Acquired thrombotic thrombocytopenic purpura associated with reversible severe renal failure requiring hemodialysis.

Thrombotic thrombocytopenic purpura (TTP) is an uncommon hematologic disorder characterized by microangiopathic hemolytic anemia (MHA) and thrombocytopenia with or without fever, renal failure, and neurologic manifestations. Although the full pentad was required for the diagnosis of TTP until recently, because of the high mortality of untreated TTP and the varying manifestations of the disease itself, diagnostic criteria for TTP have been relaxed since the emergence of plasma exchange as effective treatment for TTP. The occurrence of MHA and thrombocytopenia without an alternate cause is now sufficient to initiate therapy. Renal dysfunction in acquired TTP, when it occurs, is transient and responds to therapeutic plasma exchange readily. Here we report a patient with acquired TTP who had no preexisting renal pathology but developed severe prolonged renal failure requiring multiple rounds of hemodialysis with eventual complete recovery of renal function. We adopted an intensive approach including steroids, rituximab, cyclosporine, twice daily plasma exchange, and hemodialysis. We believe that this was responsible for complete recovery of the patient. However, the reason for this unusually severe renal manifestation needs further study.

Disseminated Mycobacterium gordonae infection in an immunocompetent host.

Mycobacterium gordonae is a slow-growing mycobacterium that is the least pathogenic of the mycobacteria. Infection with M. gordonae is most commonly reported in immunocompromised patients. We present a rare case of M. gordonae infection in an immunocompetent individual. A 37-year-old woman was found to have a pulmonary nodule in the left upper lobe. The patient denied any respiratory symptoms, including cough, sputum production, fever, chest pain, or shortness of breath. The patient was a lifetime nonsmoker. Physical examination was normal. Computed tomography (CT) scan of the chest revealed several discrete pleural-based inflammatory infiltrates bilaterally. The patient was treated with oral amoxicillin-clavulinic acid initially and a repeat CT scan chest was scheduled after 2 weeks. Laboratory data were nonsignificant. Repeat CT scan did not show any resolution. Patient positron emission tomography scan revealed marked hypermetabolic uptake involving bilateral parenchymal nodules, mediastinal lymph nodes, and the spleen. A thoracotomy with biopsy of the left upper lobe nodule revealed necrotizing granulomatous pneumonitis with rare acid-fast bacilli. Cultures were positive for M. gordonae. The patient was started on a multidrug regimen of azithromycin, rifampin, and ciprofloxacin, based on drug sensitivities, for 12 months. Repeat CT scan and positron emission tomography scan after treatment showed complete resolution. The patient has remained disease-free 5 years after treatment. Instead of always dismissing M. gordonae as a contaminant, we should include it in our differential diagnosis of pulmonary infection in both immunocompetent and immunocompromised hosts. Further studies are needed to understand the pathogenesis of M. gordonae infection in humans.

Babesiosis as a cause of fever in patients undergoing a splenectomy.

Babesiosis is an emerging infection most commonly acquired from a tick bite. We describe three hospitalized patients with fever attributable to babesiosis after a splenectomy. Splenectomy was done because of splenic enlargement due to unsuspected babesia infection in one patient and because of splenic perforation due to babesiosis in a second patient. The third patient underwent splenectomy for trauma and acquired babesiosis postoperatively from a blood transfusion. Our cases demonstrate the need to be vigilant for babesiosis in patients undergoing splenectomy.

Emergence of resistance to azithromycin-atovaquone in immunocompromised patients with Babesia microti infection.

BACKGROUND: Babesiosis is an emerging tickborne malaria-like infection principally caused by Babesia microti. This infection typically resolves either spontaneously or after administration of a 7-10-day course of azithromycin plus atovaquone or clindamycin plus quinine. Although certain highly immunocompromised patients may respond suboptimally to these drug regimens, unlike the situation with malaria there has been no reported evidence that the cause of treatment failure is infection with drug-resistant strains of B. microti. METHODS: Emergence of drug resistance in B. microti was defined as the development of a microbiologic relapse (recurrent parasitemia or a marked increase in parasitemia) in association with both clinical and laboratory abnormalities indicative of active babesiosis in a patient after 28 days of uninterrupted antibabesia drug therapy and while still receiving treatment. RESULTS: The clinical case histories of 3 highly immunocompromised patients who received a subcurative course of azithromycin-atovaquone associated with the eventual development of resistance to this drug regimen are described. One of the 3 patients died of complications related to babesiosis. CONCLUSIONS: B. microti may become resistant to azithromycin-atovaquone during the treatment of babesiosis with this combined drug regimen in highly immunocompromised patients. Although research is needed to determine the optimal therapy for highly immunocompromised patients with babesiosis, reducing the level of immunosuppression when possible would appear to be a desirable strategy.

Cardiac manifestations of sarcoidosis and therapeutic options.

Sarcoidosis is a multisystem disorder of unknown etiology, characterized by granulomatous infiltration and the development of noncaseating granulomas in many organ systems. Although the lungs, eyes, and skin are most commonly affected, virtually any body organ can be involved. Clinical evidence of sarcoid heart disease (SHD) is seen only in 5% of patients and the disease may present with tachyarrhythmias, conduction disturbance, heart failure, or sudden cardiac death. SHD may present at any age and occurs in all ethnic groups. Cardiac involvement, although typically silent, is an important prognostic factor in sarcoidosis. Various diagnostic tests such as the electrocardiogram, two-dimensional echocardiography, cardiac magnetic resonance imaging, positron emission tomography scan, radionuclide scan, and a transvenous endomyocardial biopsy are available for the early detection of cardiac involvement in sarcoidosis. Given that early diagnosis and treatment may prevent substantial morbidity and mortality in patients with cardiac involvement, it remains important to screen patients with sarcoidosis and initiate early treatment with corticosteroids. Other immunosuppressive agents, antiarrhythmic drugs, placement of an automated implantable cardiac defibrillator, or surgical options such as a pericardial window, ventricular aneurysm repair and cardiac transplant, may also be required for the management of patients with SHD.