Hypercalcemia and pneumocystis Pneumonia after kidney transplantation: report of an exceptional case and literature review

A case of hypercalcemia from Pneumocystis jirovecii in an immunosuppressed non-HIV patient

BACKGROUND

The prevalence of non-HIV related Pneumocystis jirovecii pneumonia (PJP) is increasing with use of immunosuppressive therapies. There are case reports of solid organ transplant recipients on immunosuppressive therapy presenting with mild hypercalcemia, leading to a diagnosis of PJP. Recent studies have shown efficacy of PJP prophylaxis for patients treated with rituximab with a favourable adverse effect profile.

CASE PRESENTATION

A 78-year-old male with a history of PR3-ANCA vasculitis, chronic kidney disease and heart failure with reduced ejection fraction presented to our tertiary care hospital with a two-week history of confusion and non-productive cough. Background immunosuppression with rituximab was completed every six months. The patient was found to have hypercalcemia and new infiltrates and ground glass opacities on cross-sectional imaging. Bronchoscopy was performed that was positive for Pneumocystis jirovecii. He was treated with 21 days of trimethoprim-sulfamethoxazole and prednisone with resolution of symptoms and hypercalcemia.

CONCLUSIONS

Herein, we present a novel case of PJP in a non-transplant recipient preceded by hypercalcemia. Our case demonstrates the importance for a high suspicion for PJP in chronically immunosuppressed patients on rituximab presenting with PTH-independent hypercalcemia.

Rare Causes of Hypercalcemia: 2021 Update

CONTEXT

Primary hyperparathyroidism and malignancy are the etiologies in 90% of cases of hypercalcemia. When these entities are not the etiology of hypercalcemia, uncommon conditions need to be considered. In 2005, Jacobs and Bilezikian published a clinical review of rare causes of hypercalcemia, focusing on mechanisms and pathophysiology. This review is an updated synopsis of rare causes of hypercalcemia, extending the observations of the original article.

EVIDENCE ACQUISITION

Articles reporting rare associations between hypercalcemia and unusual conditions were identified through a comprehensive extensive PubMed-based search using the search terms "hypercalcemia" and "etiology," as well as examining the references in the identified case reports. We categorized the reports by adults vs pediatric and further categorized the adult reports based on etiology. Some included reports lacked definitive assessment of etiology and are reported as unknown mechanism with discussion of likely etiology.

EVIDENCE SYNTHESIS

There is a growing understanding of the breadth of unusual causes of hypercalcemia. When the cause of hypercalcemia is elusive, a focus on mechanism and review of prior reported cases is key to successful determination of the etiology.

CONCLUSIONS

The ever-expanding reports of patients with rare and even unknown mechanisms of hypercalcemia illustrate the need for continued investigation into the complexities of human calcium metabolism.

Causes of hypercalcemia in renal transplant recipients: persistent hyperparathyroidism and others

Hypercalcemia is common in patients after kidney transplantation (KTx) and is associated with persistent hyperparathyroidism in the majority of cases. This retrospective, single-center study evaluated the prevalence of hypercalcemia after KTx. KTx recipients were evaluated for 7 years after receiving kidneys from living or deceased donors. A total of 301 patients were evaluated; 67 patients had hypercalcemia at some point during the follow-up period. The median follow-up time for all 67 patients was 62 months (44; 80). Overall, 45 cases of hypercalcemia were classified as related to persistent post-transplant hyperparathyroidism (group A), 16 were classified as "transient post-transplant hypercalcemia" (group B), and 3 had causes secondary to other diseases (1 related to tuberculosis, 1 related to histoplasmosis, and 1 related to lymphoma). The other 3 patients had hypercalcemia of unknown etiology, which is still under investigation. In group A, the onset of hypercalcemia after KTx was not significantly different from that of the other groups, but the median duration of hypercalcemia in group A was 25 months (12.5; 53), longer than in group B, where the median duration of hypercalcemia was only 12 months (10; 15) (P<0.002). The median parathyroid hormone blood levels around 12 months after KTx were 210 pg/mL (141; 352) in group A and 72.5 pg/mL (54; 95) in group B (P<0.0001). Hypercalcemia post-KTx is not infrequent and its prevalence in this center was 22.2%. Persistent hyperparathyroidism was the most frequent cause, but other important etiologies must not be forgotten, especially granulomatous diseases and malignancies.

Clinical descriptive analysis of severe Pneumocystis jirovecii pneumonia in renal transplantation recipients

Pneumocystis jirovecii (P. jirovecii) pneumonia (PJP) is an opportunistic fungal infection after renal transplantation, which is always severe, difficult to diagnose, combined with multiple complications and have poor prognosis. We retrospectively analyzed clinical data, including risk factors, diagnosis, treatment and complications of seven clinical cases suffered with severe PJP after renal transplantation in our department in 2019. All the seven recipients were routinely prescribed with PJP prophylaxis after renal transplantation, and six of them suffered acute graft rejection before the infection. P. jirovecii sequence was identified in blood or broncho-alveolar lavage fluid (BALF) by the metagenomic next-generation sequencing (mNGS) in all patients. All the patients were improved with the therapy trimethoprim-sulfamethoxazole (TMP-SMX) combined with caspofungin for the PJP treatment, but suffered with complications including renal insufficiency, leukopenia, thrombocytopenia, gastrointestinal bleeding, mediastinalemphysema, pulmonary hemorrhage, and hemophagocytic syndrome and other severe infections. Taken together, mNGS is a powerful tool that could be used to diagnose PJP in renal transplantation recipients. And PJP prophylaxis should be prescribed during and after treatment for acute rejection. TMP-SMX is the first-line and effective drug for PJP treatment, but the complications are always life-threatening and lead to poor prognosis. We should pay attention to these life-threatening complications.

Causes of hypercalcemia in people living with HIV in the HAART era

BACKGROUND

Hypercalcemia is an uncommon finding in people living with HIV (PLHIV). Causes of hypercalcemia in PLHIV have not been well documented. As such, we studied the causes of hypercalcemia in PLHIV.

METHODS

We conducted a retrospective review of PLHIV who had corrected serum calcium of ≥10.5 mg/dL between 2010 and 2019. Demographic data, associated diseases, and treatment details were collected. Corrected serum calcium levels were compared among the causes of hypercalcemia.

RESULTS

A total of 70 of 2168 (3.2%) PLHIV had hypercalcemia. Forty-nine (70.0%) were male with a mean age of 47.7 ± 4.7 years. Only two (2.9%) had symptoms of hypercalcemia. Fifty-four patients had identifiable causes of hypercalcemia; 21 infections (30.0%), 17 solid organ malignancies (24.3%), 14 hematologic malignancies (20.0%), and two other specific causes (2.9%). Mean corrected serum calcium concentrations of PLHIV who had solid organ malignancy, hematologic malignancy, infection, and unknown causes were 12.8 ± 2.1, 11.4 ± 1.0, 11.2 ± 0.6, and 10.8 ± 0.2 mg/dL, respectively. Corrected serum calcium levels were significantly greater in patients who had solid organ malignancy comparing to those with other causes of hypercalcemia (p < 0.05, all). Logistic regression identified solid organ malignancy as the only factor associated with moderate to severe hypercalcemia (odds ratio 12.72, 95% confidence interval 3.11-52.08; p < 0.001).

CONCLUSIONS

Hypercalcemia in PLHIV is associated with solid organ malignancy, hematologic malignancy, and infection. Most PLHIV with hypercalcemia are asymptomatic. Solid organ malignancy is associated with moderate to severe hypercalcemia, and as such PLHIV presenting with moderate to severe hypercalcemia should be investigated for solid organ malignancy.

Hypercalcemia as an Early Finding of Opportunistic Fungal Pneumonia in Renal Transplantation: A Case Series Report

BACKGROUND

Pneumonia caused by opportunistic fungi is a serious complication in immunocompromised patients. Hypercalcemia has been described in renal transplantation associated with Pneumocystis jirovecii (PJP) or Histoplasma capsulatum (HCP) pneumonia.

METHODS

We describe 5 patients who underwent kidney transplant between 2014 and 2019 and developed hypercalcemia before the diagnosis of pulmonary fungal infection: 4 patients with PJP and 1 with HCP. We assessed calcium metabolism and kidney function by total and ionized calcium, phosphorus, intact parathormone (iPTH), 25-OH vitamin D, 1,25(OH)2 vitamin D, and serum creatinine levels.

RESULTS

Mean albumin-corrected calcium and ionized calcium were 12.56 mg/dL (range, 10.8-13.8 mg/dL) and 1.57 mmol/L (range, 1.43-1.69 mmol/L). Patients were normocalcemic, at 10.12 mg/dL (range, 9.6-10.5 mg/dL), before diagnosis and resolved hypercalcemia after antifungal treatment, at 8.86 mg/dL (range, 8.0-9.5 mg/dL). All patients had low or normal iPTH values, at 29.1 pg/mL (range, <3-44 pg/mL), with higher PTH levels 3 months before diagnosis and after treatment, at 147.3 pg/mL (range, 28.1-479 pg/mL) and 117.5 pg/mL (range, 18.2-245 pg/mL), respectively. The mean value for 25-OH vitamin D was 30.8 ng/mL (range, 14.6-62.8 ng/mL). This supports a PTH-independent mechanism, and we postulated an extrarenal production of 1,25(OH)2 vitamin D.

CONCLUSION

In kidney transplant patients, hypercalcemia independent of PTH and refractory to treatment should alert for the possibility of opportunistic fungal pneumonia.

Pneumocystis jirovecii pneumonitis: cause of acute hypercalcaemia in chronic haemodialysis patient

A 76-year-old renal transplant patient due to autosomal dominant polycystic kidney disease who resumed chronic haemodialysis was admitted to our hospital for confusion and lassitude. He was afebrile and physical examination revealed diffuse bilateral rales with decreased respiratory sounds in lower right lung. Laboratory data showed hypercalcaemia (total calcium 3.92 mmol/L (normal range 2.2-2.6 mmol/L), ionised calcium 1.87 mmol/L (1.15-1.35 mmol/L)), low intact parathyroid hormone (iPTH) 15 ng/L, (15-65 ng/L) and high 1,25(OH)2D3 128.9 pg/mL, (15.2-90.1 pg/mL). Chest CT-scan revealed bilateral apical lung lesions after 15 days of antibiotics. Bronchoalveolar sample was PCR positive for Pneumocystis jirovecii He was treated with an extra session of haemodialysis with 1.25 mmol/L dialysate calcium concentration, oral trimethoprim-sulfamethoxazole was started and oral corticosteroid dose increased to 1 mg/kg for 1 week. Hypercalcaemia decreased progressively after initiation of these treatments. We concluded a case of hypercalcaemia secondary to P. jirovecii infection.

Hypercalcemia Heralding Pneumocystis jirovecii Pneumonia in an HIV-Seronegative Patient with Diffuse Cutaneous Systemic Sclerosis

Pneumocystis pneumonia (PCP) is a life-threatening fungal infection occurring in immunocompromised patients such as HIV-positive patients with low CD4 cell count or patients under heavy immunosuppressive therapy. We report the case of a 59-year-old male with severe diffuse cutaneous systemic sclerosis presenting with asthenia, dry cough and worsening shortness of breath for the last 15 days. Biological studies were remarkable for PTH-independent severe hypercalcemia with low 25-hydroxyvitamin D and a paradoxically elevated 1,25-dihydroxyvitamin D. Early bronchoalveolar lavage allowed for PCP diagnosis and targeted treatment. We discuss the underlying physiopathology and difficulties regarding prophylaxis and treatment.

Hypercalcemia associated with Pneumocystis jirovecii pneumonia in renal transplant recipients: case report and literature review

Background: Pneumocystis jirovecii associated pneumonia is a potentially life-threatening opportunistic infection, occurring most frequently in the first year after renal transplantation, and may be associated with hypercalcemia. Clinical presentation:We report the case of a renal transplant recipient presenting with Pneumocystis jirovecii associated pneumonia and hypercalcemia due to ectopic production of 1,25-dihydroxyvitamin D, 6 years after renal transplantation. Calcemia and 1-25 hydroxyvitamin D levels normalized after our patient was treated by trimethoprim-sulfamethoxazole. Discussion: We review similar cases to delineate the clinical and biological profile of patients with Pneumocystis jirovecii pneumonia associated hypercalcemia. Conclusion:Physicians should evoke this diagnosis in renal transplant recipients presenting with pulmonary infection associated with hypercalcemia.

Hypercalcemia is common during Pneumocystis pneumonia in kidney transplant recipients

A few cases of hypercalcemia related to Pneumocystis jirovecii pneumonia (PJP) have previously been described, supposedly associated with an 1α-hydroxylase enzyme-dependent mechanism. The prevalence and significance of hypercalcemia in PJP remain unclear, especially in kidney transplant recipients (KTR) who frequently display hypercalcemia via persisting hyperparathyroidism. We here retrospectively identified all microbiologically-proven PJP in adult KTR from 2005 to 2017 in the Lille University Hospital, and studied the mineral and bone metabolism parameters during the peri-infectious period. Clinical features of PJP-patients were analyzed according to their serum calcium level. Hypercalcemia (12.6 ± 1.6 mg/dl) was observed in 37% (18/49) of PJP-patients and regressed concomitantly to specific anti-infectious treatment in all cases. No other cause of hypercalcemia was identified. In hypercalcemic patients, serum levels of 1,25-dihydroxyvitamin D were high at the time of PJP-diagnosis and decreased after anti-infectious treatment (124 ± 62 versus 28 ± 23 pg/mL, p = 0.006) while PTH serum levels followed an inverse curve (35 ± 34 versus 137 ± 99 pg/mL, p = 0.009), suggesting together a granuloma-mediated mechanism. Febrile dyspnea was less frequent in hypercalcemic PJP-patients compared to non-hypercalcemic (29 versus 67%). In summary, hypercalcemia seems common during PJP in KTR. Unexplained hypercalcemia could thus lead to specific investigations in this particular population, even in the absence of infectious or respiratory symptoms.

Severe hypercalcemia preceding a diagnosis of Pneumocystis jirovecii pneumonia in a liver transplant recipient

Background

Incidence of the opportunistic infection Pneumocystis jirovecii pneumonia (PJP) in solid organ transplant patients ranges from 5 to 15% with a mortality of up to 38%.

Case presentation

We present a liver transplant recipient who developed hypoxemic respiratory failure related to PJP soon after treatment for allograft rejection. His presentation was preceded by severe hypercalcemia of 14.6 mg/dL and an ionized calcium of 1.7 mmol/L which remained elevated despite usual medical management and eventually required renal replacement therapy. As approximately 5% of PJP cases have granulomas, here we review the role of pulmonary macrophages and inflammatory cytokines in the pathophysiology of granuloma-mediated hypercalcemia. We also discuss the interpretation of our patient’s laboratory studies, response to medical therapy, and clinical risk factors which predisposed him to PJP.

Conclusions

It is important for clinicians to consider PJP as an etiology of granulomatous pneumonia and non-parathyroid hormone mediated hypercalcemia in chronically immunosuppressed organ transplant recipients for timely diagnosis and management.

A case of Pneumocystis pneumonia, with a granulomatous response and vitamin D-mediated hypercalcemia, presenting 13 years after renal transplantation

Vitamin D-mediated hypercalcemia is an uncommon complication of Pneumocystis infection. A granulomatous response resulting from Pneumocystis infection is also atypical. In this report, we describe an exceptional case of granulomatous Pneumocystis pneumonia associated with vitamin D-mediated hypercalcemia, in a patient who presented unusually late after renal transplantation. The patient's hypercalcemia resolved with treatment of the infection.

Acute Kidney Injury Secondary to Hypercalcemia in a Kidney Transplant Patient With Pneumocystis jirovecii Pneumonia: A Case Report

BACKGROUND

Persistent hyperparathyroidism is one of the main causes of hypercalcemia following kidney transplantation; differential diagnosis is required.

CASE PRESENTATION

We report the case of a 61-year-old kidney transplant recipient who underwent transplant in September 2016. She was admitted in March 2017 presenting with a 3-week history of asthenia, hypotension, and cough. Laboratory analysis showed acute kidney injury with hypercalcemia and elevation of inflammatory markers. She was initially treated with hydration therapy. A few days after admission she developed respiratory failure: chest computed tomography showed a ground-glass pattern. A diagnosis of Pneumocystis jirovecii was made on bronchoalveolar lavage. A subsequent graft biopsy was performed that revealed intratubular calcium deposition without signs of rejection. The patient was given trimethoprim/sulfamethoxazole, with improvement in pulmonary and renal function as well as improvement in hypercalcemia.

CONCLUSIONS

P jirovecii infection can trigger activation of intra-alveolar macrophages that leads to extrarenal vitamin D production with subsequent hypercalcemia. This rare event should be considered in renal transplant patients with pulmonary infection accompanied by hypercalcemia. In our case, hypercalcemia also provoked acute kidney injury.

Hypercalcaemia preceding diagnosis of Pneumocystis jirovecii pneumonia in renal transplant recipients

BACKGROUND

The overall incidence of Pneumocystis jirovecii pneumonia (PJP) in solid organ transplant recipients is 5-15%. A timely diagnosis of PJP is difficult and relies on imaging and detection of the organism.

METHODS

We present a case series of four patients displaying hypercalcaemia with an eventual diagnosis of PJP and document the management of the outbreak with a multidisciplinary team approach. We discuss the underlying pathophysiology and previous reports of hypercalcaemia preceding a diagnosis of PJP. We also reviewed the evidence concerning PJP diagnosis and treatment.

RESULTS

Within our renal transplant cohort, four patients presented within 7 months with hypercalcaemia followed by an eventual diagnosis of PJP. We measured their corrected calcium, parathyroid hormone (PTH), 1,25-dihydroxycholecalciferol [1,25-(OH)2D3] and 25-hydroxycholecalciferol [25(OH)D] levels at admission and following treatment of PJP. All four patients diagnosed with PJP were 4-20 years post-transplantation. Three of the four patients demonstrated PTH-independent hypercalcaemia (corrected calcium >3.0 mmol/L). The presence of high 1,25(OH)2D3 and low 25(OH)D levels suggest negation of the negative feedback mechanism possibly due to an extrarenal source; in this case, the alveolar macrophages. All four patients had resolution of their hypercalcaemia after treatment of PJP.

CONCLUSIONS

Given the outbreak of PJP in our renal transplant cohort, and based on previous experience from other units nationally, we implemented cohort-wide prophylaxis with trimethoprim-sulphamethoxazole for 12 months in consultation with our local infectious diseases unit. Within this period there have been no further local cases of PJP.

Mineral and bone disorder after kidney transplantation

After successful kidney transplantation, accumulated waste products and electrolytes are excreted and regulatory hormones return to normal levels. Despite the improvement in mineral metabolites and mineral regulating hormones after kidney transplantation, abnormal bone and mineral metabolism continues to present in most patients. During the first 3 mo, fibroblast growth factor-23 (FGF-23) and parathyroid hormone levels decrease rapidly in association with an increase in 1,25-dihydroxyvitamin D production. Renal phosphate excretion resumes and serum calcium, if elevated before, returns toward normal levels. FGF-23 excess during the first 3-12 mo results in exaggerated renal phosphate loss and hypophosphatemia occurs in some patients. After 1 year, FGF-23 and serum phosphate return to normal levels but persistent hyperparathyroidism remains in some patients. The progression of vascular calcification also attenuates. High dose corticosteroid and persistent hyperparathyroidism are the most important factors influencing abnormal bone and mineral metabolism in long-term kidney transplant (KT) recipients. Bone loss occurs at a highest rate during the first 6-12 mo after transplantation. Measurement of bone mineral density is recommended in patients with estimated glomerular filtration rate > 30 mL/min. The use of active vitamin D with or without bisphosphonate is effective in preventing early post-transplant bone loss. Steroid withdrawal regimen is also beneficial in preservation of bone mass in long-term. Calcimimetic is an alternative therapy to parathyroidectomy in KT recipients with persistent hyperparathyroidism. If parathyroidectomy is required, subtotal to near total parathyroidectomy is recommended. Performing parathyroidectomy during the waiting period prior to transplantation is also preferred in patients with severe hyperparathyroidism associated with hypercalcemia.

Pneumocystis jirovecii pneumonia with an atypical granulomatous response after kidney transplantation

Pneumocystis jirovecii pneumonia (PCP) continues to be a leading cause of morbidity and mortality in kidney transplant recipients. Granulomatous PCP is an unusual histological presentation that has been described in a variety of immunosuppressive conditions. Previous studies have demonstrated an association between granulomatous disorders and hypercalcemia, the purported mechanism of which is extrarenal production of 1,25-dihydroxyvitamin D by activated macrophages. Here, we report a case of granulomatous formation in a kidney transplant recipient with PCP who presented with hypercalcemia and suppressed parathyroid hormone, both of which resolved after successful treatment of the pneumonia. In immunocompromised patients, pulmonary infection associated with hypercalcemia should raise the suspicion of PCP and other granulomatous disorders.