idiopathic cd4 lymphocytopenia ( icl ) is a rare , heterogeneous disorder defined by repeated measurements of the cd4 t lymphocyte count less than 300 cells/l or less than 20 percent of total t lymphocytes in the absence of hiv infection or other etiology known to cause low cd4 cell counts . patients with icl often also have a deficiency in cd8 t cells , b cells , and/or nk cells . in published reports , icl has been noted to occur in association with malignancies , and autoimmune disorders . diagnosis of icl is commonly made in the setting of opportunistic infections such as cryptococcus and non - tuberculous mycobacteria . associations with a number of autoimmune disorders have been reported , including sjogrens syndrome , sarcoidosis , and psoriasis . because of reports of icl co - occurring with autoimmune diseases and because some icl patients have positive antinuclear antibodies ( anas ) , icl may have an underlying autoimmune etiology . icl was first described in 1989 in case reports of severe opportunistic infections and cd4 lymphocytopenia in hiv - negative patients in the u.s . and abroad . in 1992 , the cdc named and defined the disease and assembled a task force that reviewed the 230,179 reported aids cases . from this , 47 patients with icl were identified , 40% of which had aids - defining illnesses , 53% had conditions that were not aids - defining , and only 6% were asymptomatic . furthermore , there is no evidence of transmissibility of icl among sex partners , children , blood donors . to date we report an unusual case of a patient with icl and uncontrolled diabetes who was diagnosed with giant cell arteritis ( gca ) , prescribed prednisone , and subsequently developed pulmonary mucormycosis . a 57-year - old caucasian man with past medical history significant for type 2 diabetes mellitus and stage v chronic kidney disease presented to an outside hospital ( day 0 ) with a severe headache and proximal muscle weakness . temporal artery biopsy was diagnostic for gca , and clinical exam was consistent with polymyalgia rheumatica . two weeks later he was admitted to our hospital ( day 14 ) because of a worsening headache . complete blood count with differential revealed a white cell count of 9.110/l and lymphocyte count of 430/l ; flow cytometry was ordered to further evaluate this lymphopenia . his headache improved , and he was promptly discharged . flow cytometric analysis was resulted after discharge and showed a lymphocyte count of 240/l , cd4 count of 60/l , cd8 count of 120/l , and a cd4:cd8 ratio of 0.5 ; the patient was advised to follow up with his primary care physician , and appropriate prophylaxis was initiated . based on review of cbc results , the patient had lymphopenia prior to initiation of prednisone , but flow cytometry was never performed at outside institutions . western blot and pcr performed at our institution confirmed that he was hiv - negative . four days later ( day 18 ) he re - presented with fever and weakness . during this hospitalization he experienced severe right - sided chest pain , and decreased breath sounds were appreciated at the right apex . 1 ) , and a subsequent computed tomography ( ct ) scan of the chest showed a rounded area of airspace opacity in the right upper lobe with central cavitation and surrounding ground glass halo ( fig . 2 ) , an appearance consistent with angioinvasive fungal infection . additionally , ( 1,3)-beta - d - glucan was elevated at 166  pg / ml . therefore , he was started on liposomal amphotericin b ( 5  mg / kg qd ) . subsequent right upper lobe biopsy revealed broad , irregular , ribbon - like pauciseptate hyphae with wide angle branching , consistent with mucormycosis ( fig . he was transitioned to oral posaconazole 300  mg daily , with liposomal amphotericin b overlap for one more week . repeat flow cytometry during this admission revealed a cd4 count of 154/l , cd8 count of 144/l , and cd4:cd8 ratio of 1.1 . this patients management was complicated by active bleeding from multiple sites ; he was anticoagulated with heparin due to prior deep venous thrombosis . surgical debridement was considered because of evidence suggesting this improves survival in patients with mucormycosis ; however , this patient was a poor surgical candidate and chose to proceed with medical management alone . pulmonary mucormycosis is acquired by inhalation of fungal spores belonging to zygomycetes of the order , mucorales , specifically mucoromycotina . however , a variety of other organisms , including cunninghamella bertholletiae , rhizomucor pusillus , and others can all cause a similar clinical disease state . infections caused by these organisms can rapidly progress to infarction and necrosis of surrounding tissue . diabetes mellitus is the strongest risk factor , as the infecting rhizopus organisms thrive in the setting of diabetic ketoacidosis , although the more common presentation of mucormycosis in diabetic patients is rhino - orbital - cerebral . other risk factors include hematologic malignancies , treatment with glucocorticoids , hematopoietic stem cell and solid organ transplants , iron overload , and aids . iv posaconazole is used in patients who do not respond to or can not tolerate amphotericin b. additionally , urgent surgical debridement is recommended . survival for mucormycosis remains poor ; survival is worst for disseminated mucormycosis , followed by gastrointestinal , pulmonary , and rhino - orbital - cerebral . a recent meta - analysis of 258 icl case reports since 1989 demonstrated that 87.6% of icl patients had at least one opportunistic infection , with the most common being cryptococcus , mycobacteria , candida , and varicella zoster virus ( vzv ) . malignancies were found in 18% of patients , with the most common being lymphoma , squamous cell carcinoma of the skin , and kaposis sarcoma . lastly , autoimmune diseases were seen in 14% , with sjogrens syndrome , sarcoidosis , and psoriasis being the most common . they also found that the mean initial cd4 count was 142.6/l , cd8 count 295/l , and the cd4:cd8 ratio 0.6 . none of the patients analyzed in this study had gca or mucormycosis . a low cd8 count ( < 180/l ) is often seen in icl , including our patient , and is associated with higher risk of opportunistic infection and associated death . our patient was at an increased risk of mucormycosis due to icl , uncontrolled diabetes , and use of prednisone for gca . some studies have demonstrated evidence of increased activation and turnover of cd4 cells ; excess cd4 apoptosis may be due to overexpression of fas / fasl . another theory is that an inflamed , leaky gut allows more microbes to get through gut wall , as evidenced by the observation of elevated lps in icl patients . defective cxcr4 expression by t cells   and defects in the cd3-tcr pathway have also been suggested . lastly , there is also evidence of autoimmune etiology ; one case report described a patient with autoantibodies selective to cd4 + cells , which is consistent with the many reports of comorbid autoimmune conditions in icl . there are no sufficient treatments for icl ; treatment is aimed at preventing and treating opportunistic infections and other comorbidities .
idiopathic cd4 lymphocytopenia ( icl ) is characterized by a low cd4 + lymphocyte count in the absence of hiv or other underlying etiologies . 
 we report a case of a 57-year old man with icl and giant cell arteritis ( gca ) who developed pulmonary mucormycosis , which , to our knowledge , is the first report of these occurring in a patient with icl . 
 abnormally low total lymphocyte or cd4 + cell counts occurring in patients with autoimmune disorders should alert clinicians to the possibility of icl . 
 immunosuppressive treatment should be used with caution in this context .