Muruve, Email: ac.yraglacu@evurumd. Marvin J. by severe pulmonary hemorrhage after immunosuppression, likely due to cytomegalovirus (CMV) pneumonitis. Case presentation A 24-year-old man was admitted to hospital with hemoptysis and renal failure. Investigations for anti-GBM serology by addressable laser bead immunoassay (ALBIA) was unfavorable for anti-GBM antibodies. Renal biopsy showed diffuse endocapillary proliferative glomerulonephritis with membranoproliferative features and diffuse circumferential crescents. Direct IF showed strong linear staining for IgG along GBMs. The patients hemoptysis improved with immunosuppression, but 1 month later he was readmitted with gross hemoptysis, which was refractory to further cyclophosphamide, plasma exchange and rituximab. Bronchoalveolar lavage (BAL) and blood work confirmed CMV pneumonitis, and the patients hemoptysis resolved with ganciclovir, though he became dialysis dependent. Conclusions This case demonstrates an atypical presentation of anti-GBM disease with both crescents and endocapillary hypercellularity and unfavorable serology. The patient is usually dialysis dependent, unlike most previously described patients with atypical anti-GBM disease. The course was complicated by CMV pneumonitis, which contributed to the severity of the pulmonary manifestations and added diagnostic difficulty. prophylaxis. Renal function also improved and at discharge his creatinine was 305?mol/L, following a peak of 454?mol/L. The patient returned to Urgent Care approximately 1 month later with fever, massive hemoptysis, and anuria. Serum creatinine was 1065?mol/L, and he was urgently started on dialysis. Chest X-ray showed worsening of bilateral patchy opacities (Fig. ?(Fig.4).4). Empirical treatment for presumed relapse of his disease was initiated, with 500?mg IV methylprednisolone and plasma exchange with fresh frozen plasma as replacement fluid. He also received empiric ceftriaxone and azithromycin and continued on prednisone 60?mg daily, along with cyclophosphamide, and trimethoprim/sulfamethoxazole. He underwent bronchoscopy, and his bronchoalveolar lavage did not initially reveal an infectious agent, although the respiratory panel was positive for parainfluenza. CMV was not assayed at the time of initial bronchoscopy. Of note, his BAL was persistently bloody but did not meet criteria for diffuse alveolar hemorrhage (his hemosiderin-laden macrophage count was ?20%). The patient was managed for 5?days HJ1 as above but continued to have massive hemoptysis and worsening pulmonary infiltrates radiographically. As a result, rituximab therapy was initiated for possible cyclophosphamide-resistant atypical-anti-GBM disease. The patients clinical condition continued to decline as he required intubation and underwent repeat bronchoscopy. He was empirically treated with piperacillin/tazobactam and linezolid despite all of his blood/alveolar lavage bacterial cultures being unfavorable. His echocardiogram and enhanced chest CT were unremarkable for other etiologies contributing to severe pulmonary hemorrhage. He was subsequently started on empiric ganciclovir for possible cytomegalovirus (CMV) contamination. Results of the second bronchoscopy confirmed CMV and a viral load of ?106?IU/mL from his BAL fluid. Cytology showed inclusion bodies consistent with CMV contamination. His serum showed a CMV load of ?2 million IU/mL. He never had CMV checked prior to this. After initiation of ganciclovir, the patient experienced clinical improvement with resolution of his hemoptysis and chest x-ray abnormalities. His renal function however never recovered, and he remained dialysis dependent. Discussion and conclusions This is a case of a 24-year-old male with aggressive Rotigotine atypical anti-GBM disease who developed recurrent massive hemoptysis after initial apparent response to induction therapy with corticosteroids and cyclophosphamide, subsequently found to have CMV viremia and pneumonitis as the likely cause for his severe clinical deterioration. The atypical pathology with severe phenotype, undetectable anti-GBM serology, and presence of CMV pneumonitis are the three main highlights of this case. To the best of our knowledge, this is the first case of atypical anti-GBM disease with a diffuse crescentic and endocapillary proliferative phenotype. Common anti-GBM disease is usually associated with diffuse crescent formation without endocapillary or mesangial proliferation. [10, 13]. On the other hand, a series of 20 atypical anti-GBM cases reported by Nasr et al.  showed endocapillary and mesangial proliferation, or membranoproliferative glomerulonephritis. Crescents, when present, involved a minority of the glomeruli. In this series, patients tended Rotigotine to have a better renal outcome than common anti-GBM and did not have pulmonary involvement, indicating a more benign illness . Our case appears to deviate from this spectrum, with an aggressive renal disease course and pulmonary involvement, more akin to common anti-GBM disease. There are several possible reasons why histologically confirmed anti-GBM disease may be serologically unfavorable by commercial immunoassays. One possible explanation is usually that the target antigen may be different, and thus the anti-GBM antibody is Rotigotine not detected by conventional laboratory.