnosis (48% of cases), followed by bacteraemia without a clear focus (21%) and meningitis (13%). Most (94%) of the patients had identifiable predisposing conditions, most commonly, multiple myeloma in adults, and antibody deficiencies in children. Compared with children, adults were more likely to present with pneumonia (65% vs. 18%; p 0.0001). No significant change in the 30-day mortality rate was observed during the three decades of the study. Only 26% of eligible patients received pneumococcal vaccination. Patients with recurrent invasive pneumococcal disease should be investigated thoroughly for underlying diseases. Greater use of pneumococcal vaccines should be encouraged among high-risk patients. More effective preventive and therapeutic measures are needed to improve outcomes.

Pneumococcal septic arthritis: review of 190 cases

This article reports 13 cases of pneumococcal septic arthritis and reviews another 177 cases reported since 1965. Of 2407 cases of septic arthritis from large series, 156 (6%) were caused by Streptococcus pneumoniae. Mortality was 19% among adults and 0% among children. Pneumococcal bacteremia was the strongest predictor of mortality. At least 1 knee was involved in 56% of adults. Polyarticular disease (36%) and bacteremia (72%) were more common among adults with septic arthritis caused by S. pneumoniae than among adults with other causative organisms. Only 50% of adults with pneumococcal septic arthritis had another focus of pneumococcal infection, such as pneumonia. Functional outcomes were good in 95% of patients. Uncomplicated pneumococcal septic arthritis can be managed with arthrocentesis and 4 weeks of antibiotic therapy; most cases of pneumococcal prosthetic joint infection can be managed without prosthesis removal. A fatal case of septic arthritis caused by a beta-lactam-resistant strain of S. pneumoniae is also presented.