Increasing values of serum acid phosphatase in a child with Mycoplasma pneumoniae-associated hemophagocytic histiocytic syndrome

Adult Onset Still's Disease Associated with Mycoplasma pneumoniae Infection and Hemophagocytic Lymphohistiocytosis

Adult Onset Still's Disease (AOSD) is a systemic inflammatory disorder that can be associated with hemophagocytic lymphohistiocytosis (HLH), a rare but potentially fatal disease of overactive histiocytes and lymphocytes. We present a unique case of AOSD complicated by Mycoplasma pneumonia infection and HLH. A 28-year-old female developed joint pains followed by a diffuse, erythematous, pruritic skin rash that quickly spread throughout the body. The patient deteriorated and developed fever, chills, cough, and dyspnea and had to be intubated. She had hypoalbuminemia, elevated liver enzymes, a very high serum ferritin level, positive anti-Mycoplasma pneumonia IgG and IgM antibodies, and normal rheumatoid factor and anti-nuclear antibodies. The chest X-ray showed diffuse bilateral infiltrates. Bone marrow biopsy revealed hemophagocytosis. The patient was treated with azithromycin, methylprednisolone, and anakinra and was discharged home on cyclosporine and prednisone. This case highlights that patients can develop features of both AOSD and HLH at the beginning of the disease and early diagnosis and treatment increase the likelihood of recovery.

Hemophagocytic lymphohistiocytosis secondary to Mycoplasma pneumoniae infection without pneumonia

Mycoplasma pneumoniae typically causes respiratory tract infections, including pneumonia. We herein report the case of a 30-year-old Japanese woman with hemophagocytic lymphohistiocytosis (HLH), which is rarely caused by bacteria, secondary to Mycoplasma pneumoniae infection and ensuing hypercytokinemia without pneumonia who was successfully treated with a combination of antibiotics and corticosteroids. Therefore, Mycoplasma pneumoniae infection, which is treatable with antibiotics, should be considered a possible trigger of HLH in patients who present with a viral-like illness without pneumonia.

Clinical assessment of Mycoplasma pneumoniae-associated hemophagocytic lymphohistiocytosis

BACKGROUND

Mycoplasma pneumoniae has been reported to be an etiologic pathogen of infection-associated hemophagocytic lymphohistiocytosis (HLH), but few case reports have been available to date.

METHODS

The clinical features of four childhood cases of M. pneumoniae-associated hemophagocytic lymphohistiocytosis (Mp-HLH) were retrospectively assessed to obtain data that might be useful for early diagnosis and effective management. The previous English-language literature pertaining to Mp-HLH was also reviewed.

RESULTS

The patients were two boys and two girls, aged between 1 and 11 years of age. One patient was demonstrated to have concurrent infection with rubella. All the patients had typical radiographic features of M. pneumoniae pneumonia, and one patient also had encephalopathy as a complication. All the children underwent bone marrow examination because of antibiotic-refractory fever, mild hepatosplenomegaly, cytopenia, hyperferritinemia and elevated levels of urine beta2-microglobulin. Cytopenia and hepatosplenomegaly in the present patients were relatively mild as compared to those in cases of other infection-associated HLH such as Epstein-Barr virus infection-associated HLH. Treatment with corticosteroids resulted in prompt and complete resolution in two cases, and i.v. high-dose gammaglobulin therapy achieved a complete response in another child. Spontaneous resolution under treatment with antibiotics alone was observed in one case.

CONCLUSION

Although Mp-HLH is a rare complication of M. pneumoniae infection, it should always be considered in patients with antibiotic-refractory M. pneumoniae infections with cytopenia. Mp-HLH might be effectively treated by corticosteroids or high-dose gammaglobulin. To clarify the diverse clinical manifestations of M. pneumoniae infections, immunological interactions between M. pneumoniae and the host immune system should be further investigated.

Aplastic anemia after Mycoplasma pneumoniae infection: a report of two cases

Two very unusual cases of aplastic anemia complicating mycoplasma infection are described. Each patient had preexisting hematologic abnormalities at the time of the infection: reactive hemophagocytic syndrome in one, and autoimmune hemolytic anemia associated with cold autoantibodies in the other. This adds another entity to the protean manifestations of Mycoplasma pneumoniae infection.