Septic arthritis and other infections of rheumatologic significance

Bacterial arthritis has been reported rarely in patients with human immunodeficiency virus infection and generally is associated with other risk factors such as intravenous drug use. Septic arthritis may be caused by opportunistic organisms and may be more common in hemophiliacs when associated with human immunodeficiency virus infection. Pyomyositis and osteomyelitis have also been reported more commonly.

Infectious agents, immunity, and rheumatic diseases

It should again be cautioned that these hypotheses are just that--hypotheses, for which there are some suggestive but not conclusive data. I have described these hypotheses using B27 and AS, and DR4 and RA. We are all aware that AS occurs in individuals who are B27 negative, and RA occurs in individuals who lack DR4. Although space does not permit further elaboration here, these hypotheses can be modified to take these additional associations into account. It should also be noted that even if the mechanisms advanced in these hypotheses prove to be true, different mechanisms may apply to different diseases, and several of these mechanisms may act in concert to produce disease. Nevertheless, these hypotheses provide a framework against which future experiments can be designed to further elucidate the relationship among infectious agents, immunity, and rheumatic diseases.

Rheumatological lesions in individuals with human immunodeficiency virus infection

One hundred and twenty-three patients with human immunodeficiency virus infection have been referred to rheumatologists at our hospitals between October 1985 and April 1989 because of musculoskeletal symptoms. Thirty-four homosexual men presented with acute, peripheral, non-erosive arthritis (mean number of four joints affected) with the knees being involved in 23. Other features developing concurrently with arthritis included psoriasis, keratoderma blenorrhagica, plantar fasciitis, urethritis, conjunctivitis and anterior uveitis. Four of five patients investigated were HLA-B27-positive; none of 15 patients tested had raised titres of rheumatoid or antinuclear factors. Various infections were associated with the onset of arthritis and two patients with a recent history of diarrhoea had serological evidence of yersinia infection. No micro-organisms were identified within the joint except for HIV itself. At the time of onset of arthritis four of these individuals had the acquired immunodeficiency syndrome (AIDS); 11 were not known to be HIV-positive before testing which was performed following referral for arthritis. Six patients have since developed AIDS and four have died. In 15 individuals, including those who progressed to AIDS, joint symptoms have been severe, persistent and poorly responsive to non-steroidal anti-inflammatory drugs. In only five patients has the arthritis been known to resolve. Synovitis has also been seen in two women: in one of these HIV infection was thought to have been acquired through intravenous drug abuse. Other rheumatic lesions included myalgia/myositis, non-inflammatory peripheral arthritis, spinal pain, soft tissue lesions, arthralgia or myalgia of unknown cause and infective lesions including septic arthritis and bony infection due to histoplasmosis and atypical mycobacterial infection. It appears likely that HIV infection is a risk factor for the development of seronegative arthritis and other rheumatic lesions.

Herpes simplex virus and the rheumatic diseases

A viral aetiology for rheumatoid arthritis and inflammatory connective tissue diseases has been sought in general terms first, by studying viral growth patterns in lymphocytes from the blood and lesions of patients affected second, by analysing lymphocyte concentrations of the interferon-induced enzyme 2-5 oligo-adenylate synthetase (2-5 A); and third, by probing Southern blots of lymphocyte DNA with viral probes. Indirect evidence consistent with a viral aetiology has been found in several such diseases, but direct proof has been difficult to adduce. There is some suggestion that herpes simplex viral (HSV) DNA is present in Behcet's blood lymphocytes, but the findings are inconsistent. It is also plausible that viruses such as HSV do not induce these diseases through classic immunopathological mechanisms, but as "promoters" of abnormal lymphoproliferation in individuals with predisposing defects, possibly related to selective DNA repair defects.

The rheumatic manifestations of infection with the human immunodeficiency virus

The recognized clinical spectrum of disease associated with HIV infection is rapidly expanding and now includes a variety of rheumatic syndromes. The laboratory features of HIV infection closely resemble those found in many connective tissue diseases and thus alter the predictive value of these tests in the evaluation of both types of conditions. In addition to the laboratory similarities, there are also increasing numbers of clinical reports of HIV-infected individuals who develop syndromes either resembling classic idiopathic rheumatic diseases such as SS, polymyositis, or SLE, or newly recognized illnesses that fall under the clinical domain of the rheumatologist (ie, HIV-associated vasculitis and arthritis). It is vital that clinicians recognize these new illnesses because there are important differences in prognosis and management between these and their idiopathic counterparts. Research is urgently needed for better definition of these syndromes and their pathogenesis, natural history, and optimal therapies.

[Antibiotic resistance of revertant cultures of Streptococcus group A and of unclassified streptococci isolated from the blood of rheumatism patients]

Sensitivity of one strain of group A Streptococcus, its L-form and revertant was tested to 7 antibiotics and it was observed that the revertant was highly resistant to beta-lactam antibiotics and lincomycin, tolerant to ristomycin and had a high value of MBcC/MIC for erythromycin and tetracycline. Testing of other analogous revertant strains showed the same results. In streptococcal strains freshly isolated from blood of patients with rheumatism and resistant to some antibiotics there were recorded by electron microscopy heterogeneity of their population and presence in it of a significant number of cells with altered (unevenly thickened) cell walls and cells with microcapsules on the cell wall surface characteristic of the revertants. In vivo occurrence of streptococcal revertants may be the cause of their antibiotic resistance which obviously requires correction of the rational antibiotic therapy schemes.

Chlamydial infection in a family

In a family comprising parents and two daughters, Chlamydia trachomatis (CT) was observed to be the infective agent causing urethritis in the father and conjunctivitis in the newborn. CT was probably a trigger factor in Reiter's syndrome (RS) in the mother, who suffered from arthritis, microscopic pyuria and hematuria, cervicitis and ocular manifestations. The elder daughter's mucocutaneous manifestations, probably keratodermia blennorrhagica, broke out simultaneously with chlamydial infections in the other members of the family. Later she developed joint pains, conjunctivitis and vulvitis. The elder daughter and the father are HLA-B27 negative, whereas the mother is HLA-B27 positive. With this study we would like to emphasize the importance of observing the microbial environment in the family in the etiology of rheumatic disease. Simultaneous treatment of infections in family members might benefit the clinical course of rheumatic disease.

Yersinia enterocolitica infections and rheumatic diseases

Yersinia enterocolitica (Y. ent.) infections are rather frequently complicated by acute reactive inflammation in the connective tissue, especially in the joints. At this stage of the disease the specific diagnosis can be obtained either by bacterial isolation and identification from the feces and/or mesenterial lymph nodes, or by serological methods. Serodiagnostics are frequently the only method during the complication phase, since the bacteria have often disappeared from the feces by this stage of the disease. Specific Y. ent. serodiagnostics are benefitted by the fact that no antisera cross-react with the serotype 3 thermostable O-antigen. A titre of greater than or equal to 80 is therefore highly indicative of a recent or current Y. ent. infection. In the absence of other known arthritogenic agents the Y. ent. antibodies are highly indicative of the Y. ent. etiology of a current disease. The Y. ent. complications affect most inflammatory reactive diseases, acute as well as chronic. In an area in which Y. ent. infections are endemic, Y. ent. is the most frequent cause of acute and chronic arthritis. The present results indicate that not all cases of acute Y. ent. arthritis remit, but some persist, usually with an intermittent course, and develop into rheumatoid arthritis or allied conditions. This suggests a common pathogenic mechanism in most inflammatory rheumatic diseases. It is proposed that the time has come for a classification of these diseases based on their etiology, in order to replace the present symptom-based treatment with a causal one, and to institute prophylactic measures. The pathology is not exclusive to Y. ent., but can presumably also be brought about by other bacteria, such as gonococci, meningococci, salmonellae, shigellae, and brucellae, possibly by their content of lipopolysaccharide.

[Guidelines for the laboratory diagnosis of rheumatic diseases (author's transl)]

The methods for laboratory diagnosis of rheumatic diseases are subdivided into 10 groups according to their informative value. The following aspects are taken into consideration: general diagnosis of inflammation, infective processes with hemolytic streptococci and staphylococci, streptococcal agglutinations, rheumatoid factor tests in the strictest sense, detection of autoantibodies, the HLA-system, investigations in metabolic diseases and generalized skeletal diseases, bacteriological and serological investigations in joint infections and tests in symptomatic diseases of joints and muscles. In the evaluation of the individual methods and the discussion of their application in various types of disease, the following provisional diagnoses are gone into: streptococcal rheumatism, rheumatoid arthritis, monarthritis, ankylosing spondylitis, Reiter's syndrome and psoriatic arthritis, myositis and polymyositis.

Recent progress in mycoplasma research

Today, 12 years after the identification of Eaton agent as a mycoplasma, much new information on this infection has accumulated. Better methods have become available, which will be helpful in determining whether other mycoplasmas might be human pathogens, e.g., some ureaplasmas in nongonococcal urethritis. Experimental mycoplasma infections in birds and animals have revealed common features with immune complex diseases in man. They may serve, therefore, as useful models for human mycoplasma disease. However, the most important finding in recent mycoplasma research has been the isolation of mycoplasma viruses. Viruses belonging to three different groups have been discovered. It will be interesting to study whether the virus determines the pathogenicity of mycoplasmas or not.

Growth of Newcastle disease virus and rubella virus in rheumatoid and nonrehumatoid synovial cell cultures

Rheumatoid and nonrheumatoid synovial cell cultures were challenged with Newcastle disease virus and rubella virus in an attempt to confirm reports that rheumatoid synovial cells are relatively resistant to infection with these viruses. Newcastle disease virus caused complete cell destruction by day 7 in both rheumatoid and nonrheumatoid cultures, and peak virus titers were similar. Rubella virus replicated in both rheumatoid and nonrheumatoid synovial cell cultures, and no consistent differences in virus titers were detected. Rubella-infected cell lines were observed for up to 28 days and no virus-specific cytopathic effect was seen.