BACKGROUND: Advanced HIV disease (AHD) is increasing, with late presentation accounting for half of newly diagnosed people with HIV (PWH) in Europe. Mortality in late-presenting PWH remains high, and Mycobacterium avium complex (MAC) disease, among other opportunistic infections, presents several diagnostic and treatment challenges that lead, ultimately, to a poor clinical outcome.
OBJECTIVE: We aimed to provide guidance on the diagnosis and treatment of disseminated MAC disease (dMACd) in PWH.
METHODS: We performed a review of original articles, meta-analyses, and systematic reviews retrieved from PubMed.
BACKGROUND: We reviewed and discussed the most challenging steps in the management of PWH with AHD and dMACd: the current epidemiology in the era of effective antiretroviral treatment (ART); clinical presentation and interpretation of symptoms in the context of other opportunistic infections and immune reconstitution; diagnosis, sampling, and timing to reach a definitive diagnosis; prophylaxis, treatment options, and indications for discontinuing MAC treatment; future perspectives, and the role of rifamycins in the treatment of dMACd.
CONCLUSIONS: Despite the widespread availability of effective ART, dMACd still represents a major cause of morbidity and mortality in PWH with AHD. Residual challenges are mainly related to the difficulties and timing required to reach a definitive diagnosis, and the discussion regarding the role of rifamycins in the treatment of dMACd is still open.

Mycobacterium avium complex (MAC) is an important cause of opportunistic infections in immunosuppressed hosts, such as patients with HIV infection and solid organ transplant recipients. MAC disease usually presents in 4 distinct clinical categories: chronic pulmonary disease, disseminated disease, skin/soft-tissue infection, and superficial lymphadenitis. However, clinical reports on gastrointestinal (GI) MAC disease are rare, especially in patients without HIV infection or a history of organ transplantation. We describe a case of non-HIV-associated GI MAC disease in a patient with long-term mycophenolate mofetil use. In this case, MAC organisms in the GI tract and ascites were observed. Endoscopy revealed a unique colonic image with large, deep epithelial denudations. This suggests that apart from patients with HIV infection or transplant recipients, those treated with immunosuppressants can have disseminated MAC. Therefore, internal physicians need to monitor patients undergoing mycophenolate mofetil immunosuppressant therapy.

BACKGROUND: Anti-interferon-gamma autoantibody-associated immunodeficiency syndrome is a rare and underrecognized adult onset immunodeficiency syndrome associated with severe opportunistic infections such as disseminated nontuberculous mycobacterium. Few cases have documented a relationship with IgG4-related disease. Concomitant diagnoses of these diseases present a diagnostic and management challenge.
METHODS: A 61 year old man of Southeast Asian descent with pulmonary mycobacterium avium complex infection presented to our hospital system with a new skin rash and worsening lymphadenopathy. He was eventually diagnosed with IgG4-related disease through excisional nodal biopsy. He was managed with immunosuppressive treatment with prednisone, rituximab and cyclophosphamide. He later re-presented with disseminated mycobacterium avium complex infiltration of his joints, bones and prostate. Original titers of anti-interferon-gamma autoantibodies were falsely negative due to being on immunosuppressive therapy for his IgG4-related disease. However, anti-interferon-gamma autoantibody titers were re-sent after immunosuppression was held and returned strongly positive.
CONCLUSIONS: This case reviews diagnostic criteria and discusses management strategies with existing challenges in treating a patient with concomitant adult onset immunodeficiency syndrome, IgG4-related disease and a disseminated mycobacterial avium complex infection.

Mycobacterium avium complex (MAC) is a ubiquitous environmental pathogen that was infrequently reported as a cause of disease before the human immunodeficiency virus (HIV)/acquired immune deficiency syndrome epidemic. We present a case of MAC pyomyositis and bacteremia in a 59-year-old man with chronic lymphocytic leukemia in remission after an allogenic stem cell transplant. His posttransplant course was complicated by graft-versus-host disease, requiring treatment with oral steroids and ruxolitinib. In this report, we review the literature on disseminated MAC infection in patients with and without HIV. We also propose a potential mechanism by which this patient may have developed disseminated disease. Disseminated MAC myositis is uncommon in persons without HIV and requires a high index of suspicion for timely diagnosis.

UNASSIGNED: An 8-year-old domestic shorthair cat receiving long-term ciclosporin treatment was evaluated for a history of weight loss and hyporexia. The main clinical finding was a cluster of enlarged mesenteric lymph nodes. Cytological examination of fine-needle aspirates showed granulomatous inflammation with abundant acid-fast bacilli. A diagnosis of Mycobacterium avium complex (MAC) infection was confirmed by PCR. The cat\'s clinical condition deteriorated rapidly despite appropriate antibiotic treatment and it was euthanased 2 weeks after initial presentation due to development of severe paraparesis and ataxia. Post-mortem examination revealed granulomatous inflammation affecting multiple lymph nodes and other organs with intrahistiocytic acid-fast bacilli consistent with mycobacteria when stained using Ziehl-Neelsen stain. Another cat in the same household was screened for infection using the interferon gamma release assay (IGRA), with the result being consistent with infection by non-tuberculous mycobacteria (NTM), which includes MAC; however, it had no grossly detectable disease.
UNASSIGNED: This case report is an unusual presentation of disseminated MAC infection in a cat, which remains a rare diagnosis. Clinicians should be aware of unusual and rare presentations of this infection. The clinical findings, progression of disease and histopathology results add to the current clinical database for feline disseminated MAC infections. Another cat in the same household tested positive for NTM by IGRA without any gross disease. This was suggestive of latent MAC infection which, to our knowledge, has not been previously reported in an in-contact cat.

A 61-year-old woman was admitted for long-lasting fever and recurrent opportunistic infections during the treatment of SLE. She had been diagnosed as SLE and type-IV nephritis based on a renal biopsy and serological findings. A colonoscopy and liver biopsy revealed disseminated Mycobacterium avium complex infection. Human immunodeficiency virus (HIV) infection status was then examined and found to be positive. From the clinical course, the first symptoms were inferred to have been those of HIV infection.